KOISE
FA
U. S. ENVIRONMENTAL PROTECTION
AGENCY
WASHINGTON, D. C. 20450
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NOISE FACTS DIGEST
June 1972
for the
US BWJra*MB*TAL PROTECT ION AGENCY
OFFICE OF NOISE ABATEMENT AM) CONTROL
WASHINGTON, DC 20460
by
INFORMATICS INC.
under
CONTRACT 68-01-0512
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INTRODUCTION
This pilot issue of Noise Facts Digest has been
prepared in response to a widely expressed need for more and
better information on the prevention, abatement and control of
noise.
It contains two general-interest articles as well as
about two hundred abstracts of material selected from the most
recent and significant of the domestic and foreign literature.
These abstracts are designed to provide substantive informa-
tion. Publications which have been judged difficult to obtain or
use have been abstracted at greater length than those judged
easy to obtain. All abstracts are supported by detailed biblio-
graphic data in order to enable the reader to obtain the source
document directly. We would be pleased to assist you whenever
a source document is difficult to obtain. Material was selected
for abstracting on the basis of its potential interest to a wide
range of readers including not only specialists in noise abate-
ment and control, but also state and local officials, planners,
builders, highway engineers and all those who are only
peripherally concerned with noise.
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Although the Digest concentrates on factual
information, we have widened its scope to include opinions and
recommendations presented at the EPA Hearings on noise held
last year. These witness statements provide the reader with an
opportunity to obtain an impression of the problem of noise in
America as seen from many different viewpoints.
This issue presents the sub-topics of noise compre-
hensively. Possible future issues might be dedicated to one or
two special topics. We are actively seeking the reader's com-
ments and suggestions. Please fill out and return the User
Response Form as soon as you have finished perusing this
issue. Thank you for your cooperation.
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TABLE OF CONTENTS
1NTRODUCTI ON
FEATURES
Chicago's New Noise Ordinance-
The First Year 1
New Noise Information Retrieval System Now on Line 15
ABSTRACTS
EPA Hearings 17
Noise Subject Field and Scope Notes 42
INDEXES
Subject Index (BLUE) 147
Author Index (BLUE) 164
Glossary, Abbreviations, Acronyms (YELLOW) 168
List of Sources (WHITE) 197
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CHICAGO'S NEW NOISE ORDINANCE - THE FIRST YEAR
Almost a year has passed since the 1971 Chicago Noise Ordi-
nance went into effect, and it is now possible to assess its preliminary
impact. There have been two basic reactions noted. The first is the
great interest shown by other communities in the Chicago ordinance.
Among the hundreds of inquiries received by the Chicago Department of
Environmental Control have been many from other towns and cities seeking
to develop their own anti-noise legislation or implement noise control pro-
grams. Indeed, the noise ordinance recently passed (June 1972) by the city
of Baltimore is modeled closely on the Chicago legislation.
The second, and more immediate, reaction to the Chicago law
has been a dramatic increase in the number of noise complaints from
Chicago's citizens, (See Figure 1.) In 1970 the city government received
approximately 120 noise complaints. During the first six months of 1971
1500 - -
1000 -i -
Noise
Per Six
Month
Period
500--
1970
FIGURE 1. INCREASE IN NOISE COMPJLA1NTS IN
THfi CITY OF CHICAGO
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(before the new law went into effect) the number of complaints rose to
approximately 220. The big increase came in the last half of 1971 "when
noise complaints climbed to over 1, 300--or almost 40% of all the com-
plaints received by the Department of Environmental Control. This
percentage decreased to around 20% of all complaints during the winter
months, reflecting the prevalence of closed windows and the improved
noise reduction afforded by them.
The significance of these statistics (especially the almost 1,500%
increase in complaints over the 1970 base period) is three-fold. First,
they reflect the new stringency of the noise ordinance. Second, they
indicate an expanded public awareness of noise as an environmental pollutant.
Third, and, perhaps, most significantly, they can be directly related to the
well-publicized inauguration of the ordinance and the existence of a single,
known, place to which complaints can be addressed.
Other communities planning to establish an office of noise control
can look forward to a similar increase in complaints if they, like Chicago,
properly publicize their noise-abatement activities.
Table 1 shows a breakdown of noise complaints by noise source.
Relatively more complaints came from affluent neighborhoods than from
poorer ones.
The remainder of this article will focus on the insights that have
emerged from Chicago's first year of experience--insights that may be of
great interest to other cities. The reader is also referred to two abstracts*
on the Chicago experience in the abstract section of the Digest.
No. 08-011, and No. 08-012.
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TABLE 1
COMPLAINT SUMMARY AND BREAKDOWN
FROM
JULY1, 1971 to MARCH 1, 1972
CATEGORIES INVESTIGATIONS MADE
Ice Cream Trucks 13
Buses 3
Trucks 125
Motorcycles 82
Automobiles 80
Air Conditioners 190
Exhaust Fans 97
Chicago Transit Authority 23
Construction 151
Hornblowing 77
Scavengers (privately operated refuse trucks) 142
Musical Instruments 109
Miscellaneous Noises 214
Gas Stations 34
Factory Noises 113
Lawn Mowers 2
Loudspeakers 95
Doorman Whistles 11
Car Washes 9
Church Bells 25
Vibrations 55
Refrigeration Units (Trucks) 8
Dust Collectors 3
Burglar Alarms 7
Airplanes 4
(Subtotal) 1,685
Railroad Noise 60
Total 1,745
Chicago's New Standards
Chicago's present ordinance is the result of new legislation super-
imposed on an older (1957) noise code. The previous code contained a zoning
approach, with limits placed on noise levels at the boundaries separating
various use zones—from heavy manufacturing to residential. It also con-
tained nuisance provisions which served as "catch-alls" for the many unusual
noise sources which exist in a city. These have been retained and modified.
For example, Table 2 shows limits on noise from buildings and installations.
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Cosimo Caccavari, Supervisor of the Noise and Vibration Control
Office, makes a point of particular interest to owners and operators of
factories and buildings with noisy equipment. Sometimes a new source is
turned on that produces noise at the lot boundaries 10-15 dB higher than the
previous background. If complaints started (and most likely, they would),
continued operation would be likely to mobilize opposition to the point where
practically no amount of subsequent noise reduction would satisfactorily reduce
the stream of complaints.
TABLE 2
LIMITS ON NOISE FROM BUILDINGS AND INSTALLATIONS
Type of District
| Limits
Where Measured j (For Monitoring Purposes)
Business & commerical
districts
At boundaries
of the lot
62 dBA
Residential
At boundaries
of the lot
55
Vlanufacturing
--Restricted
Manufacturing
-General
Manufac turing
-Heavy
Manufac turing
At zoning district
boundaries
55 On boundary with a
residential district
62 On boundary with a
business-commercial district
58 On boundary with a
residential district
64 On boundary with a
business commerical district
61 On boundary •with a
residential district
66 On boundary with a
business-commercial district
A new provision of the ordinance requires that manufacturers and
vendors certify that new equipment on sale in Chicago, including vehicles,
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meet noise limits. These limits will become stricter on equipment manu-
factured after certain dates in the future. Limits on present manufactures
are shown in Table 3.
TABLE 3
NOISE LIMITS NOW IN EFFECT ON NEWLY-
MANUFACTURED EQUIPMENT SOLD IN CHICAGO
Motorcycles
Trucks (over 8000 Ibs. gross weight)
Cars & other vehicles
Construction & industrial equipment, including
bulldozers, drills, loaders, power shovels,
cranes, derricks, motor graders, paving
machines, off-highway trucks, ditchers,
trenchers, compactors, scrapers, wagons,
pavement breakers, compressors, and
pneumatic equipment--pile drivers not
included.
Equipment of less than 20 hp for occasional
use in residential areas, including chain saws
pavement breakers, log chippers, powered
hand tools, and the like.
Equipment for repeated use in residential
areas such as lawnmowers, small lawn &
garden tools, riding tractors, &: snow
removal equipment.
Snowmobiles
Dune buggies, all terrain vehicles, go-carts,
mini bikes.
Noise Limit in dBA,
Measured at 50 Ft.
dBA
88
94
74
82
The main thrust of the new ordinance is directed at motor vehicles
and other types of noisy equipment. Thus, the heart of Chicago's noise con-
trol program consists of vigorous enforcement of the older regulations when
a ci.mt:1 lint is made, plus active enforcement of the new operational limits on
motor vehicles.
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Operational limits cm vehicle noise mow in effect .axe measured
at a. distance of 50 feet. They are Eg dBA for trades (or 90 dBA at speeds
over 35 mph), 82 dBA. for motorcycles ($6 dBA at speeds over 35 aaaph}, amd
76 dBA for passenger cars J82 dBA at speeds over 35 mph). Tine limit on
trucks is on total emission including noise from auxiliary equipment such
as refrigeration units. These limits will be ™a«jk» progressively stricter in
the future. (Details on these future limits are given in abstract No. 08-Oil
also in this issue). So far, the over-35 mph limits have not been
enforced, in order to eliminate a variable, tire noise, that might be used by
defendents as an excuse in court.
Program Enforcement
Here is how tine enforcement program works: Chicago's Depart-
ment of Environmental Control is responsible for all types of pollution
problems, including noise. Its fingimeerijag Division and Enforcement
Division cooperate on carrying oat the noise control program. The Enforce-
ment Division has 35 Environmental Control squad cars, radio dispatched,
on the streets on the streets 24 hours a day, seven days a week. Tfoese cars
must respond to all environmental complaints concexniiag air, water, and
solid "waste, as well as noise. Seven inspectors with special responsibility
for noise Tide the squad cars. The members of the Emvorcememl Division
•write citations for all violations except those involving moving vehicles,
"where cooperation of the Chicago Police Department is needed to curb a.
vehicle. Thus, there are two special vehicle enforcement teams which set
up at preselected sites aroumd the city to apprehend violators. The sites
have been selected by fhp Engineering Division to meet SAE measurement
specification; they must afford a free and clear area within a. 1OO foot radius
of the microphone of the noise meter. This condition is hard to meet in an
urban area, axed the Engineering Division had to search hard for eraoogrh
suitable sites. A Chicago police officer, is detailed specifically to -work
with the measurement team. He stands by in a -waiting Environmental Control
squad car and is alerted by radio to curb "flue violator and to issue the citation.
To be sure that they have good court evidence, flue measurement team re-
checks the calibration of the sound level meter immediately after leggiiag the
meter reading.
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Tiber* is a complicatiag factor, namely, the question of who
gets the ticket. When a truck is cited, the issue is, what is more
responsible for due noise, tixe condition of the truck oar the way in -which it
-was operated ? The procedure that has been developed is that the truck
owner usually must post bond to release the truck and its driver.
In an eight month period, 1, 026 traffic citations were issued arad
fines of $7,851 were levied. Tike work of the Enforcement and Engineering
Divisions dovetails. Every complaint must be responded to, Enforcement
bandies most of this caseload. Some complaint, situations are technically
difficult, such as when there are two or more moise sources
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of steps--from building a simple enclosure to relocating the unit--to help
bring older units into compliance. A useful procedure for complex violations,
such as noise from manufacturing plants, is the supervisory program with
phased noise reduction. After being cited, the violator can request a hearing
(there have been79 such hearings in an eight-month period). The Engineering
Division and the violator discuss the problem and alternative methods of
noise reduction, and the violator has from two to four weeks in which to
come up with a proposed noise reduction program. This program can be
designed in phases, starting with the simplest and least expensive reduction
methods, but must lead to compliance within a fixed period. The phases
must be compatible with each other and not go off in different directions.
Thus, if "phase one" does not achieve sufficient reduction, the violator
knows in advance that he must try the next step, and he knows in advance
what the next step will be. If the Engineering Division approves the plan, it
may recommend to the court that the violator's fine be waived and that he be
put into the supervisory program where his progress will be monitored by
the Engineering Division. Several dozen cases are now in the supervisory
program, and about ten cases have successfully passed through it and are
now in compliance.
Continuing Study of Noise Parameters
Within the Engineering Division, the staff specializing in noise
consists of three professionals and three technicians. The annual operating
costs of the entire noise program are running about $250,000 (or under 10
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design stage. Finally, noise specifications are prepared for inclusion in the
specifications for new equipment purchases by other city agencies. It can
be seen that adequate engineering backup is no mere luxury for a city noise
control program, but rather a critical ingredient for its success.
Such preventative measures, which require the scrutiny of engi-
neers experienced in acoustics, are an effective method of achieving noise
reduction over the long term at very low cost. The Department of Environ-
mental Control would like to devote more time to this activity.
Public Awareness
One factor of great help to the success of Chicago's program was
the effort made to get enforcement of the new ordinance off to a flying start.
The two basic ingredients were a thorough publicity campaign before the
ordinance went into force, and vigorous enforcement of the ordinance from
the very first day it was in effect.
Supervisor Caccavari appeared at length on five or six radio talk
shows to answer telephone inquiries. A 60-second public service spot
announcing the new law, and giving a telephone number for further informa-
tion, was run frequently by a local TV station. Day and night telephone
numbers for making complaints were publicized. Inexpensive pamphlets
that explained the law in detail were printed (cost: about $500 for 50, 000).
Ten thousand of these pamphlets were mailed out to local businessmen and
manufacturers and also to selected manufacturers nationwide. One hundred
thousand "SSSHHICAGO, " lapel buttons were distributed.
In the weeks before July 1st, 1972, a complimentary inspection
site was set up which served several purposes: advising motorists who
wanted to learn if their vehicles would be in compliance with the new law,
publicizing the new law, and providing the new noise inspectors with on-the-
job practice. Several motorcycle groups were among the citizens who turned
up to see how loud they were. The cost of various publicity items totaled less
than $10, 000. The existence of a public relations division within the Depart-
ment of Environmental Control was a great aid in the timing and coordination
of this publicity.
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Training the Enforcers
A training program was set up for noise enforcement personnel.
It featured a one-week course on noise and noise enforcement, complete
with instruction manual, prepared by the Engineering Division of the
Department of Environmental Control. This course was presented to 45
attendees, 17 of whom were scheduled for noise field testing work with the
Enforcement Division. Because the new ordinance went into effect in the
summer, when smoke from buildings was less of a problem, several air
pollution personnel in the Department could be transferred to the noise pro-
gram during the first days, thus increasing enforcement impact.
Evaluation
The Chicago ordinance is, enforceable, for the most part. Investi-
gation of some 1800 complaints over an eight-month period revealed about
900 cases where there was a violation, and citations was issued. Of those
citations processed through the courts, convictions were obtained in 85-90%
of the cases.
Since abatement was achieved, in some cases without, resort to
eitationr., and since most offenders involved in court cases eventually came
into compliance, it may be concluded that legal processes led to abatement
in most cases. This contrasts favorably with the situation in New York,
where the Bureau of Noise Abatement, which presently has little legal power,
has relied chiefly on persuasion to secure some degree of abatement in about
30% of the complaints it has handled.
The most successful part of the Chicago enforcement program to
date has been reducing the amount of horn blowing in the "Loop" area of the
city. Horn blowing by taxicabs was a large part, but not all, of the noise
problem there. Cooperation came from the city courts in the form of some
clear-cut decisions accompanied by large fines. The publicity stemming
from these court cases has deterred other potential violaters.
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Effectiveness of the ordinance in reducing noise levels must be
evaluated more cautiously. For one thing, significant reduction of noise
sources will be observed only after a period of time, when the progressively
more stringent noise limits on equipment go into effect and the supervisory
programs, described above, reach successful completion. Presently,
trucking firms find they can usually bring their vehicles into compliance by
improving exhaust systems. Future limits, especially the 1980 standard of
75 dBA for trucks, may be more difficult to meet.
The limitation on sales seems to entail more enforcement pro-
blems. When the ordinance first went into effect in July 1971, only 10
manufacturers or vendors had established communication with the Depart-
ment. There are now 300 on file, although not all of these have yet filed the
required certification. Effectiveness of this program is also threatened by
the sale of unregulated products, close to, but not in Chicago.
The outlook for further limits on noise sources is complicated by
probable Federal preemption. The main argument for Federal regulation
of noise sources is that it would eliminate the possibility of manufacturers
being faced with a "patchwork quilt" of local ordinances differing in measure-
ment techniques as well as numbers. Chicago agrees that Federal regulations
make sense, but points out that even after the legislation giving EPA
authority to set limits is passed it will be several years before those limits
can be promulgated and put into force. Until then, the local limits can fill
the gap in Chicago. Moreover, experience from the Chicago and California
programs will provide valuable data on feasibility and enforceability when
Federal standards are drawn up.
A question as to •whether the City could not do more about aircraft
noise is appropriate since Chicago owns and operates three airports. The
problem is a complicated one. Aircraft in the air or landing and taking off
are under the jurisdiction of the FAA, and beyond local control. This still
leaves the noise from ground run-ups, for which the airport operator is
responsible. The Department of Environmental Control handles this nuisance
like any other--on a complaint basis. So far, there have been few complaints
(Table 2), perhaps indicating that noise from ground run-ups is neglibible
compared to that caused by aircraft in flight. In one sense, aircraft noise
is a secondary problem in Chicago, compared to its impact in communities
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like Inglewood, California. It is estimated that about 15% of Chicago's
population is adversely affected by aircraft liaise, whereas surface trans-
Doxation noise affects neaxly all residents.
The noise control program does not yet regulate total noise at
the boundary of construction sites. Provisions concerning this problem
and also the problem of noise specifications in building codes -were not
included in the 1971 ordinance, because it was felt that additional technical
information was needed. Meanwhile, other measures axe being used for
enforcement. The limits on sales equipment manwfactared aftex January
1972 is one example, although it only applies to equipment sold in Chicago.
Contractors can be cited fox disturbing the peace if they operate equipment
with unrnuffled exhausts. Construction equipment is pxohibited from
operating -within 600 feet of residential buildings between 9:30 P, M, and
'8:00 A.M., except for work on public improvements and the work of public
utilities. Upon request, contractors have changed to quieter equipment and
xe-located noisy equipment. One contractor was required to construct a
partial enclosure around a pile driver.
The private scavenger refuse trucks have been a difficult problem
so fax. They usually meet the noise emissions limits, tout since they
operate mostly at night, their noise is intriusive enough to be annoying.
Another intractable problem is noise from the Chicago Transit
Authority (CTA) system, particularly the elevated portions whose noise
annoys the community as well as passengers. The system can not simply be
shut down, because thousands of citizens depend on it for transportation.
Yet, costs of completely noise-treating it are prohibitive, although the
gradual introduction of quieter rolling stock -will lielp. The new CTA
extensions now being planned will benefit from noise control features
incorporated in the design stage, A private acoustical firm has been hired
to do this work, and the Department of Environmental Control is supplying
survey data.
In a larger sense, the question of effectiveness must ultimately
be defined on the basis of reduction of urban noise to levels consonant with
health. As defined by the World Health Organization, this includes aiot only
the absence of disease, but a positive state of well-being. Hexe, CMcago1®
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noise program can provide only part of the solution: unless noise problems
in areas outside of the city's jurisdiction are systematically reduced at the
same time. These problems include aircraft noise and future urban free-
ways, for which design criteria are to be issued at the national level.
Finally, the ultimate effectiveness of the program will depend on the support
and cooperation of the people of Chicago. A large portion of Chicago's
program depends on the complaint as the point at which investigation and
enforcement are initiated, so the minimum requirement for the success of
the program is a citizenry concerned enough to pick up the phone -when
necessary. As the statistics show, a successful public awareness compaigni
can do much to foster citizen concern.
In conclusion, Chicago's experience suggests several points to be
considered by other cities contemplating noise control programs of their own:
o Enforcement in Chicago's main area of emphasis--vehicle
noise--can be effective, but the true impact of the program
will not be felt until the more stringent limits scheduled for
the future go into effect.
o Start-up costs cd a noise program are now somewhat
reduced for other cities, because preliminary studies
done by Chicago, Boston, and several other cities are
available. Chicago's preliminary study cost $54,000;
much of its findings are applicable to the problems of
other cities.* However, other initial costs must be
considered: preliminary noise survey, purchase of
measuring instruments 'Chicago's cost $30,000,
including a mobile measurement van), training costs,
and hiring an acoustical consultant.
o The hearirg process for proposed legislation is crucial.
It is a good idea to hire an acoustical consultant with
outstanding credentials to be an expert witness, explain
technical points, and assist in writing amendments. Key
groups who will be affected by the legislation should be
urged to appear at the hearings. An effort should be made
to canvass members of the industrial community, because
it is often possible to find industrial spokesmen sympathetic
to the legislation who can be asked to testify.
A copy of this study is available at $15. 00 from the Department of
Environmental Control, 320 N. Clark Street, Chicago, Illinois 60610.
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The enforcement staff must have at least some engineering
back-up if the program is to be a success. It is indispensible
for such duties as measurements in complicated situations,
training others, testimony in court, helping those cited with
violations achieve compliance, reviewing building plans to
pinpoint and prevent future noise violations at the design
stage, and designing a measurement program to evaluate
program effectiveness,
A noise control program is strengthened when it can draw
on the larger resources of a comprehensive city department
for environmental affairs.
The most important single factor to the success of the
enforcement of a new noise control law is having trained,
practiced enforcement officers ready to begin operations
from the first day that the new law is in force.
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NEW NOISE INFORMATION RETRIEVAL SYSTEM NOW ON LINE
In late June the Environmental Protection Agency launched a new
information system dedicated to noise abatement and control. It is scheduled
to be fully operational as early as mid-July. This system, designed for
future growth, will contain, initially, approximately one thousand citations
and abstracts of various publications. It has been estimated that, ultimately,
this data base may exceed 50, 000 citations. The abstracts in this pilot issue
are representative of the information available from this system. In fact, if
future issues of this Digest are to be forthcoming, they will be generated as
a by-product of this information system.
The data contained in this new system are directly accessible from
a remote terminal. The Office of Noise Abatement and Control anticipates
that the data base contained in this system will ultimately be, transferred to an
EPA-wide system which provides for terminal access from over twenty stations
throughout the United States. The capability exists to add further access
terminals including overseas locations linked through satellite communications.
For the time beinj,, only recent publications are included in the
data base, i.e., publications issued no earlier than 1969. The bulk of the
coverage emphasizes current materiel including such items as witness
statements given at the EPA Noise Hearings, Environmental Impact Statements,
items from the current periodical publications, proceedings of conferences,
government contractor reports, as well as special locally oriented reports.
The EPA, in its Report to Congress, showed that the rest of the
world has developed a wealth of practical information on noise abatement and
control. Therefore, a particular effort has been made to include, in English,
the best of this information.
All abstracts are indexed in depth. The index terms contained in
this publication reflect only a small fraction of the terms residing in the
system. Thus, it is possible to specify a query at a very fine level of detail.
Eventually, a comprehensive thesaurus will be developed which should aid the
user in formulating his question.
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To use the system, full Boolean logic may be applied. Thus, the
user can connect his search terms with "and", "or", "not," &: "and/or" links.
He can also specify geographical areas of interest as well as author, corporate
source and other elements of the bibliographic citation. A search formulation
might appear as follows:
TRUCKS, or DIESEL ENGINES, and or
MUFFLERS, TRUCK, and (REGULATION,
or LEGISLATION), and or ENFORCEMENT,
not CALIFORNIA
Such a query should provide informative abstracts on enforcement
of truck noise regulations in states other than California. Once this query
has been keyed and a transmit button has been pressed, the system -will
respond within a few seconds with an indication of the number of "hits, " i. e. ,
the number of abstracts available against such a query formulation. If the
number of "hits" is either greater or smaller than desired, the query should
be reformulated until the number of "hits" is approximately equal to that
desired. A command can then be given which will produce the citations and
abstracts in typed form --or displayed on a cathode ray tube depending on the
type of terminal utilized. An alternate lower cost response can be provided
if an over-night batch process is requested in lieu of the conversational mode
response.
Initially, this system will facilitate ONAC's responses to inquiries.
Ultimately, multiple users will interrogate the system simultaneously. Other
files, equally accessible, will contain records on on-going research pending
and completed litigation and enforcement experience as well as other related
information.
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ABSTRACTS
EPA HEARINGS
The following pages contain abstracts of selected witness statements
at the EPA hearings on the problem of noise pollution. These public hearings
were conducted in 1970 by the Office of Noise Abatement and Control in
response to a mandate given by Congress in Title IV of PL-91-604, signed
into law in December 1970 by President Nixon. Most of the witnesses ai,
the hearing in a particular city spoke on a common theme topic. The cities
in which the hearings -were held, and the theme topics for each city, were
as follows:
Atlanta, GA Noise in construction.
Chicago, IL Manufacturing and transportation noise .
Dallas, TX Urban planning and noise.
Architectural design and noise.
Noise in the home.
San Francisco, CA Standards, measurement methods .
Legislation and enforcement problems.
Denver, CO Agricultural and recreational noise.
New York, NY Transportation, urban noise and social
behavior.
Boston, MA Physiological and psychological effects.
Washington, DC Technology and economics of noise control.
National programs and the relations with state
and local programs.
In the following pages, the abstracts are arranged by the cities in
which the hearings were held.
Full transcripts of all of the -witness statements, published by the
EPA for each hearing, are available from Supt. of Documents, U. S. Govern-
ment Printing Office, Washington, D. C. , Zip 20402. For a list of all witnesses
and their organizations, the reader is referred to Appendix C of the Report
to the President and Congress on Noise (also available from USGPO: SN 5500-
0040, 1972, $1.75).
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00-001
HEARINGS
00-001
Hasten, J.
Bergsten, L.
CaterpiIlar Tractor Company,
Peoria, I L
On: NOISE SUPPRESSION PROGRAM IN THE TRACTOR
INDUSTRY
Witness Sfatement
Public Hearings on ftoise Abatement and Control-
Atlanta, !UL 8, T97!
The problems encountered in attempting to equip
or modify a tractor to meefr the operator noise
exposure standards of the Walsh-Hea-ley Act are
presented. Over 10,000 engineering design
hours and 4000 roan-fiours were requ i red to
produce a single serr of prototype par^s which
formed a noise suppression1 package for one
tractor model. This package nedaced the level
of noise at the operator's station from 96.5
ofiA to 89.5 dBA. According to the Welsh-Healey
cumulative exposure formula, the total time an
operator could be permitted to run the machine
fn an 8-hour day was 2.9 hours. The only way to
meet the Walsh-Healey criteria without
requiring the use at protective devices is ta
enclose the operator in an acoustical Iy treated'
cab. The heavy structural elements of roll-
over protective structures (RQPS), required
under the Occupational Health and Safety Act as
a necessary part of such cabs, make the noise
suppression problem all the more difficult,
since These are excellent transmitters of
noise. The following recommendations are
presented:
1) !~he EPA should not promulgate additional
standards fair the protection of aperaTors
untiI it is shown that the regu t at i ons of the
Walsh-Healey Act of 7969 and ttie Occupational
Safety and Health Act of 5970 can be met.
2) Research should be initiated to acquire and
analyze relevant spectator noise data, to the
and that realistic and attainable spectator
noise level criteria can be established.
3) When the research has been completed, the
EPA ahoLld establish uniform spectator noise
level regulations which wil! be applicable
nationwide.
4) Hoi-form test procedures should be
estabt ished for the measurement of both
spectator and operator noise levels once
standards have been established. These
procedures should be representative and
reproducible. A single Federal agency snould
be responsible for both the prossulgatFan and
enforcement of all noise regulations.
5) Due to the difficulty of retrofitting noise
suppression packages on construction equipment
currently in the field, if any retrofit
standards are set, they should be less
restrictive than new product standards.
6) It is strongly recommended that regulations
with respect to spectator noise level criteria
for construct i on mach i nery ncrt be app lied pri or
to 1974. In a discussion which followed, the
additional cost of developing new machines and
retrofitting older models was considered. In
the final analysis, the increased cost would
ultimately be reflected in the product.
00-002
Jackson, E. l.
QeIta P. Incorporated
On: CONTROL OF NOISE WITHIN THE CONSTRUCTION!
INDUSTRY
Witness Statement
Public Hearings on Moise Abatement and Control
Atlanta, JUL 8, 1971
A discussion of state of the art for noise
control in construction equipment is presented
and recommendations are made for the
implementation of existing methods and devices
for noise abatement. It is acknowledged that
si leocfrrg packages have been developed and are
available for construction equipment. There
is strI I much work to be done in the field of
noise control, but it- is also necessary to
minimize the economic impact" on the
construction industry. Technical breakthroughs
are not the major requirement. The problem is
to get these standard silencing techniques
introduced universally into the construction
industry.
The basic problem of noise control is
economic. Performance is ncrr improved in
equipment or machines when silencing is added.
Costs varying from I to tO£ are typically
addsd to the equipment and Fn some cases
operating costs are increased. Various studies
have tried to prove that reduction of
Workman's Compensation, for example, would more
than offset the cost of silencing, but
management is not convinced. There is now no
economic incentive to the construction
industry; in fact, there is a penalty.
However, there are benefits for the industry
through improved performance, (ess damage to
health through hearing loss, increased
productivity and easier and clearer
comnun i cat i orv.
The following recommendations are presented:
Additional legislation with technical meaning
in quantitative terms and enforceable language
is needed. The economic realities of the
situation must be understood. Subsidies and
economic incentives snould" te considered during
the transition period. Analysis and research
18
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00-003
EPA HEARINGS
into the problem are also needed to better
identify and solve these problems with specific
emphasis on how new concepts could lead to
quieter and better equipment.
total of $362 million annually, for a reduction
of 5 to 12 dBA. A cost of $200 to $2000 for
parts plus the cost of installation is
estimated for the equipping of existing
vehicles.
00-003
Cod I in, J. B.
Al I is Chalmers Corp.,
Springfield, I L
On: TECHNICAL ASPECTS OF SOUND CONTROL
Witness Statement
Public Hearings on Noise Abatement and Control
Atlanta, JUL 8, 1971
00-004
Walk, F. H.
Walk, Haydel and Associates, Ltd.,
New Orleans, LA
On: NOISE IN CONSTRUCTION OF INDUSTRIAL PLANTS
Witness Statement
Public Hearings on Noise Abatement and Control
Atlanta, JUL 8, 1971
In this discussion of the problems of noise
control in the manufacture of construction
equipment, emphasis is placed on the cost of
these improvements to industry and eventually
to the taxpayer. It is estimated that 562,000
pieces of equipment are in operation and that
they generate $8 billion worth of construction
annuaIly.
The Construction Industry Manufacturers
Association (CIMA) has cooperated in the
development of measurement and control of
noise. Included in the study were noise
measurement at operator's station, noise
measurement at 50 ft radius, construction job
site noise measurement, and cumulative operator
noise exposure measurement along with
standardized reporting methods.
Experiments on both short-term and long-term
methods for sound control are discussed.
Short term methods include mufflers, enclosing
engine, hood and covers lined with sound
deadening materials. Many of these are not
durable, and when many sound deadening
materials become oil-soaked they are inflamable
which creates a definite fire hazard. It is
necessary to weigh the tradeoffs in
serviceability, effect on reliability, safety
and cost.
Engineers are working on a long-range basis on
components such as engines, hydraulic pumps,
gearing of transmissions and piping to
determine what can be done at the source to
control noise. To date, success has been
marginal. The cost implications are high.
Machines have been analyzed component by
component, and most will require redesign and
retooling. Estimates indicate that noise level
reduction will be 3-6 dBA at 50 feet. The cost
impact is estimated to be 10 to 25% per
vehicle. The estimated long-range cost to the
public is $202 million annually. This, in
addition to the short-range program costs is a
A discussion of problems in reducing noise
levels in the construction industry is
presented.
Although much progress has been made in the
isolation and reduction of plant operating
noise, far less progress has been made toward
noise abatement in the construction industry.
The average industrial plant construction
manager has been subjected to much less noise
abatement pressure than the average industrial
plant operator. This is probably due to the
temporary nature of construction operation as
opposed to a long-term, permanent manufacturing
operation.
An improvement in the state of the art of noise
abatement in construction can be realized if
permissible standards of sound levels are
assigned to specific items of construction
equipment. Manufacturers should be required
to prepare sound pressure levels on a uniform
basis for all types of equipment. For each
type, operating conditions, distance-
measurement criteria, and directionality
characteristics must be developed under
controlled environment. If noise abatement
programs are accelerated, careful attention
must be given to the establishment of
reasonable standards for the industry and also
to the planning of a timetable for stepwise
enforcement so that the costs of compliance do
not become excessive and further deter capital
expansion programs of industry. A discussion
followed on the relative cost of developing and
jsing improved equipment and it was concluded
that it would be In the order of magnitude of
1C to 10?.
19
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00-005
EPA HEARINGS
00-005
Watts, J. A.
Michigan University, Ann Arbor
University of Michigan Law School
On: VEHICULAR NOISE CONTROL LEGISLATION
Witness Statement
Public Hearings on Noise Abatement and Control
Chicago, JUL 29, 1971
A noise control project with participation by
the University of Michigan's Environmental Law
Society and Department of Mechanical
Engineering is designed to develop enforceable
noise control legislation for various
governmental bodies. It is primarily concerned
with vehicular noise.
Local and state police and highway officials
were interviewed. It is concluded that the
most important aspect of noise pollution
legislation is the problem of enforcement.
Enforcement of noise control legislation is
expensive. It requires special equipment and
training. Enforcement may be extremely
difficult. Weather changes affect measurement.
Certification and calibration of instruments
may be extremely time-consuming. The police
want simple, reliable and inexpensive
instruments which can be operated under varying
conditions. Until this equipment is available,
one solution may be to employ noise teams
composed of a police officer and a person
trained in noise measurement techniques.
Definite legislative standards are necessary
to avoid the problems created by the present
statutes which prohibit "excessive and unusual
noise".
An effective solution to the noise pollution
problem is effective enforcement of
manufacturing standards. There is little
evidence that manufacturers will reduce noise
levels without government enforced standards.
The following recommendations are presented:
Federal standards for vehicular noise should
be established at the earliest possible date.
Provisions should be included which allow for
stricter state standards.
Full matching grants should be made available
to police and health departments throu"k-''-
the nation ^o < un-hase equipment and train
personnel in noise control.
A system of tax incentives for the manufacture
of quiet products should be employed to
ascertain its feasibility.
The long-term goal in the fight against noise
pollution should always be to reduce the noise
level and not merely to hold the line at an
"acceptable" noise level. And the last
recommendation, additional Federal highway
funds might be supplied for research on the
use of material for quieter road surfaces.
00-006
Lew is, E.
Northwestern Students For A Better Environment
On: NOISE POLLUTION AND EDUCATION
Witness Statement
Public Hearings on Noise Abatement and Control
Chicago, JUL 29, 1971
This statement, made by Northwestern Students
For a Better Environment (NSBE), is based on
information presented in Volume I and in
preliminary drafts to Volume I I of a study
entitled "Comprehensive Plan for the North
Lakeview Section of the Uptown Model Cities
Area" (of Chicago).
This study, financed by grants from the Sloan
Foundation and the National Science Foundation,
was undertaken by students working through the
Urban Systems Engineering Center and the
Design and Development Center, both at
Northwestern University.
Noise Pollution in North Lakeview affects many
patterns of human existence. But, its effects
on safety and education are the most
d i sturb i ng.
It was observed that children could not hear
approachingg cars and that noise from the
elevated trains of the Chicago Transit
Authority (CTA) frightened them. A more
serious noise pollution problem with many
unknown effects is disruption of classrooms.
The following recommendations are made about
the level of noise generated in one Chicago
community area:
The Walsh-Healey Act should be amended so
workers are better protected from hazardous
noise levels. NSBE recommends the adoption
of 80 dBA, as proposed by the New York State
Quiet Communities Program, as a maximum level
for prolonged periods.
Second, EPA should adopt Sound Transmission
Class levels. The STC level is the level of
sound which building materials baffle. EPA
should adopt STC levels for building materials
that will reduce noise levels below the 80 dBA
level.
20
t
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00-007
EPA HEARINGS
Third, EPA should perform additional research
on the effectiveness of baffles and concrete
supports which are used for noise abatement
around CTA tracks.
Finally, a new friction reducing compound
should be developed. This compound will help
reduce noise resulting from rail-wheel
interaction on the elevated tracks. A
demonstration grant from the Federal government
may lead to an inexpensive means of reducing
decibel levels.
00-008
Spahr, H.
Park Ridge, IL
On: AIR, NOISE, MEASUREMENTS AND PROCEDURES
Witness Statement
Public Hearings on Noise Abatement and Control
Chicago, JUL 29, 1971
00-007
Corbett, J. J.
Airport Operations Council
International, Washington, DC
1700 K Street, NW, 20006
On: AIRCRAFT NOISE POLLUTION AS A NATIONAL
PROBLEM
Witness Statement
Public Hearings on Noise Abatement and Control
Chicago, JUL 28, 1971
Aircraft Noise pollution is viewed by
governmental airport operators as the single
greatest constraint to orderly aviation
development in the 1970's. New airport
capacity is stalled across the nation and
around the globe primarily because of
understandable community and public
disaffection with the noise of current day
aircraft. The single most beneficial step
offering promise of noise alleviation is
accelerated Federal applied research toward,
and a prompt Federal decision regarding, the
retrofit of the existing jet fleet, primarily
for those aircraft whose useful service life
exceeds 5 years. The international and
interstate nature of air transportation
requires that action to mitigate aircraft noise
be concentrated on reduction of noise at its
source, the aircraft engine, and that Federal
or international action, and not inconsistent
state/local measures, be expedited.
The City of Park Ridge has been monitoring
aircraft flights originating from O'Hare
International Airport flying over the
community since 1963. In light of this, Park
Ridge adopted an ordinance which essentially
provides that flights over portions of the
city causing noise in excess of 95 dBC are a
nuisance.
To implement the provisions of the ordinance,
a bubble top truck equipped with a sound
measuring device and a radio capable of
monitoring air traffic was obtained and was
designed so that visual observation of flying
aircraft could be made conveniently.
The sound truck and equipment is generally
operated by a member of the Park Ridge Police
Department who has received specific training
in the use of the equipment.
A consulting acoustical engineer has evaluated
the noise measuring program and has determined
that the measurement techniques of Park Ridge
officials are sufficiently good.
Complaints appear completely justified since
levels which evoke complaints are equal to or
in excess of the 85 dBA 'critical' or 'danger'
level.
A simple, easily demonstrated case can be made
to show that present aircraft operations at
O'Hare already expose community areas to
dangerous noise levels and that the proposed
plans for additional runways at O'Hare will
increase the exposure levels and the affected
geoographicaI area.
The schools of Park Ridge find the
inconsistency and high level of noise pollution
attributable to the expansion and lack of
pattern control at O'Hare International Airport
becoming increasingly less tolerant in the
educational setting. In general, it was
determined that modification in the teachers'
approach to instruction are necessary.
Particularly where a combination of verbal and
auditory faculties are needed, the teacher is
forced either to shout or, by preference, to
discontinue communication until the noise
subsides. Valuable instructional time is lost
and crucial learning activities are set adrift
as concentration is broken and young minds
wander to the source.
21
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00-009
EPA HEARINGS
00-009
Rupert, H. M.
Federal Highway Administration,
Washington, DC
Zip 20591
On: CONTROL OF HIGHWAY RELATED NOISE
Witness Statement
Public Hearings on Noise Abatement and Control
Chicago, JUL 28, 1971
The highway related noise problem and some
potential solutions are presented. The control
of this nuisance requires the concerted and
coordinated efforts of many programs, agencies,
firms and individuals.
There is good reason to believe that quieter
vehicles can be manufactured. If the
manufacturing industry were furnished
reasonable noise criteria which would be
uniformly applied to all manufacturers,
improvement could be obtained without
jeopardizing the sales and profits of any
indivi dual fi rm.
The President has recommended Federal
legislation which would enable this control.
A bill has been introduced in Congress to
provide this authority to the Environmental
Protection Agency.
If the manufacture of quieter vehicles were
required, there is no assurance that they would
remain quiet. Most State motor vehicle codes
require that a vehicle not be operated without
a muffler or in a manner which creates loud
or excessive noise. The determination of what
is loud or excessive requires a subjective
determination on the part of an enforcement
official. As a result, enforcement is
difficult and ineffective. The Federal Highway
Administration recommends State and local
enactment and enforcement of numerical noise
level Iimits.
Reduction of the noise which the vehicle
creates will not eliminate all highway related
noise problems. An amphitheater should not be
constructed near an airport or adjacent to a
heavily travelled freeway. The same is true of
some types of single family residences, some
types of schools, hospitals and many other
types of land use.
Land use control in areas where noise is a
problem should be considered. The lands need
not necessarily remain vacant. Most
commercial and industrial activities can be
made to conform to a noise environment.
Sometimes the local officials who control land
use, planning, and zoning are not aware of the
potential noise in these situations.
Transportation officials must continue to
cooperate with local officials, informing them
of potential areas of incompatibility, and
helping to plan compatible activities. In
addition, a national land use policy, with
built in incentives to localities is needed
to insure compatible land use development.
The Congress has directed the undertaking of
some enormous tasks with the enactment of the
Federal-aid Highway Act of 1970. One of these
tasks is the development of guidelines to
assure that adequate consideration is given to
the social, economic and environmental effects
in the Federal-aid highway program. One of the
specific effects the Congress wanted included
is noise.
There is great potential in the guidelines and
standards efforts for further increasing the
highway program's responsiveness to the
current concern for the environment. However,
great care must be taken to be certain that
they are not so severe as to cause a serious
impediment to the highway program.
The noise guidelines are expected to be a
procedure for analysis of noise impacts.
Included in the analysis would be:
(a) determination of existing noise levels,
(b) inventory of noise sensitive land uses
or activities, (c) prediction of anticipated
noise levels from the proposed highway project,
and (d) study of noise abatement alternatives.
The results of the analysis would be furnished
to the decision maker together with the
analyses of other social, economic, and
environmental effects to provide a more
comprehensive basis for making highway
deci sions.
The noise standards are expected to be
numerical noise levels (in decibels using the
A-weighted scale) for various land uses and
activities. There will be different values
for day and night, and there will be both
average and peak noise levels.
There are several opportunities available for
control of noise during the development of a
highway project. During the location studies,
the potential noise impact of each alternative
alignment can be determined. From a noise
standpoint, the alignment having the least
noise impact should be selected.
The design of a highway offers additional
opportunities to control highway related noise.
The advantages of a depressed roadway can be
considered. The same noise level reduction
can be obtained by construction a noise barrier
at much less cost.
Landscape plantings are an aesthetic asset to
almost any highway setting. Some noise
reduction can be obtained by avoiding steep
roadway grades and by holding their length
to a mini mum.
New acoustic materials are needed for highway
work. They must be durable, attractive,
economical and easily cleaned. Truck exhaust
22
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00-010
EPA HEARINGS
stacks must be gotten closer to the ground so
that low barriers will be more effective.
Pavement surfaces must be developed that are
both quiet and safe.
A last resort capability is needed which could
be used when all other techniques are
inadequate or uneconomical. Possible
approaches might include authority to purchase
noise easements or noise rights, the outright
purchase of a property, or installation of
noise insulation.
00-010
Ringham, R. F.
Staadt, R. L.
International Harvester Company,
Chicago, IL
Chicago, IL
On: HIGHWAY TRANSPORTATION NOISE
Witness Statement
Public Hearings on Noise Abatement and Control
Chicago, JUL 28, 1971
Typical truck noise and its sources and
measures involved in controlling it are
reviewed. The overall approach to legislative
control of highway vehicle noise is also
discussed. Criteria for regulations must
reflect test conditions and procedures
specified for verification of compliance.
Vehicles which contribute the most to highway
noise are the large diesel powered trucks.
Several noise sources are inherent in these
units: exhause noise, cooling fan, engine air
intake, engine mechanical and combustion, and
tire and wind noise.
If certain sound sources are eliminated; for
example, the 84 dBA exhaust noise by a
theoretically perfect muffler, the total noise
level would only drop to 86 dBA. Similarly,
if other single sources are eliminated, only a
slight drop in overall noise is realized.
Since exhaust noise cannot be eliminated
completely, the only approach which can reduce
overall levels is to lower all sources which
individually approach the level of the total.
Such an approach was taken in the case of the
88 dBA vehicle.
2) A larger, more efficient muffler reduced
exhaust noise.
3) The air intake noise was reduced by an
improved silencer relocated from the side of
the hood to the front to direct sound away
from observers.
4) Shields around the engine compartment now
block engine radiated mechanical and
combustion noise.
The resulting overall noise level is now 86
dBA. It is noted that most of these
modifications required considerable redesign
thereby making retrofitting extremely expensive
i f not impossible.
The value of 86 dBA is considered to be the next
plateau in heavy truck noise control. Major
cooling fan development programs and further
engine shielding will be required to meet this
level. To get below 86 dBA will involve
extensive programs in engine and cooling
system redesign and development. This will
involve several years and can reflect
considerable increase in cost to the user.
Regulations or sound limits for the vehicle
user should not be lower than those required
of the manufacturer or user at the time the
vehicle was built. The operator, or
manufacturer, for that matter, has no means
of making the vehicle quieter than it was
when originally built. As shown earlier,
significant sound reductions by retrofit
programs generally are not practical.
Regulations cannot be effective without proper
enforcement. Enforcement personnel must be
trained in noise surveillance and operate at
the carefully selected sites which are
required for accurate readings.
00-011
Walker, B.
Cleveland, Ohio
On: PREREQUISITES FOR NOISE CONTROL
REGULATIONS
Witness Statement
Public Hearings on Noise Abatement and Control
Dal las, AUG 19, 1971
The measures employed were:
1) The cooling fan was run at a slower speed to
reduce fan noise and radiator size increased to
offset the loss in cooling air flow.
An environmental health commissioner discusses
the sources of residential noise and
requirements of an effective noise control
program.
23
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00-012
EPA HEARINGS
In contrast to older dwellings, the modern
dwelling with its light weight construction,
open plan design and multitude of noise makers
provides very little protection from noise
generated within or intruding from the outside.
Data from a survey conducted in Cleveland
indicated that 8055 of the 1000 respondents
were disturbed by noise outside the building
and 16$ by noise from adjoining apartments.
Zoning ordinances are of limited value in
controlling urban noise, as they simply
aggregate similar land use activities, as
residential, commercial and industrial, and
tend to ignore peripheral areas and factors
such as transportation. These are reasonable
grounds on which to question the adequacy of
local government, left to its own resources,
to control urban noise effectively.
The alleviation of the noise problem frequently
requires action that transcends political
boundaries. A broad-based, coordinated attack
on the problem must involve the Federal and
state levels of government. It is practical
and highly desirable to establish Federal
standards for some items moving in interstate
commerce to eliminate noise producing features
at the point of origin or at the point of
manufacture rather than expect local control
once the equipment is operating in a community.
The critical areas of continuing research,
manpower, training and development criteria,
demonstrations and funds for local surveillance
and monitoring require the full and effective
leadership of the Federal government.
There are shortcomings in our present knowledge
and programs for noise control, and if we are
to minimize additional environmental stresses
on community living, a coordinated attack on
the problem must be developed now. It is
essential that nationally accepred techniques
be developed for the measurement, evaluation
and rating of noise and its effect on human
health, and to accomplish this will require
scientific talent, trained technicians and
additional facilities and financial resources
at all levels of government.
Examples of ignorance of architects and
building mechanics in construction techniques
to reduce sound transmission are presented.
Some suggestion for activities of EPA in this
field are out Ii ned.
A new hi-rise apartment was advertised as
having "revolutionary soundproofing." In
reality the noise was worse than some old
tenement houses. The load bearing walls had
a 62 STC rating but the others were on 35 STC
and poorly designed.
In another case, a hospital, the penthouse
machinery was not properly isolated. After
four years professional help was sought and the
problem corrected very easily.
Another example is post-tensioned concrete.
Using this method of construction, floors can
be thin and supports far apart. The buildings
vibrated violently. Everyone blamed someone
else. It was eventually corrected, but much
time and money was wasted.
Two practical methods to both lower cost and
noise are presented. The first entails
eliminating wood floor and placing carpeting
over the slab. The second is changing from a
lead oakem joint in the waste pipe system to
a neoprene gasket.
EPA could disseminate available information on
architectural design on isolation. Simple
consumer bulletins could be sent that would
help in consumer understanding. The EPA should
act as a clearing house for new products that
will help build quieter houses, such as the
neoprene gasket. Some EPA media is needed
through which home-builders could be reached,
since they are the environment builders. If
the builders could be reached through some
simplified type of do-don't corrective
mechanisms, they could be put into effect very
quickly. Time is a great concern.
00-012
Spano, B.
Polysonics Acoustical Engineers,
Washington, DC
On: THE STATE OF THE ART, HOME NOISE
Witness Statement
Public Hearings on Noise Abatement and Control
Dal las, AUG 19, 1971
00-013
Wegner, R. L.
North Texas CounciI of Governments
On: REGIONAL AIRPORT PLANNING
Witness Stafement
Public Hearings on Noise Abatement and Control
Dal las, AUG 19, 1971
The efforts of a regional organization, the
North Central Texas Council of Governments
(NCTCOG) to help local governments deal
effectively with the challenges and
opportunities posed by the new Dallas/Fort
24
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00-014
EPA HEARINGS
Worth Regional Airport are discussed. This
airport will have the capacity to accommodate
300 aircraft movements per peak hour.
The Regional Airport Environs study stressed
the impact of aircraft sound on the development
of surrounding land. An aircraft sound
exposure map was prepared. A brief simple
explanation of the significance of the sound
zones depicted on that map was prepared for use
by local officials concerned with land
development in the areas immediately adjacent
to the Regional Airport site.
Several seminars were held for planners,
administrators, building inspectors, and
representatives of school districts, which
gave technical facts and guidance, recommended
land uses and information about acoustical
treatment of buildings.
Another project, funded by the Department of
Housing and Urban Development and entitled the
"Cooperative Program of Planning for Airport
Impact," was designed to help the cities most
directly affected by the new airport to carry
on local planning in response to airport
impact. The city of Irving developed an
Airport Zoning Ordinance and soundproofing
modifications to its building code. The
soundproofing modifications will add 2 to 10?
to the cost of a building.
Another project of NCTCOG is the Cooperative
Planning Program, in which a number of model
codes and ordinances and guidelines are being
prepared to aid local governments in improving
their local planning capability.
It is suggested that both preventive and
remedial measures to control, reduce and/or
eliminate the harmful effects of noise become
the concern of all professional planners and
official planning agencies. To plan
preventive and remedial measures planners and
planning agencies require legal authority,
political sanction, technical and financial
assistance. Federal legislation should make
provisions for technical training and
financial assistance and incentives for noise
control and abatement planning at state,
regional and local levels as part of the
environmental protective activities at each of
these levels. Approximately $6,000,000 per
year would provide an average of $25,000 to
each of the 240 standard metropolitan areas.
Assured funding of this type would establish
a sound foundation and a start toward
deliberate, continuing environmental protection
activity at the regional level.
00-014
Hixon, E.
Texas University,
Austi n
On: NOISE ISOLATION IN LOW COST HOUSING
Witness Statement
Public Hearings on Noise Abatement and Control
Dal las, AUG 19, 1971
In 1968, 10 single family, low-cost dwellings
were constructed in Austin, Texas, under the
sponsorship of the U.S. Department of Housing
and Urban Development. The purpose was to
develop and test architectural design,
building materials and construction methods.
The University of Texas was asked to provide
architectural, engineering, psychological and
sociological evaluations of these houses.
Noise isolation studies were conducted as part
of the engineering evaluation.
Standard FHA specifications were waived to
allow innovations. Ten plans utilizing a wide
range of materials and construction methods
were chosen. Most of the acoustic tests were
made after the houses were occupied by the
purchaser. Test results for 6 of the houses
indicate generally low values of noise isolation
and lack of consideration for noise isolation.
In some cases simple changes that would add
little to the cost could have resulted in
large improvements. It is concluded that
noise isolation should be a major consideration
in housing for low-income families who have
the greatest need to enhance the quality of
I ife.
00-015
Parrott, C. D.
Redevelopment Authority
La Crosse, Wl
On: THE RESPONSIBILITY OF THE URBAN PLANNER
FOR NOISE CONTROL
Witness Statement
Public Hearings on Noise Abatement and Control
Dal las, AUG 19, 1971
The selected placement of potential major
noise producing activities to protect the
urban dweller and his neighborhood environment
is discussed. Regulatory measures governing
intensity of land use, control limits on sound
25
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00-016
EPA HEARINGS
producing devices, and sound reduction
engineering and architectural designs for
transportation facilities and certain other
forms of land use are required to supplement
selective placement. With the systematic
application of these controlling factors and
the public's understanding of the need for
such measures, the mounting threat of sound
pollution can be reduced. The urban planner
is In a unique position to help educate the
public and the elected and appointed officials
he serves.
The City of Madison, Wl, has adopted a code
setting maximum noise levels for all
stationary and moving noise-producing devices
in all zoning districts and public ways with
the only apparent exceptions being emergency
vehicles and fireworks displays.
Transportation planners should not be preparing
plans for communities which call for the
construction of high-speed freeways and
expressways in association with residential
land use. Any freeway network in an urban area
may pass through commercial, industrial,
residential, agricultural and other types of
land use areas. Although normal noise levels
from freeway sources may be acceptable in an
industrial area, these same levels would be
less acceptable in a residential area. From
the economic standpoint, it is difficult to
justify the costs of purchasing additional
widths of right-of-way to protect residents
from the adverse effects on high speed freeway
facilities at this point in time.
People generally have little or no knowledge
of the possible effects that various types of
installations can have on their environment
until the conditions are experienced, and then
it is too late. Therefore, it is important
that the planning profession be sufficiently
informed on all environmental considerations
and take these factors into account in their
studies, in their reports, and in their
explanations to the public officials.
Land use controls, density controls, public
property acquisition, and building code
soundproofing requirements for construction
in undeveloped areas near freeways and
airports can employ limited defensive
measures against excessive sound. The problem
near transportation facilities already
surrounded by urban development is
significantly more complicated. Preventive
measures, however unpopular, are far less
costly and difficult than corrective actions.
The requirements for moving traffic and
aircraft will be greater in 1990 and the year
2000 than they are today; but, also, it must be
acknowledged that the requirements for
preserving our environment will also be much
greater than they are now. Somewhere we must
turn the corner and make planning for the
integrity of our natural environmental
resources and the people they serve and protect
as commonplace as the planning for residential.
Industrial and commercial areas and
transportation facilities.
00-016
Tanner, C.
Hydrospace Research Corporation,
San Diego, CA
On: MEASURING TECHNIQUES FOR NOISE STANDARDS
Witness Statement
Public Hearings on Noise Abatement and Control
San Francisco, SEPT 29, 1971
This discussion deals with the measurement
techniques for use in certain airport noise
standards. These techniques are based on the
measurement and processing of noise signals to
define the 3 basic properties of noise:
1. Absolute level
2. Frequency content
3. Time variations
The resultant measurements are used in a
variety of computational procedures to assess
not only the basic nature of the sound signal,
such as defining a pure tone component, but to
evaluate the subjective annoyance of a sound
by calculating effective perceived noise level
or noise exposure levels.
Each noise standard sets down some rather
detailed specifications regarding:
1. The instrumentation that can be used,
2. Calibration measurements,
3. Physical location of microphones,
4. Operating limitations, and
5, Signal processing and computational
requi rements.
Measurement requirements for the Federal
Aviation Regulation Part 36 which specifies
the effective perceived noise levels of
commercial aircraft, require microphones at 3
sides and the measurement of the noise of at
least 6 take-offs and 6 landings. These
measurements are processed to define the
frequency distribution and energy level every
one-half second. These values are corrected
and used to compute perceived noise levels
which are compared with the allowable limits.
The measurements for the California Noise
Standards require that at large airports
microphones are located at 12 sides and
measure the noise above a specified threshold
from every operation. Using an updated
summation for specified time periods of the
day, the composite noise equipment level is
computed. This level is compared with
previously established levels around the
a Irport.
Although there are a number of measurement
techniques that are used in implementing noise
standards, all are subject to outside
Influences which must be recognized in order to
26
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EPA HEARINGS
00-017
maintain data quality. Background noise can be
of sufficient level to invalidate the
measurement.
00-017
Olpin, 0.
Utah Univ.,
Salt Lake City
On: REDUCTION OF TRANSPORTATION NOISE
Witness Statement
Public Hearings on Noise Abatement and Control
Denver, SEPT 30, 1971
of that money is allocated to the search for
cures. Concrete proposals looking toward
cures should be made by the Environmental
Protection Agency at the earliest possible
moment. It is necessary to adopt laws and
rules and regulations which will impel the
transportation industries and the consumers
of their products to shoulder their share
of this burden. Another proposal that should
be considered is to use in this effort part of
the substantial resources of the Highway Trust
Fund.
The Highway Trust Fund represents a practical
and appropriate source of support for the
solution of the problem of noise from
transportation.
Noise pollution from transportation, cars,
trucks, and airplanes is discussed. Engine
sounds from vehicles have been control led for
years by mufflers, but the market has not
provided the incentives needed to bring about
improvement in muffler technology. The aim has
been to protect the motorist from noise
pollution inside the car with windows shut;
but not those on the outside near the
highways.
A large part of the sound of the highways is
the sound of wheels rolling on the surface of
roads. This is not an unsolvable problem,
but today neither the pressure nor the market
incentive is present. The task is to create
both.
An obvious partial solution lies in measures
to assure that presently available technology
is fully utilized. In the case of mufflers
or other vehicle sound controlling equipment,
this can easily be made a part of existing
licensing and inspecting procedures. Laws
should be made firm enough to require that
licenses be denied to any vehicle not equipped
with adequate, properly functioning sound
control devices.
A special problem is posed by noise generated
by recreational vehicles. Some seem to believe
that more sound means more power, and appetites
for both sound and power seem considerable.
Motorcycles, dunebuggies, dragsters, and
snowmobiles appear to be manufactured and
operated with a purpose to maximize sound
production. There is available technology to
muffle most of the sound generated by
recreational vehicles. Up to now, however, laws
have not been passed.
Title IV of the Clean Air Act provides for a
beginning in the battle against unwanted
sound. Authorization is provided for
$30,000,000 to begin to identify causes and
sources of noise and to learn of the damage
and injury which results from noise. No part
00-018
Monaghan, J.
Colorado State Univ.
Fort Col I ins
On: RECREATIONAL NOISE
Witness Statement
Public Hearings on Noise Abatement and Control
Denver, SEPT 30, 1971
The pervasive noise created by such
recreational vehicles as snowmobiles, motor
powered boats, all terrain vehicles and the
like is discussed. The high decibel output
from some of the aforementioned recreational
sources is the antithesis of bodily and mental
refreshment. The various concepts of
recreation seem to be on a col I ision course.
Psychologists tell of the mounting need for
periodic escape from the urban environment
as a survival mechanism. Some animals and
plants are up to 30,000 times more sensitive
to noise than humans.
Noise is a national problem, and recreational
noise, produced by vehicles that are
manufactured and distributed nationally,
would be more easily regulated with uniform
requirements that manufacturers would have to
meet on a national basis. It is also felt
"that on a local level the health and individual
rights of those seeking an outdoor experience
could easily be subjugated by local interests
focused narrowly on the monetary gains of these
loud vehicles.
The Environmental Protection Agency is urged
to promulgate regulations for recreational
noise wifhin a comprehensive noise control
program and include: 1) the establishment of
uniform decibel limits on all recreational
vehicles, whether manufactured in the United
27
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00-019
EPA HEARINGS
States or imported; 2) a provision for research
of the state of the art in noise abatement
for recreational vehicles; and 3) the provision
for the periodic testing of such vehicles which
are already in use; 4) the concept of
differential use and noise zoning.
Decibel limits must be realistic within
existing technology. But the freedom of the
individual to enjoy a recreational experience,
unhampered by an obnoxious environment, is of
key importance. The concept of differential
use and noise zoning is encouraged. In This
manner, certain lakes, for example, would be
zoned for such vehicles, setting in each case
realistic decibel limits.
00-019
Lincoln, R.
Outboard Marine Corp.
Mi Iwaukee, Wl
On: MOTOR NOISE CONTROL
Witness Statement
Public Hearings on Noise Abatement and Control
Denver, OCT 1, 1971
A statement from a manufacturer of snow
vehicles, outboard motors, lawn and garden
equipment, all terrain vehicles, chain saws
and golf carts is presented. The extent to
which regulation of noise will help reduce
annoyance and contribute to the improved
quality of life is of major concern. Noise
reduction is not as simple as adding or
enlarging exhaust mufflers or building better
enclosures. Time, talent and money are
required to make a detailed technical analysis
of each product. Strict, fair and uniform
enforcement codes are a must. Without them,
manufacturers whose products do conform to
regulations will suffer severe penalties.
Noise levels of typical leisure time products
have been examined and it has been noted that
technology can probably be developed which will
reduce complaints stemming from annoyance.
These reductions will penalize the product
user in cost, weight, bulk, ease of handling
and simplicity of service. Regulations and
standards can be established which will be
realistic and feasible, but there are many
complexities to be considered if fair and
equitable enforcement is to be maintained.
Since many complaints about noise are from
members of small, special interest groups,
great care must be taken to assure that large
numbers of people are not penalized to satisfy
a few.
00-020
Yoerger, R.
I I Iinois Un iv., Urbana
On: AGRICULTURAL EQUIPMENT NOISE CONTROL
Witness Statement
Public Hearings on Noise Abatement and Control
Denver, SEPT 30, 1971
Scientific and engineering developments have
contributed to increased productivity and
reduced drugery of work on the modern farm.
However, the relative economic position of the
farmer, compared to his industrial counterpart,
has deteriorated over the last 30 years.
Before any noise regulations pertaining to
agriculture are enacted, the cost benefits
ratio must be carefully evaluated.
The farm equipment industry produces $4-
$6,000,000 worth of goods annually. The large
manufacturers have engineering and research
facilities. The small manufacturer must solve
problems on a local level and is able to
develop and modify machines quickly. Often
the small manufacturer develops new machines
and establishes the market potentials before a
major manufacturer is willing to commit the
resources necessary to add the item to his line.
In the past, equipment demanded by the consumer
each year had to be larger, operate faster and
have a greater capacity than earlier models.
Because the industry has met these demands,
productivity per worker has increased markedly.
In 1960, one farm worker produced enough food
for 26 persons; in 1970, enough for 46. The
result of building bigger machines has
generally been an increase in the sound power
level of noise associated with machine
operation. Major contributors to the overall
noise level of an operating machine are the
power source, the gear train and the various
functional components of the machine.
Industrial, professional and public service
groups have been concerned about the
identification and reduction of equipment
noise for some time. A research program at the
University of Illinois is concerned with the
noise and vibration associated with farm and
industrial machinery. The research at the
University of Illinois has been concerned with
reducing 2 of the major components of tractor
noise, that resulting from the cooling fan and
from the engine exhaust. The goal is to better
understand the mechanism of generation and
transmission of these noises and to reduce the
levels as close to the source as possible.
It is felt that the goal with agricultural
machinery should be to reduce noise level so
that there is not a serious potential hazard
to hearing loss for either the machine operator
or for associates working in close proximity to
the machine. Agricultural universities, the
28
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EPA HEARINGS
00-021
farm equipment industry, 4-H and FAA groups and
others are cooperating in an educational
program to alert the farmer and farm worker to
potential hazards and in merchandising ear
protective devices.
Each piece of new mobile equipment should carry
a nameplate certification of maximum sound
power level generated by that equipment in
operation. A consumer should be able to get
some idea of the noisiness that will result
from the operation of the equipment before he
buys it. On the national level, the goal
should be "to work toward maximum allowable
values of sound power emission for new
equipment that would not present hazards to the
operators or to the bystanders.
With this proposed procedure, the manufacturer
would be faced with a single, uniform criteria
for all equipment sold throughout the United
States, and he would be responding then to the
consumers' wishes by competing with his
associates to produce more desirable equipment.
It seems that this is the best kind of
regulation that can be developed. The state,
municipal and local bodies can then deal with
the manner in which equipment is operated, and
the resulting sound pressure levels that occur
with their operation.
00-021
Martin, T.
Boulder, CO
On: ENFORCEMENT OF NOISE CONTROL ORDINANCE —
BOULDER, CO
Witness Statement
Public Hearings on Noise Abatemerrt and Control
Denver, SEPT 30, 1971
standard. The snowmobile industry has been
notified in many ways that it has to quiet its
product. Federal pressure could eliminate
this problem.
The noise standard used in residential areas
is measured from 25 feet and has been in effect
since February, 1970, in Boulder. More than
1300 vehicles have been repaired or modified to
meet the Boulder standard. It is predicted
that unless quieter motorcycles are produced
and other methods are found to quiet the older
cycles, much of this nation will become off
limits to them. This noise level must be
brought lower than 80 dBA. Trucks are allowed
88 dBA at 25 feet and do not use residential
streets at night. Industry has been amazingly
flexible and responsible to legal requirements.
Individuals, once educated, are just as
responsive. When the Boulder program began,
eight motorcycles out of 100 were being stopped;
now, one out of 100 is the average. One
automobile out of 166 was initially in
violation; presently, it is one out of 301.
Construction noise in most cases has been
easily corrected. Most of the excessively
noisy equipment was leased, and the basic
problem was insufficient muffling. In a few
years, with proper Federal legislation, this
should cease to be
-------
00-023
EPA HEARINGS
children was probably noise induced. Sixty-
three percent of the noise induced-like loss
first appeared in the junior-senior high age
group. Of these, 8% suffered a hearing loss
progression of 10 dB. About 5 times as many
males as females suffered from this hearing
loss pattern.
The greatest percentage of children with
hearing loss came from areas where large farms
using heavy equipment were located and where
many engaged in hunting. In a less affluent
section where farms were small and not
mechanized, the children showed much less
hearing loss until fire crackers became
available on a year round basis. The
percentage of children showing noise induced-
like hearing loss rose from 22 to 37$.
The State Department of Health has tried to
make the public aware of this problem.
Warnings are circulated to hunters, and
physicians and parents of children.
Individuals manifesting hearing loss are also
warned of the dangers to hearing of shooting,
recreational and agricultural noise and
encouraged to wear earplugs or ear muffs.
00-023
Knight, K. G.
Institute for Rapid Transit
Deleuw, Gather and Company
Washington, DC
On: NOISE ABATEMENT PROGRESS IN SUBWAY
SYSTEMS
Witness Statement
Public Hearings on Noise Abatement and Control
New York, OCT 21, 1971
The two basic acoustical goals of the rapid
transit industry are: to provide system
patrons with an acoustically comfortable
environment by maintaining noise levels in
vehicles and stations within acceptable
limits, and to reduce the impact of system
construction and operation on the community
by minimizing transmission of noise and
vibrations to adjacent properties.
Notable improvements in the acoustical field
have been made since the building of early
transit systems:
1) The use of continuous welded rail has
become standard in the industry.
2) Resilient track fasteners have been
developed to reduce both noise vibrations in
direct fixation track.
3) 'Floating1 track slabs are also being
developed for use in acoustically sensitive
community areas.
4) The importance of smoofh rail and wheel
surfaces is now well recognized.
5) The transit car of today is much superior
acoustically to its predecessors.
6) In underground stations particularly, noise
levels are being reduced and reverberation
times shortened by the use of acoustical
ceilings and under-train-platform absorption
systems.
7) Modern and attractive aerial structures which
are replacing transit's old "els" are combined
with acoustically designed track fasteners and
will be as quiet as they are attractive.
8) Sound barrier walls have been developed for
use on surface and aerial lines where
additional acoustical privacy is required.
9) Acoustical design criteria for ventilating
fan selection and fan and vent shaft design
are in general use.
10) Ancillary mechanical and electrical
equipment and facilities have been improved
with more attention being given to reducing
noise from this equipment.
Funds to make capital improvements in
existing systems are frequently lacking.
Basic research is required to establish more
clearly the effects of noise upon people and
to establish appropriate criteria for the
noises of the types generated by transit
system operations. Equal effort should be
extended in educating the public and providing
them with information. With an educated public
as our goal, criteria scales should be
standardized throughout the industry. The
trend in criteria establishment seems to be
towards the use of simple, easy-to-measure,
A-weighted sound levels, and this type of
standardization is desirable.
The transit industry concurs with EPA's
ultimate goal 'to achieve a desirable
environment in which noise levels do not
interfere with man's health and well-being or
adversely affect other values which he regards
highly.'1 However, the industry needs
assistance in basic acoustical research, in
the development of new and improved control
techniques and in the establishment of
economically attainable noise criteria which
may be easily comprehended by the public.
Additional financial assistance is required
in order to modernize existing systems and
provide the basic noise and vibration controls
which are now attainable through technology.
Because of the wide divergence in age and
character of existing rapid transit systems,
it is obviously impossible to set a standard
that alI may follow. There must be deviations
30
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00-024
EPA HEARINGS
from the guidelines established in order to
achieve compatibility. It is believed that
transit officials recognize their obligations
to the community and that a system of self-
imposed discipline in noise control, supported
by the technical and financial assistance of
government, will prove superior in the long
run to enforced legislation relative to noise
vi brat ion.
00-025
McCollorn, H.
Hearing Conservation Center,
Lancaster, PA
On: SOME UNRECOGNIZED NOISE PROBLEMS
Witness Statement
Public Hearings on Noise Abatement and Control
New York, OCT 22, 1971
00-024
DriscolI , J.
Hempstead County Government,
Hempstead, NY
On: AIRCRAFT NOISE ABATEMENT
Witness Statement
Public Hearings on Noise Abatement and Control
New York, OCT 22, 1971
Suggestions on regulatory agencies and
procedures for control of aircraft noise are
presented. It is felt that noise is not only
a product, but a I so a problem of the
environment, and its control should be in the
hands of the Environmental Protection Agency
rather than in the hands of the Federal
Aviation Agency.
A demonstration at Minneapolis-St. Paul airport
is reported of aircraft operating procedures
which did achieve very noticeable lowering of
the noise levels of existing aircraft in the
present jet fleet. Purely by changing the mode
of operation and pilot technique the planes
were quieter.
EPA is asked to provide the impetus behind a
program which will in effect regulate the air
carriers and make them operate the present
aircraft in a less noisy fashion. This can be
done without any expenditures of vast sums of
money.
A discussion of 3 examples of noise problems is
presented. The first is the ultrasonic
vehicle motion detector used with traffic
lights to control flow of traffic. Its 18,000
Hz signal is in the upper level of human
hearing found in nearly all children and many
young women. At the lens opening a 120 dB
signal is produced. Many parents are concerned
when their children scream and hold their ears
at certain highway intersections.
The second example is a hazard of the future.
The air bags being considred for automotive
safety will inflate with a literally deafening
170 dB. The presently available facts and
technology should be used to pre-plan against
noi se.
Thirdly, the population of Lancaster, PA, has
not changed appreciably in 10 years. However,
calls to the police concerning noise in the
month of August 1969 were 105, while in August,
1971 there were 189. On a very conservative
scale this extrapolates into a national figure
of $52,000,000 per year just answering noise
complaints. These figures suggest that noise
is increasing without respect to population
growth or people are changing their attitudes
and complaining more or both.
00-026
Dougherty, J.
Harvard University,
Cambridge, MA
School of Pub!ic Health
On: EXTRA-AUDITORY EFFECTS OF NOISE
Witness Statement
Public Hearings on Noise Abatement and Control
Boston, OCT 28, 1971
A discussion of the short-term physiologic,
apparently reversible, effects of noise and
the longer term, usually irreversible effects
31
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00-026 (CONT.
EPA HEARINGS
of noise, and the common
is presented.
,'inks between the two
The short-term physiologic responses to noise
are quite similar to those found with
emotional stress in animals and man. The
similarities have been documented by recording
change in blood pressure, pulse pressure,
heart rate, perspiration, widening of the
pupil, or change in fetal blood flow. When
blood or urinary hormone levels are assayed,
noise again causes changes similar to those of
emotional stress. Blood levels of long-acting
hormones such as adrenocortiocoids (from the
cortex of the adrenal gland) are increased by
noise. Levels of shorter-acting (adrenalin-
like) hormones from the center of the adrenal
and from nerve endings are also increased.
The strength of the response is primarily
related to either the dB level or the
emotional content of the noise.
Emotional content of noise is a function of
several variables. Among them are the
individual's previous experience with or
prejudice toward a noise, the frequency, band
width and rate of change of this change, the
amount of startle associated with the noise,
the degree of interference with activity, the
amount of background stress already
experienced by the listener, and the
emotional health of the listener. However,
even without any awareness of an emotional or
physiologic response (in some cases when
anesthetized), the listener will manifest most
of the physiologic responses noted above.
Clearly the willingness of an individual to
cheerfully accept noise stresses is no
guarantee of his immunity to extra-auditory
effects.
Animals which are exposed to chronic noise
stress develop much the same disorders as are
associated with emotional stress in humans.
Diseases such as arterial hypertension,
arteriosclerotic vascular disease, myocardial
infarction, emotional instability and birth
defects have been caused by experimental noise
exposures in animals.
Several experiments have been performed which
show the similarity between noise and other
forms of stress in the genesis of stress-
related disease. In general, the same
hormonal and central nervous system pathways
are involved. No experiment is known which
has described a dose-relationship between
noise and pathologic effects. However, when
stimulation of central nervous system pathways
of animals was held to the same level of
physiologic response as seen in humans with
70-80 dB white noise, marked arteriosclerotic
change occurred in animals fed atherogenic
diets. These changes were not seen with the
diet alone.
Increased rates of a number of disease
processes in workers subjected to industrial
noise have been described in the Russian
literature. In general these studies have not
been well controlled.
The need for well-controlled human studies is
further supported by the lack of experiments
performed with animals which — like humans —
have phlegmatic response to noise. Studies of
the effects of noise stress on animals such as
dogs or primates would provide valuable
evidence for or against the role of noise in
stress-related human disorders. The absence
of a causal link between noise and stress-
related disease in noise tolerant animals
and the paucity of well-controlled studies of
human exposure constitute the greatest
weaknesses in any attempt to indict noise as
the cause stress-related disease in humans.
Only two studies have clearly linked noise
stress to human extra-auditory disorders. In
one, performed on hospital patients, those
recovering from myocardial infarction
experienced 3 to 4 times larger adrenergic
hormone outputs following a standard noise
stress than other hospital patients. The
second paper dealt with admission rates to
mental hospitals from equivalent socio-economic
groups with the only known difference being the
flight paths to and from Heathrow Airport.
This airport is near London, England. No
significant differences between noisy and quiet
areas were found in various subgroups of the
population except in older single women who
had the highest rate of admission in the quiet
areas. Admission rates for this group were
significantly elevated (still higher) in the
noisy areas. These studies are interesting
because they both demonstrate a heightened
susceptibility to noise in groups of people
who have demonstrated an increased
susceptibility to stress-related disease.
A number of areas for future research are
I isted.
1) Do noise-tolerant animals such as dogs or
monkeys develop stress-related disease or
birth defects after exposure?
2) What role does the aging process play in
effects of noise on animals or human stress-
related disease?
3) What are the effects of noise upon
individuals with pre-existing disorders such
as arteriosclerotic vascular disease, diabetes
or emotional illness?
4) What is the relative importance of noise
stress among other environmental stresses such
as automobile driving, excitement or anger,
diet or biochemical stresses such as
atmospheric lead or cadmium?
Clearly such research would be multivariant,
would require a number of years to perform and
would be costly. However, control of
environmental pollutants is costly and should
be based upon a priority ranking derived from
an estimate of the relative costs or benefits
of each dollar spent for control.
32
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EPA HEARINGS
00-027
00-027
Standley, D.
Boston Air Pollution Control Commission,
MA
On: PROPOSALS FOR A NOISE ORDINANCE IN BOSTON
Witness Stafemenf
Public Hearings on Noise Abatement and Control
Boston, OCT 27, 1971
00-028
Sutton, A.
Burgundy Farm Country Day School,
Alexandria, VA
On: STUDENT RECOMMENDATIONS FOR NOISE CONTROL
Witness Statement
Public Hearing Noise Abatement and Control
Washington, NOV 12, 1971
The Boston Air Pollution Control Commission was
charged in APR, 1971 with jurisdiction to
investigate, control and abate noise in
Boston. A report on noise was prepared by Bolt,
Beranek, and Newman, Inc. (BBN) under a
commission contract, in the light of which the
Commission has drafted proposed interim
standards for community noise, and initial
noise abatement regulations, patterned closely
after "the Chicago ordinance. A public
hearing has been held, comments reviewed, and
the regulations drafted. The redraft is now
in review, and the sfandards and some
regulations will be adopted in the very near
future.
The Commission proposes that noise in
residential areas attributable to land uses in
or abutting those areas be limited to
approximately 60 dBA in the daytime, 50 dBA at
night and on Sundays. Limits on "the noisiness
of new motor vehicles, construction equipment,
recreational vehicles, and other powered
equipment for outdoor use are proposed. These
take the form of certification requirements
imposed at the point of sale or lease. Still
being reconsidered is a restriction of the
noisiness of construction activities. It is
felt that noise from this source should not
exceed by more than 10-15 dBA the noise
standard for the area in which the construction
occurs. The framework for a system of
registration of certain noise sources and
rennits for others is being developed. It has
been possible, to date, to a! locate not more
than $25,000 per year to this noise abatement
act; vi ty .
A certification requirement for motor vehicles
of 7'3 'fiA, at rifi foot, :o be mot by 1980 is
EPA is urged to take the lead in standardizing
measurement , test, and certification
procedures, and methods for expressing the
impact of noise. Complete Federal preemption
of the sf andard-setti ng process is, however,
unnecessari ly restrictive of the right and
opportunity for communities to achieve the
environmental quality they wish.
Suggestions for noise control from a group of
sixth, seventh and eighth grade students are
presented. These students were completing a
science study unit on noise. Some of the
suggestions were: the passage of anti-noise
codes throughout the country, semi-annual
noise inspections for all vehicles, and strict
enforcement of a night curfew at Washington
National Airport; passage of laws aimed at
stopping noise at its source; retrofitting jet
airplanes, quieter horns on motor vehicles;
production of quieter home appliances. The
Washington Subway System should be made as
acoustically quiet as possible. The
development of quieter drills and jackhammers
is needed. Workmen around loud noises should
be required to wear ear plugs, until the
noise level around them can be reduced. EPA
should sponsor a yearly national anti-noise
week or day and is urged to develop a vigorous
campaign to educate the public.
A discussion of the course content followed and
it was suggested that EPA would be interested
in fostering further work about environmental
ecology at the secondary and primary school
level.
00-029
Goldshore, L.
New Jersey State Department of Environmental
Protection
On: FEDERAL VS. STATE STANDARDS-PREEMPTION
Witness Statement
Public Hearings on Noise Abatement and Control
Washington, NOV 11, 1971
Testimony generally in favor of the bill,
S.1016, is presented. Exception is taken to
Section 6(d), which appears to preempt the
adoption of state regulation of certain noise
sources. This section raises some
questions regarding the relationship of Federal
33
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00-030
EPA HEARINGS
regulation and enforcement to State activities
in the field of environmental protection. It
does not appear to be in the public interest
to preempt a state from jurisdiction to protect
its citizens from environmental insults. The
Federal Government does not have the manpower,
or data base, or the ability to take over
environmental control. It is suggested that
S.1016 should be amended to allow for stricter
state regulation if the state desires it.
The following relationship between the States
and the Federal government is suggested:
The Federal government may adopt legislation
which enables a national regulation of
activities which can have a harmful impact on
the environment. The severity of these
regulations should, however, serve as
nationwide minimum, not as limitations. Thus
those states that wished, could adopt more
stringent regulations, and enforce them. This
pattern is important if New Jersey is to clean
up its severe environmental problems. New
Jersey population density is the highest in the
nation. The state has more vehicles per square
mile than any other state in the union. If the
Federal government were The sole regulatory
body, New Jersey would be governed by the same
regulations as Wyoming and Colorado, where the
environmental problems are not so severe.
It is important for the regulations established
by the Federal government to be applicable
nationwide so that pirating industry from more
protective states could be avoided. It is also
important for the Federal government to have
its own set of nationally applicable
regulations so that it can step into the
enforcement area if the State falls down on the
job.
Other sections of the biI I
briefly.
were discussed
The CounciI of Governments proposed a program
to assess the nature and extent of the noise
problem, examine successful existing and new
control techniques, and develop a noise control
ordinance, a noise control section of a land
use planning policy, and other programs. This
was to take 3 years under an inter-disciplinary
Noise Control Advisory Committee and a noise
control engineer. The total cost was to be
$130,810 of which 25% would come from the local
jurisdictions. This was refused, but
suggestions were made for modification and
resubmi ssion.
Modifications included the identification of
and reduction of hazardous and stress producing
noise in the environment. This program also
was to take 3 years and was subdivided into the
following tasks: I) review literature, 2)
inventory current noise control activities,
3) inventory and rank major noise problems,
4) design noise level and opinion surveys,
5) assist local jurisdictions in establishing
noise monitoring plans, 6) carry out public
education and information activities, 7)
conduct and analyze noise level and attitude
surveys, 8) rank-order noise problems, 9)
demonstrate specific control measures, 10)
develop noise control goals and objectives,
11) develop a set of noise control standards,
12) develop a model noise control ordinance,
13) develop a set of local noise control
policies, and 14) develop a set of action
programs and policies which can be undertaken
by non-local governmental agencies, by private
industry and organizations and by individual
citizens. The total budget for this project
was $312,130. This was rejected because
existing priorities allowed only new family
health care projects to be funded.
In the discussion which followed, it was
suggested that projects of this type would be
valuable and hopefully funding could eventually
be obtained.
00-030
Lentz, J. L.
Metropolitan Washington Council of
Governments, DC
On: REGIONAL PLANNING
Witness Statement
Public Hearings on Noise Abatement and Control
Washington, NOV 11, 1971
00-031
Kreml, F. M.
Automobile Manufacturers Association,
Washi ngton
On: MOTOR VEHICLE NOISE ABATEMENT
Witness Statement
Public Hearings on Noise Abatement and Control
Washington, NOV 12, 1971
A discussion of the problems encountered by a
regional association of local governments
when it tried to obtain funding for a noise
pollution study is presented.
Since the object of motor vehicle noise control
is to minimize annoyance to the public, the
Automobi le Manufacturers Association
commissioned a study to define what aspects of
motor vehicle are most annoying to people. The
34
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00-032
EPA HEARINGS
study was intended to establish guidelines to
needed areas of acoustical improvement of
vehicles by manufacturers.
Some of the findings of the study are:
A. To reduce annoyance from motor vehicles most
rapidly, the noise from vehicles that cause
peaks above background levels should be
reduced, because it is the occasional noise
excursion that produces most complaints.
B. In the majority of cases where people
expressed annoyance at a specific vehicle noise
event, they felt that it was a situation the
driver could control, such as tire squal, hot
rodding, and similar operations.
C. Annoying noise sources are relatively close
to the auditor, e.g., 70? of the exposures
described as annoying within 100 feet of the
noise source.
D. Most people who express annoyance indicate
that they are at home when the annoyance occurs
and it is generally in the evening.
As regards trucks, reduction of truck noise is
difficult because of the varied cnaracteristies
of the many sources on each vehicle. Included
are exhaust, engine mechanical noise, air
intake, fan, transmission gears, tires and
other miscellaneous mechanical appurtenances.
Truck noise reduction is not a question of
putting on an improved muffler. Muffling is
available for most trucks that effectively
eliminates exhaust noise as a consideration.
Tire noise is one of the most serious obstacles
to noise reduction at high speeds. The impact
on the cost of transporting goods due to
vehicle modification to achieve stringent noise
levels must be considered. There may be an
increase in initial equipment cost. Sales of
trucks and buses in the U. S. in 1970 amounted
to $4.8 billion; therefore, a }% increase in
cost wculd be $48 million that must be borne
by the general public. Since there are overall
weight and length restrictions, vehicle
redesign which involves more space or increased
weight must do so at the cost of reduced cargo
capacity.
There would also be increased maintenance costs
because of more complex construction and
possible higher engine temperatures.
A strategy for reduction of noise annoyance is
presented in the following recommendations:
A. That, after thorough study of need, uniform
national standards be issued, with Federal
preemption and consideration of possible
conflict or trade-offs involving safety and
emissions standards.
B. That model legislation be developed for the
guidance of states and local communities.
C. That effective enforcement procedures be
developed for state and local use.
D. That a long-range policy of motor vehicle
noise reduction be undertaken, taking
technological and economic feasibility into
account.
E. That substantial research efforts be
undertaken addressing the problems of: tire
noise, technology of noise reduction, and
comparative economic impact of noise regulations
at various levels.
00-032
Larimore, H. T.
Construction Industry Manufacturers
Association, Chicago
On: ECONOMIC FACTORS IN NOISE REDUCTION OF
CONSTRUCTION EQUIPMENT
Witness Statement
Public Hearings on Noise Abatement and Control
Washington, NOV 12, 1971
Economic considerations of noise control in
construction machinery and industry
recommendations are presented.
Manufacturers of construction equipment admit
that many of their products are noisy.
Construction contractors have not been
motivated to engage in research for methods
to reduce noise and have not asked
manufacturers for quieter machines. Thus, the
machinery manufacturers have developed
machines with increased productivity and lower
costs per unit of work output but not quieter.
There does not seem to be any imminent
technical breakthrough which can overcome the
problem of noise reduction. Noise reduction
is a step-by-step process of analyzing each
noise producing element of a machine and
reducing it to a level which is below the dBA
level of other sound-producing components.
A 3 to 8 dBA reduction could be achieved at o
cost penalty of 10 to 24 percent over • rei~iuc
of 5 years.
In various studies of environmental noise,
emphasis is primarily given to urban areas of
hign population density. Demolition and
construction have in many of these locations
become almost a continuous process. This is in
contrast to highway and civil works
construction projects which, when completed,
are utilized for many years without new
projects being undertaken nearby.
A review of Bureau of Labor sta+isties
information reveals that there- is a substantial
difference in the expenditures for machinery
35
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00-033
EPA HEARINGS
used for buildings (1 to 2% of project
cost) compared to tne machinery used on
highways (12?) and civil works — land
(20?). It can easily be seen that
increases in machinery cost will be reflected
to a much greater extent in project costs on
large rural e^rthmoving jobs rather than on
building projects. In other words, the cost/
effectiveness ratio of noise reduction is far
better in urban areas. It would therefore seem
appropriate itvut current efforts of n>i~<>
reduction on construction equipment be
initially limited to urban site construction.
Government, .o., Federal, State and Local, is
the largest , tistomer of the construction
industry. In a Conference Board article
entitled, "Economics of the Construction
Industry," the author states, "the share of
public construction in total construction has
increased from 22 percent in 1945 to 34 percent
in 1967. it is generally believed that this
trend will con} i nue",
On a trial basis, it would appear that tie
Federal Government, through EPA, is in the best
position to initiate pilot cost studies. On
certain selected contracts, the Government
could specify maximum noise levels f-'r the
construction site. Separate accounting could
be established to determine the costs, record
the techniques used to limit noise radiation
and nore compliance jitticuIties.
The Construction Industry Manufacturers
Association (CIMA) points out the following:
1) Member companies are working on machine
noise redi.'-t ion r ^w and are faced with the
necessi ly if pushing the threshold of The art
onto ne^ technological ground.
2) In response 1o CIMA f'e- forman.-o Standards
action, vai ious standards writirg bodies,
including SAE, are establishing uniform,
definitive and repeatdble noise measurement
standards using dBA. CIMA strongly opposes
reported current efforts by some noise
fechrr |->us ro develop a different ^a'e,
which rould seriously delay the noise abatement
effort" by causing several years or noise
meacur foment to be re-studied.
3) Member companies generally do not oppose
r^: ilstic individual noise lirpits for selected
!!,;< ii • • _* , ' «n under standardized conditions
and test .m , "..•>•. to give the repeatable results
necessary ~or any c-:-r + i f ', jti on or labeling
requ iiemen t.
4) Member companies do not oppose individual
macn'ne n^iss- output labeling, but do not think
'"tat labeling requirements should be applicable
to export snipments until such time as this may
become a requirement for a I I manufacturers on
ar in-e. :ational basis.
6) Members generally believe that national
noise limit Standards could apply to selected
individual machines, but control of the total
job site noise impact on the adjacent community
should be a State and/or Local Government
perogati ve.
00-033
Singer, A. A.
National Association of Home Builders,
Philadelphia
On: QUIET HOUSE PROGRAMS
Washington, NOV 9, 197!
The National Association of Home Builders
(NAHB) initiated efforts relating to noise and
sound conditioning over 10 years ago. "Quiet
House" programs were undertaken to familiarize
the consumer with welI-designed housing and to
determine the consumer's interest in such
features. A Residential Sound Conditioning
Manual was developed to aid builders in
providing cost-effective acoustical housing
env i ronments,
The NAH6 Research Foundation, Inc. has
continued research to measure in-place
acoustical performance in relation to
construction, fne Dackground noise levels, and
the subjective response of the occupants.
Three studies have been made, involving
measurements of airborne noise reduction,
impact sound transmission with various impact
sources, and the interior 'ivJ exterior
ambient noi-e levels.
Each improvement to performance level increases
the cost of housing, and it is essential that
a balance between cost and performance be
struck so that j reasonable degree of quiet
is provided wi khout ad'*e; -:c I y o^fectinq the
ability of all to live in decent housing.
Several years nyo, an attempt wa: made to
develop special construction techniques within
the house and special appliances and equipment
t"'"" Deduce the noise level in the house. This
was offered as an optional extra at a cost of
about $1000. Many were interested, but few
w i I Iing to pay. The buiIder then sea Ied the
package down to $100, dealing only with 1 he
areas of high noise level and found many who
would invest at this level. It was suggested
by the pan-°l that perhapr- with publicity or!
noise abatement1 more customers would now be
willing to pay the $1000. These houses
rangecTin price from $20,000 to $40,000.
36
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00-034
EPA HEARINGS
The most significant acoustical problems are
those between apartments, while noise sources
within the home or apartment are of less
concern and exterior noises are least
disturbing. In apartment buildings, structure
borne noise transmission is the cause of most
disturbance, particularly impact noises are
bothersome since they are developed within
units and transmitted between units. Airborne
noise is not as significant a problem as it was
10 to 20 years ago. Electrical outlets in
party walls reduce the effectiveness of
otherwise satisfactory construction. Revision
of the National Electrical Code, and changes in
local enforcement practices are needed so that
electrical outlets are not required in party
walls. The problems of economically isolating
sources of vibration from the building
structure need more attention. Basic to
solution is the need for development and
acceptance of measurement techniques and rating
methods. The generally used ISO method of test
for impact sound transmission and the Impact
Insulation Class rating system have given equal
ratings to floor construction which may vary
400? in loudness of transmitted footfall noise.
Only when improved methods of evaluation are
developed, can the development of practical
construction and installation techniques be
utilized to reduce the problem. Similar
comments are applicable to problems of
transmitted plumbing and appliance noise.
In various studies, it was found that some
occupants are bothered by noise of kitchen and
other appliances when they are in another room.
Each of these noise sources is amenable to some
control, but most people are unwilling to pay
the initial cost of "quieter" appliances or
modified installation techniques.
Manufacturers should be encouraged to find more
cost-effective noise control techniques.
EPA and other governmental agencies should
continue to encourage and support continuing
and coordinated research into the effects on
people, the development of techniques of
measurement and evaluation of noise, and the
development of practical and cost-effective
noise-control techniques.
Specifically, it is suggested that further
research is needed on the following subjects:
(1) Automobile and truck noise, including the
design of efficient yet quiet engines and
exhaust systems, truck and autombile tires, and
techniques of highway design to minimize its
effects upon the surrounding land use.
(2) Aircraft noise control, including the
development of quieter engines and aircraft use
patterns that minimize intrusive noise.
(3) Structure-borne noise transmission,
including development of physical evaluation
techniques that permit rating products and
elements of dwellings and buildings in the
manner that people respond to them in use.
(4) More cost effective methods of reducing
appliance and fixture noise.
(5) Development of economical, practical, and
market acceptable window and door systems
specifically designed to minimize excessive
exterior noise intrusion.
Additionally, EPA might consider study of
enforceable legislation and regulations which
local and state governmental bodies could use
to keep exterior noise and disturbance at
reasonable levels.
Finally, EPA should encourage manufacturers
to label noise levels of appliances, equipment,
and related items under a rational and
consistent rating system to inform consumers
so they may evaluate the equipment in relation
to noise.
Transportation noises such as those produced by
airplanes, trucks, automobiles and trains are
the primary source of exterior ambient noise.
Other noise sources include building
mechanical equipment, powered lawn and garden
equipment, power tools, snowmobiles and other
off-the-road vehicles. Primary emphasis at
this time should be on further research and
development and voluntary efforts by producers
to reduce excessive noise levels. However,
some legislative or regulatory measures might
be considered for this equipment provided
practically attainable performance levels are
estabIi shed.
One of the recent attempts to provide good
acoustical environment is HUD's establishment
of interim standards for evaluation of
community noise. Because this is only a first
step and its effects have not been tested,
judgment must be reserved on its practicality
and on the criteria themselves. Government
planners at all levels might be required to
consider the effect of new highways and
airports on the noise levels of existing or
planned land uses prior to the decision to
impose such facilities on the local
community.
00-034
Orski, C. K.
Organization for Economic Cooperation and
Development, Paris /France/
On: TRAFFIC NOISE REDUCTION
EUROPE
Witness Statement
Public Hearings on Noise Abatement and Control
Washington, NOV 9, 1971
The Organization for Economic Cooperation and
Development (OECD) has been conducting
investigations in the field of noise
abatement for a number of years as part of its
program of international cooperation in the
field of environment. The inclusion of noise
within the program has been a reflection of the
37
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00-035
EPA HEARINGS
growing bel ief on the part of OECD member
governments that noise, no less than some of
the more visible forms of pollution, represents
a real threat to the quality of the environment
and to the well-being of people. Activities
have ranged over such subjects as airport
noise, sonic boom, and most recently, motor
vehicles. The reduction of noise levels in
urban areas ranks high on the agenda of almost
every OECD government.
Within OECD, the concern about traffic noise
has led to the creation of a special task
force to develop guidelines for a model
national traffic noise abatement strategy. The
recommendations of the task force stress the
necessity of vehicle noise emission standards
and effective enforcement machinery as a
prerequisite to any substantial reductions in
urban noise levels. Such standards should be
made progressively more stringent.
Studies within OECD concerning vehicle noise
abatement are continuing in the context of a
major inquiry, "The Impact of the Motor Vehicle
on the Environment." The aim of this project
is to carry out a broad technology assessment
of the motor vehicle in order to aid member
governments in the formulation of comprehensive
strategies toward the automobi le.
The United Kingdom's proposed 1973 noise
emission limits for new vehicles are:
passenger cars, 80 dBA; trucks (less than 200
hp), 86 dBA; heavy trucks (more than 200 hp),
89 dBA. The limits recently agreed to by the
Common Market countries are: passenger cars,
82 dBA; trucks (over 3.5 tons), 89 dBA; heavy
trucks (more than 200 hp), 91 dBA.
economic analysis of alternative vehicle
designs with reduced noise emission
characteristi cs.
In Sweden, Volvo has recently announced the
design of a new 320 hp diesel engine which is
6 dBA quieter that current engines of equal
horsepower. The cost of the new engine is
estimated to be 5% higher than the cost of the
current engine.
Attention in Europe is principally focused on
reducing the noise output of the vehicle system
itself, while comparatively little attention is
devoted to the problem of tire noise or
aerodynamic noise. This is because in the
typical European driving conditions the engine
exhause noise clearly predominates over the
latter.
00-035
Bricken, G.
Northrup Aircraft Company,
Los Angeles
On: A COMPUTER BASED NOISE MONITORING SYSTEM
Witness Statement
Public Hearings on Noise Abatement and Control
Washington, NOV 10, 1971
It is a preliminary conclusion that reductions
of 4 decibels or higher are envisageable, but
probably only over the longer run since they
would seem to require more fundamental changes
in the vehicle system. Nevertheless, a British
working group has recommended a reduction in
noise limits down to 75 dBA for passenger cars
and 80 dBA for trucks, these proposed standards
to take effect in I960.
Following is a compendium of proposed European
legislation concerning vehicle noise emission
standards:
There is a research program in the United
Kingdom with the objective of developing a
"quiet'' 80 dBA diesel truck. The project is
looking at ways of minimizing both body and
tire noise as well as engine exhause system
noi se.
A private company in the U. K. has announced
the design of a diesel engine with noise
emission characteristics 4-9 dBA lower than
those of a conventional diesel of the same
horsepower. In Germany, the firm of Heinrich
Gil let, in cooperation with the Universities of
Cologne and Essen, is carrying out, under the
auspices of the German Engineering Society and
the Ministry of Transport, a technical and
Systems, services and products designed to
bring about constructive solutions to
environmental noise problems are discussed.
Little has been done in the past 10 years to
systimaticaIly apply known technology to
control the presently controllable aspects of
jet aircraft, namely, operations. Control of
flight paths, flight schedules, and persistent
noisy aircraft can bring about a decrease in
airport community noise exposure. Such
management of noise is possible through the
use of modern data acquisition and data
processing techniques. At the Orange County,
California, Airport an area-wide noise
monitoring system operates 24 hours a day.
The system, Ecolog I, serves as a tool for the
airport to administer its program of managing
aircraft noise. The system consists of 5
sensors, 3 located in the normal departure
zone of the airport in triangular array, and 2
located on the normal approach zone. This
layout is used for evaluation of conformance to
noise abatement procedures, determination of
violation levels, and assessment of community
noise exposures as prescribed in the new Noise
Regulation for California Airports. The system
consists of field stations with microphones
and electronics to convert sound levels for
transmission to a central location. At this
38
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00-036
EPA HEARINGS
location is a processor consisting of an input-
output buffer and computer for arranging and
manipulating the data for output to 2 display
devices. The computer program provides a
multiplicity of easily adjusted variables to
assist the user in interpreting and extracting
needed information. The airport obtains
single event readings for every aircraft
departing and arriving, single event
violations, automatic hourly energy averages,
and daily energy averages. Continual
surveillance and analysis of computer produced
records allow the airport to obtain accurate
statistical records of noise levels and changes
in those levels. Real time operation allows
the airport to respond immediately to community
complaints and to immediately signal offending
aircraft of their violation condition.
Small systems can be acquired for $30,000 to
$50,000. Larger systems can run as high as
$200,000. Operating costs will run several
hundred dollars a month.
Only 3 such systems are in operation in the
United States. Three problems stand in the
way of wi der use.
First, the lack of simple and convenient
standards for measurement make it difficult to
develop equipment for wide-scale application.
Secondly, there is no clear-cut jurisdictional
authority for noise control at airports.
Finally, there is no real mechanism for
bringing citations against violators of local
noise ordinances drawn in spite of the specter
of federal preemption. Although the technology
for such noise abatement is available today and
can be applied in some cases at reasonable
cost, wider benefit will only come about when
there are more definitive assignments of
responsibility, standardization of measurement
indexes and constructive regulatory criteria.
be allocated until the last dollar spent on any
one commodity yields the same satisfaction to
society as the last dollai spent on any other
commodity. Given the fundamental fact of
scarcity of resources, less pollution must
mean fewer other goods and services. Thus if
society wants less noire, clsaner air and less
polluted rivers and seas, it must realize that
the cost of less pollution is other goods am!
services foregone. Society must order its
priorities. What costs are we o^epared tr> pay
to enjoy less pollution? For almost all types
of pollution, costs rise disproportionately in
relation to the degree of non-pollution. To
reduce the noise level from the local freeway,
the local community must decide if the real
costs, that is, other goods and services
foregone, are worth the reduction in noise.
The reduction in noise will be the marginal
benefit; the alternatives forego the marginal
cost. If the former exceeds the latter, the
project is worthwhile. Unfortunately, with
many projects, the benefits are difficult to
measure.
The policy implications can be stated as
follows: 1) educate the public to understand
how pollution arises, the costs of pollution,
and fhe benefits of pollution; 2) establish
criteria for solving the pollution problem;
3) devote resources to the development of
measuring tools of pollution since successful
legislation will require an ability to identify
pollution and degree of pollution; 4)
implementation of criteria to establish who
should pay to decrease pollution levels. In
some cases, value judgments can be made
satisfactorily by designated officials who will
act in compliance with established criteria.
In other situations, however, a vore of the
people concerned is the most satisfactory method
to determine whether a noise polluted community
is in economic equilibrium with other
conflicting demands of the populus.
00-036
Lumsden, K. G.
California Society of Professional
Eng i neers
On: THE ECONOMICS OF NOISE POLLUTION
Witness Statement
Public Hearings on Noise Abatement and Control
Washington, NOV 9, 1971
00-037
Howe, J. T.
Engine Manufacturers Association,
Chicago
On: LEGAL ASPECTS OF NOISE CONTROL
Witness Statement
Public Hearings on Noise Abatement and Control
Washington, NOV 11, 1971
A discussion of the factors involved in the
economics of pollution with emphasis on noise
pollution is presented. The general rule for
economic efficiency is that resources should
Three areas which provide the foundation for
any effective program to legally control noise
emissions are discussed.
39
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00-038
EPA HEARINGS
First, the need for objective standards which
are achieved by a balancing process which takes
into account the relative position of ah
parties is an approach which has the capability
of protecting the interests of a I I. A review
of arguments for and against uniform standards,
and the test procedures and enforcement methods
used +o enforce them is mandatory.
Representative cases show that common law
remedies '~a~ed upon subjective standards are
not the ans'.v'?r. In each situation, the case
must be dec iced on its own merits through a
lengthy trial.
Considering statuatory and regulatory
approaches to the problem, it is noted that
each s+ate, with the exception of Alaska, has
adopted some legislative or regulatory scheme
for the legal control of noise emissions from
motor vehicles. In 1969, the Department of
Commerce's panel on noise abatement examined
stare and local ordinances concerned with
noise control. This study noted that
vehicular noise control in 32 states was
limited to muffler requirements. In
seventeen states and the District of Columbia,
the basis of noise control was a subjective
"disturbing the peace" appraoch with some
objectivity occasionally interspersed by The
regulation or statute setting specific no.se
standards. Other methods limiting or
prohibiting noise sources have been adopted in
several states.
In 1969, only 3 states had specific noise
standards, with regulations, imposing criminal
penalties for noise measured at prescribed
distances from noise sources. Since 1969,
however, many states, in response to the need
for some legislation, have been enacting laws
and regulations. Standards applicable to
engines should be balanced between the concerns
for the environment with the benefits of
technology. The establishment of fair and
equitable standards, with technological and
economic feasibility being a major factor to be
considered on an increasing basis as heaifh or
medical considerations decrease will be to the
benefit of all. Such standards should tahe
into consideration their effect on other
environmental areas.
The question of preemption was dominant in
these hearings. Noise standards range in some
states from a low of 74 to a high of 90 dBA.
There is a lack of consistency in enforcement
methods. Some local governments have passed
standards but failed to adopt any enforcement
procedure. The Engine Manufacturers
Association (EMA) recognizes the need for
effective legal control of noise emissions and
supports uniform federal standards and
enforcement procedures with federal preemption.
Also, because of the variances in test methods,
a uniform procedure should be established under
the aegis of one Federal government agency,
preferably The Environmental Protection Agency.
This agency, in turn, should be given the
authority to delegate responsibility for
enforcement of noise standards applicable to
engines to state and local governments which
adopt identical plans in accordance with the
uniform procedures established by the Federal
government.
Opponents to uniform standards, or preemption,
have expressed the concept that only the state
or local government can do the job effectively.
A thorough understanding of any law is always
essential for its effective enforcement. By
permitting confusing and conflicting noise
standards, it would be impossible for the
public to understand and difficult for the
industry to respond and comply with such
standards. It is also important that only one
agency within the Federal government itself be
charged with the responsibility for the
promulgation of standards.
00-038
Bennin, R.
Bureau of Noise Abatement,
New York
On: MUNICIPAL NOISE CONTROL
Witness Statement
Public Hearings on Noise Abatement and Control
Washington, NOV 11, 1971
The groundwork for a comprehensive urban noise
abatement program for New York City is
discussed.
With the help of HUD the first leg of a pilot
study has been completed. When the study is
completed, a methodology for accurate and
comprehensive measurement of urban noise will
have been developed.
A Noise Control Code has been developed which
may become a model for the nation. It is
stronger and more comprehensive than any other
code in the country. The Code attempts to deal
with urban noise pollution in 4 ways: through
1) statutes on unnecessary noise modeled after
those already on the books; 2) specific decibel
limits on a number of noise sources, such as
air compressors, paving breakers, etc.; 3)
ambient noise quality zones for the different
communities of the city; and 4) and enforcement
section patterned after the recently passed Air
Code which will bring noise violations before
our Environmental Control Board instead of
criminal courts.
The Bureau of Noise Abatement currently handles
more than 400 complaints a month using moral
persuasion and community pressure since its
legal power is limited.
40
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00-038 (CONT.
EPA HEARINGS
Currently the Bureau has a staff of seven and
an operating budget of $100,000. When the code
is passed, the need for a force of 15
inspectors, plus 3 equipment certification
officers, an acoustical engineer and 2
electronic technicians is predicted at a cost
of $250,000 and $500,000 for the study and
development program, make a total budget of
about $800,000 for Fiscal Year '72-'73.
The first priorities are the expansion of the
community noise survey and a traffic noise
survey. Three additional projects are
underway; a construction noise survey, a study
to explore and assess alternatives to
automobile horn noise, and a siren noise study.
The city is pressed to meet its most urgent
financial needs, and the Noise Bureau cannot
realize its program fully within current
budgetary limits. A federal program of
development, establishment and maintenance
grants for local noise abatement programs is
urgently needed. A system of matching funds is
not satisfactory since the city cannot
guarantee to match it.
Another area where federal assistance is
essential is that of mass transit. The subway
system in New York is old and noisy. The City
does not have and is not going to have the
estimated millions of dollars needed for a
comprehensive program of subway noise
abatement. A program of federal noise
abatement grants for mass transit, either out
of an expanded Office of Noise Abatement or out
of the Department of Transportation is needed.
In addition to establishing a system of grants
for local noise abatement programs, there are
a number of ways in which the federal
government can play a powerful role in noise
abatement. First, the government should
promote the use of quieter equipment by
incorporating noise specifications into all of
its vast purchasing programs. Second, all
federally contracted construction projects
should be required to meet specific noise
standards. Third, the federal government
should make funds available for demonstration
projects to promote advancement of noise
abatement technology. Last, more research is
needed in the area of health effects of noise.
The Federal government must also play a role
in jurisdiction. Some of the major sources of
noise pollution in urban areas are not
susceptible of solution on the municipal level.
The most obvious is aircraft noise. The noise
problem created in urban areas by motor
vehicles illustrates an important aspect of the
Federal noise abatement role. New York City is
attempting to regulate this source in its
Noise Control Code. The most effective way to
stop noise is at the source and Federal limits
on a I I classes of motor vehicles would be
welcome. It is essential that the Federal
government set specific noise limits wherever
possible, but states and municipalities must
be left free to set more stringent standards
if necessary. Noise pollution is ultimately a
I oca I p rob I em.
Noise in our cities can no longer be ignored.
It is a problem ranging in seriousness with
pollution of air and water. It must be
attacked vigorously by a I I levels of
government, by industry, and by the individual
citi zen.
41
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ABSTRACTS
NOISE SUBJECT FIELD AND SCOPE NOTES
As an aid to the reader with specialized interests, abstracts of journal
articles, reports and other sources have been grouped by subject area.
The twelve categories used are listed and briefly described below.
However, there is often considerable overlap, and related categories,
as well as the subject index, should also be consulted.
1. EMISSION AND SUPPRESSION RESEARCH AND DEVELOPMENT
Phenomenology of noise generation, transmission and suppression,
including experimental data and theoretical studies.
2. PHYSIOLOGICAL EFFECTS
Aural and non-aural effects: e. g. , hearing loss, circulatory and
cardio-vascular effects, sensory perception, neural effects, etc.
3. PSYCHOLOGICAL AND SOCIOLOGICAL EFFECTS
Effect of noise on sleep and work patterns and other human
activities; personal attitudes toward noise; effect of noise on
learning, convalescence, etc.
4. ECONOMIC ASPECTS
Costs of noise abatement and control; costs of non-abated noise,
impact on trade both domestic and foreign.
5. BUILDING ACOUSTICS AND NOISE CONTROL
Use of construction materials and their installation, such as
techniques for isolating and decoupling electrical outlets, plumbing
and air flow ducts from partitions; reduction of impact and airborne
noise transmission.
6. NOISE MEASUREMENT
Units, instrumentation, techniques, scales, weighting networks,
recording and monitoring systems, data processing systems.
42
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7. PLANNING, DESIGN AND ARCHITECTURAL SITING
City planning, industrial plant layout and design, land use, airport
and highway siting, land development, zoning.
8. LEGISLATION, STANDARDS, LEGAL PRECEDENTS
Laws, codes, zoning ordinances, statutes, standing of parties,
jurisdiction of courts, court's decisions, etc.
9. ENFORCEMENT
Enforcement techniques and experience, including training, equip-
ment costs, staffing.
10. PROGRAM, PLANNING, AND BUDGET
Federal, state, and local policy decisions; budget information;
program status, program descriptions.
11. NOISE MEASUREMENT DATA
Noise emissions generated by equipment or activities; attenuation
levels for particular materials, time histories, octave band
analysis.
12. EDUCATIONAL AND GENERAL
Textbooks, university curricula, general education articles, mass
media coverage, popular brochures, and other popular awareness
materials.
43
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01-001
EMISSIONS SUPPRESSION
01-001
Flanagan, W.
Automotive Engineering
RECENT STUDIES GIVE UNIFIED PICTURE OF TIRE
NOISE
Automotive Engineering
Vol 80 No 4:15-19, 1971
Data establishing truck tires as a noise
source are presented. Tires fall into three
clearly defined categories as noise producers:
pocket re-tread, cross-bar, and circumferential
rib. Loudest are older recapped tires,
particularly the pocket retread. Lateral
elements of cross lug tires may wear into
pockets and produce noise the same way, but most
noise is generated by the gripping and releasing
action of the tread elements during traction.
The quietest tires are rib designs.
Rankings within tire noise categories may
shift as the road surface changes from concrete
to asphalt. Sound levels rise with increasing
speed on all tires, but at slightly different
rates. The National Bureau of Standards (NBS)
reports an average 3 dBA increase per 10 mph.
At lower speeds, down to 20 mph, total truck
noise changes faster, 5-10 dBA per 10 mph.
NBS reports that loudness (peak dBA reading)
produced by most tires rises 3-5 dBA when
the tire is half used. Some tire types make
more noise fully-worn than when half-worn.
NBS data indicate that the difference in peak
sound level between new and ha If-worn states
is greater on concrete than on asphalt,
depending on the frictional properties of the
road. Theories on the effect of wear seem
to agree that pressure distribution in the
contract patch may be an important variable.
Most tires wear first in the middle, trans-
ferring weight to the outer edges of the
patch.
Higher forces on tread elements make for more
noise, regardless of where the force comes
from. Sound level differences due to load in
the NBS data are only 1-3 dBA for rib tires,
but increase significantly for cross bar
(6-8 dB) and pocket retread tires (4-8 dB).
Inflation pressure has no definite effect.
The tire industry has not subscribed to dBA
exclusively because of its deficiency in
measuring tonality. Subjective comparisons
point to tonality and persistence as major
factors of annoyance.
High hysteresis rubbers could reduce noise
by damping the snap actions of tread elements,
but the energy would go into heat instead of
sound. Because of the thickness and low
thermal conductivity of truck tires, heat
generation creates high temperatures and has a
deleterious influence on durability and safety.
01-002
Fosca, V.
Biborosch, L.
Popped, N.
Technisches Institut, Fakultaet Fuer Bauwesen,
Jassy /Rumania/
Technische Hochschule in Jassy, Str. Karl Marx
No. 38, lasi, R. S. Romania
INVESTIGATION OF SOME TRAFFIC NOISE
RELATIONSHIPS
Untersuchung Einiger
StrassenIaermabhaengigkeiten
Laermbekaempfung
No 2/3:46-48, 1970
Investigations of traffic noise in Jassy,
Rumania, were conducted. The results showed
that the noise levels exceeded regulations
even for the low density traffic. Measurements
were taken at 7 to 10 m from vehicles travelling
at 30-50 Km/h. The results were as follows:
Type of Veh icle
Buses with diesel engine
Trucks with internal
combustion engine
Automobi les
Street-cars
Level in dBA
91-93
81-84
80-82
82-85
The measurements were conducted on 3 different
types of main arteries, those with greenery,
close, and distant house-fronts. The first
group had tall trees on the side-walk area
between the street and houses, group I I
had some lawn and sparse shrubery and group
III had closely congested houses and narrower
streets.
Group I and II showed a small variance of 6 dB
from group III. Frequencies play an important
part especially in the ratio of the echo time.
In order to attain considerable noise reduction
in the lowest frequency range screening by
means of walls or types of building can be
used.
44
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01-003
EMISSIONS SUPPRESSION
01-003
Rainey, J . T.
Carrier Corp., Syracuse, NY
Research Division, Zip 13201
EVALUATION OF NOISE CONTROL TECHNIQUES FOR
QUIETING PLATE FIN PRESSES
Syracuse, Carrier, 21 p.
Methods for quieting a plate fin press when
machine enclosures prove to be infeasible are
examined.
The die areas were found to be the greatest
contribufors to the noise generated by plate fin
presses. It was also established that most
of this noise was generated by metal to metal
contact of the traveling pads and stationary
pad keepers.
A reduction of 3-4 dBA was achieved by imposing
a resilient material between the normally metal
to metal contact areas of the traveling
stripper pads and the stationary pad keepers.
The application of the resilient material
using urethane rubber requires less than a work-
day for each machine, has been shown to last
for at least a year, and does not affect
the production rate of the machine.
When all of the presses are running the noise
levels produced at the operator's locations can
be expected to be about 3 dBA above the noise
level produced by a single press. The noise
reduction achieved by using impact strips
may not, however, be enough to meet the 8 hour
90 dBA I imit set by the Federal Occupational
Safety and Health Act. Preliminary tests of
an additional noise reduction modification,
namely that of splitting the traveling pads,
show promise for reducing the noise even
further; however, the specific benefits of
this modification must await further testing.
01-004
Wiedefeld, J.
CONSTRUCTION TECHNOLOGY FOR ABATEMENT OF
AVIATION NOISE IN THE RESIDENTIAL AREAS
AROUND THE DUESSELDORF AIRPORT. PART 2
Bautechnische Massnahmen zur Bekaempfung
des Fluglaerms in den Besiedelten Wohngebieten
des Flughafens Duesseldorf. Teil 2
Kampf Dem Laerm
Vol 18 No 1:13-17, 1971
Part 2 of this article describes the tech'iicnl
measures for the abatemenr of aviation noise
in a Catholic elementary schoci GuesseIdorf-
Lohhausen, in the vicinity of The Duesseldort
Ai rport.
Acoustical measurement taken by the Max-Planck
Institute gave values of 105 dB ana 110 dB
for jet aircraft.
The noise level in the classrooms facing the
west and with closed windows was 89-98 dB,
Double box-windows were installed and quality
materials were used in ("he construction.
After the windows were installed the sound
level was lowered at least 15 dB.
A 2 meter wide and 1.40 meter deep outer
chamber (ante-room) consisting of bricks and
mineral fiber tiles was constructed on both
sides of tne entrance with a soffit over ~ne
door. A double layered door consisting o^
50 mm thick metal frame and d 12 mm triicK
wired plate glass, the inner door is
similarly constructed, was installer1.
Because of the frequency of starting and
landing jet planes the east and north side
of the corridors were reinforced with an
outer sound-absorbing wall.
With these new sound-absorbing me=ns the
instruction in the classrooms could be
carried out without any disturbance or
i nterrupt ion.
Bolt, Beranek, and Newman, Inc.,
Cambridge, MA
NOISE OF PILE DRIVING EQUIPMENT
At: Acoustical Society of America Meeting,
Washington, APR 20-22, 1971
Cambridge, BolT Beranek, and Newman, 1971, 9p.
The problems of measurement analysis and
evaluation of pile driving equipment is
d iscussed.
Impact hammers and vibratory drivers comprise
the two main categories of pile drivers.
Impact hammers have either steam pressure or
diesel engines, and noise is generated by both
the power source and by the impact of the hammer
and pile.
45
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01-006
EMISSIONS SUPPRESSION
The vioratory hammers are either low frequency
(30 Hz) with electric engines, or high frequency
(50-150 Hz), powered by two unmuffled gas
engines.
Comparisons of noise spectra generated by 3
types ot pile drivers are presented in Figure
1. Total sound energy varies with blows per
minute.
Comparison of Noise Levels of Different Pile Drivers
A STEAM. 15" PIPE CAPPED
BOSTON CITY HOSPITAL
O DIESEL'14" PIPE HOLLOW
PROVIDENCE CIVIC CENTER
O SONIC. 14" PIPE HOLLOW
HARVARD CEO-CHEMICAL
STEAM
DIESEL
ALL PEAK LEVELS
(SLOW SCALE)
NORMALIZED TO 50'
3L5
63 125 230 500 1000 2000 4000 8000 16,000 3I.5OO
OCTAVE BAND CENTER FREQUENCIES IN Hz
Diesels are best suited for hard soils, whereas
steam hammers are best used on soft soils.
Diesels, diesel crews, and fuel are more
economical than steam. A sonic driver costs
about 2-2i times as much as steam equipment.
Much more research is necessary in the field of
construction equipment such as pile drivers;
presently the state of economy dictates the
choice of equipment.
01-006
Priede T.
Southampton Univ. /England/
ROAD TRAFFIC NOISE-ITS ORIGINS AND CONTROL
In: Janson, P. 6., Conferences in Connection
with the International Air Pollution Control
and Noise Abatement Exhibition, Joenkoeping,
Sweden, SEPT 1-6, 1971
Joenkoeping, Sweden, 1971, 525p. (p. 7:12-7:30)
A comprehensive study of the relation between
subjective rating of noise emitted by motor
vehicles and the objective measurements with
a sound level meter has been made. Subjects
were asked to rate the noises which were
presented to them according to a six-point
rating scale by verbal description. It can be
concluded that a level close to 80 dBA fairly
represents the demacration lire between
"acceptable" and "noisy" for most vehicles
The range of measured dBA levels for various
types of vehicles were: heavy commercial
vehicles, 88-92; light commercial vehicles,
79-91; cars 77-91. The legislated standards
in the United Kingdom for these vehicles are
89, 85 and 84 respectively. Tests indicate
that truck noise is predominantly controlled
by the power unit. This increase of noise
is 11 dBA per doubling the speed. In
gasoline cars a doubling of speed results in
an increase of 15 dBA.
It can be concluded that noise is generally
independent of the volume of work done per
unit time or horsepower. The main criteria
which determines the noise is the operational
speed or how short the time interval is
within the operation of one cycle of events
is being performed by the machine.
Transmission noise ranges from 75-85 dBA
and seems dependent upon engine vibration.
Road conditions have greatest effect on tire
noise, an 8-10 dBA increase in noise is
noticed if the road surface is wet and a 3-5
dBA increase if it is coarse rather than
smooth.
A quieter vehicle can only be achieved by
close co-operation between the vehicle and
engine designer and the following essential
aims should be observed. First, design a
vehicle giving adequate attenuation of
the engine noise. Also appropriate choice
of engine design parameters is necessary
including:
1) limitation of the maximum engine rated
speed;
2) limitation of engine cylinder capacity,
3) increase of engine load even to four
times the values at present used,
and, finally, a quieter engine structure.
Methods of rating noise and noise as a
function of engine speed are also discussed.
01-007
Warren, C. H.
Royal Aircraft Establishment,
Farnborough /England/
Structures Dept.
SONIC BOOM EXPOSURE EFFECTS I.2: THE SONIC BOOM
GENERATION AND PROPAGATION
Journal of Sound and Vibration
Vol 20 No 4:484-497, 1972
46
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01-008
EMISSIONS SUPPRESSION
A description is given of the technical
aspects of the generation and propagation
of sonic booms in order to provide the
background for an understanding of their
effects on animate and inanimate objects.
Any aircraft in flight creates a pressure
field in the surrounding air. At
supersonic flight speeds the pressure
disturbances are concentrated in waves.
The pressure disturbances in these waves
decrease at roughly the inverse first power
of the distance from the aircraft. Because
of this lower intensity decrease with
distance as compared to subsonic aircraft, the
pressure disturbances made by supersonic
aircraft are experienced at larger distances
from the aircraft. Moreover, the sharp
variations in pressure make the disturbances
audible as the sonic boom.
Field work was carried out from August to
early October, 1970, in eastern Ontario &
western Quebec.
01-008
Myles, D. V.
Hirvonen, R.
Embleton, T. F.
National Research CounciI of Canada,
Ottawa /Ontario/
AN ACOUSTICAL STUDY OF MACHINERY ON LOGGING
OPERATIONS IN EASTERN CANADA
Ontario, National Research Council of Canada,
APR, 1971, 41 p.
A survey concerning noise from logging
machinery and the effect of the forest in
reducing that noise was carried out following a
meeting held in Ottawa in April, 1970, that was
attended by representatives from the Canadian
Forestry Service, National Research Council,
Ontario Department of Lands and Forests, Pulp
and Paper Research Institute of Canada, Ontario
Forest Industries Association, and the
Canadian Pulp and Paper Association.
The survey had the twofold purpose ofobtaining
a statistical picture of: 1) the noise
produced from typical logging operations and
from the different types of machines on them;
and 2) the influence of normal forest conditions
on the propagation & attenuation of sound from
logging operations.
This approach was expected to produce results
from which preliminary conditions could be drawn
concerning: 1) the noise characteristics of
common logging machinery; 2) the risk of hearing
damage to machine operators; and 3) the
propagation of sound in the forest with respect
to other forest users.
01-009
SOUND-DEADENING IN SOIL PIPE SYSTEMS
Compressed Air Magazine
Vol 76 No 11:18, 1971
A 2-year study conducted by Polysonics
Acoustical Engineers demonstrated neoprene
synthetic rubber's role in alleviating noise
in soil pipe systems. Random vibration.
sources were set up and neoprene was applied
in various axes to the pipe being measured.
Measurements of cumulative vibration drops
over a large number of joints, as well as the
per-joint reduction, were made. Polysonics
determined that in a cast iron soil pipe
system, use of neoprene gaskets provides a
positive reduction in vibration, and hence
noise, at each joint. (Soil pipe systems
made of cast iron are quietest because of
thei r heavy mass.)
A neoprene compression gasket was found to
provide vibration drops as high as 20 dB per
joint at the higher frequencies. A Cl No-Hub
neoprene gasket with stainless steel coupling
provides vibration drops of as much as 11 dB
per joint at higher frequences. Both types
prevent direct metaI-to-metal contact at joints.
Field tests conducted in Washington, DC
high-rises showed even greater vibration drops
per joint than in the lab tests.
47
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01-010
EMISSION & SUPPRESSION
01-010
Goncharenko, V. P.
Steklotarno-lzolyatornyy Zavod, Ordzhonikidze
/USSR/
ON THE REDUCTION OF AUTOMOBILE AND TRACTOR NOISE
K Voprosu o Snizhenfi Shuma Automobiley i
Traktorov
Gigiyena Truda i Professional'nyye Zabolevaniya
Vol 14 No 1:46-47, 1971
01-011
Bobin, Ye. V.
Leningradskiy Institut Inzhenerov
Zheleznodorozhnogo Transporta im. V. N.
Obraztsova, Leningrad /USSR/
NOISE REDUCTION FOR RAILWAY TRAFFIC AND
RHEOSTAT TESTS OF DIESEL LOCOMOTIVES
0 Snizhenii Shuma pri Dvizhenii Poyezdov i
Reostatnykh Ispytaniyakh Teplovozov
Vol 34 No 1:94-97, 1969
Soviet sound pressure meters with frequency
analyzers were employed to measure noise
levels at a 7 meter distance emitted from
vehicles travelling at speeds of 19 to 25 mph.
The range of readings was 74 to 109 dB.
The total sound pressure level (SPL)
for trucks with frequency range predominante ly
351-800 Hz, was 89-107 dB, while for light
weight cars it was 74-103 dB with an average of
88 dB. The ''Belorus" tractor ranged from
78-101 dB, while heavier tractors and
bulldozers produced readings of 95-105 dB at
frequencies above 800 Hz. In all cases the
existing standards were exceeded. Vehicle
interior readings were 70-80 dB (800 Hz) at
rest and 76-89 dB in motion.
To reduce automobile and tractor noise,
dynamic balancing is required for the engine,
the gear box, the Cardan shafts, the fan,
the divided axle, the wheels and the tires.
Elastomettalic coatings made of perforated
materials must be more widely introduced, along
with antivibration coatings and soundproofing
shields. Damping devices must be improved
and put into wide use. Impacting metal shafts,
gears, etc. need to be replaced by plastics;
hydraulic and pneumatic suspensions should
phase out springs; straight-toothed gears should
be replaced with spiral helical or worm gears.
Manufacturing tolerances must be cut to a
minimum to reduce joint clearances and
prevent frictional noise. The bearing surfaces
of joints must be fully protected by lubricants
and rocker bearings must be replaced by
slide bearings and noise and vibration
insulating coverings. Power transmission
can be damped by flexible couplings and housing
openings for passage of shafts, etc. should
be equipped with mufflers in the form of pipes
whose interior is faced with sound-absorbent
materia Is.
Soviet regulations prescribe the distances that
residential areas must be located from
railway tracks, depots and rheostat-test areas.
Recent measurements have shown that the
standards for residential noise in the vicinity
of such railway facilities are universally
violated, although distances in many cases are
in keeping with regulations.
Realistically, means must be found to attenuate
the noise, both by insulation at the source
and by screening along the sound path. The
protective effect of brick shields built in
Lvov is cited.
The brick shield was built 15 meters high
18 meters from the railroad tracks and 72
meters from the housing it was to shield.
It reduced the noise levels in the housing
area by 20 dB, or a factor of four in terms
of subjective loudness, enabling the
regulations to be met.
01-012
Doak, P. E.
May, D. N.
Southampton Univ. /England/
Institute of Sound & Vibration Research,
Southampton S09 5NH
LETTER TO THE EDITOR: EFFECTS OF LOUVRES ON
THE NOISE OF AN AXIAL FLOW FAN
Journal of Sound and Vibration
Vol 15 No 3:421-424, 1971
The effect on the sound field of axial flow
fans of louvers positioned across their
intakes was studies in light of design of
lift fans for vertical take-off aircraft
and ventilation systems.
48
-------
EMISSIONS SUPPRESSION
01-013
A rig configuration was chosen which was
typical ot ire levels wiit and without
tr.t, • '•,[-.
Measurements were made of overall sound pressure
level for rotor speeds ot 6000 and 12000 rev/min
at ten degree intervals of microphone position
between -90 degrees and +30 degrees. This
wj; performed for ten lonve; angles from
U- rr-pc "I * 9>"' ^onrpe-
•j vjt ^r^eb i., y^ oCgrc-L-b.
/" compjiib^n of tne airflow measurements and
and tne °es.ri+s iridi a^oo Mat the increase in
sound pi-assure level whori the louvers were
tilted about 40 degrees occurred when the
louvers begfii t,- navr •, s|v lirig t,ffe^t on the
flow to rhc rotor. Tri --'fe-.t bt;came
more marked as the icuv< r angle increased unti I
a point was reached .-' - jt 65 degrees where
the opposing effects ' " reduced mean flow and
acoustic blockage bec.!.i»e effectively egual,
and beyond 65 degrees *"e cmount of noise
r art i a ted f rorr 'he i n ' ^ .' dec. rfectscd .
The overall noise fielj v^as found to be
roughly non~directionat for all louver
angles, but the distr.'.,i on in angle of the
radiated noise at the i >, i i d-octave band
containing the blade "ossage frequency was
found to deviate i r< - ~ ather irreoular
manner.
01-013
Swetnam, G. F.
Willingham, F. L.
MITRh Corp., McLean, VA
1820 Do I ley Madison Blvd.,
Zip 22101
EVALUATION OF CITY TRANSIT BUS "EIP" KITS TO
REDUCE ENGINE SMOKE, ODOR, NOXIOUS EMISSIONS
AND NOISE
The General Motors' Environmental Improvement
Program (EIP) re'ruiit was desirineo to be
installed c r CM city transit bus---, vjit:1 H «o
cycle diest-,1 engines for the reduction ot lit
emissions and nois-?. Field testing ha-a
shown that EIP kiis, propertlv installaJ and
maintained, reduce visible smoke, odor,
noxious emissions or hyar ^carbon? a'ld
carbon monoxide and (slightly1' noise
levels inside the uus. Mo/j^v,-r, e>i,, , ~*(
noise was not reduced and eve.1 in;'eased
under certain circumstances. Better noise
reduction performance might ne jttain^t, with
no worsening of other performance ^aramelers,
if certain kit components were redesigned.
The kit cons i s ted ot: ( 1 ) ,e ^ r 1 oN ' JL-
injectors, (2) vertical, aspirated exhaust
stack, (3) muffled air induction system, (4)
energy abso-bing engine mount-, (:•) mutr'i-
incorporai ,.ig a ^.atat/fir reacior, as we > ' as
chariges in operation: revised f jel injector
timing, higher t ransmi . j ior> t.Mt speed
setting, ana use ot Number ! t die csiesu1
fuel.
Bus noise is transmitted to the inferior
through engine irountings and various ducts.
Exterior noise is radiated from exhaust and
intake openirg=, the air conditioner arid
the cooling tan. The EIP kit's improved
motor mounts and air intake muffling reduced
inferior noise levels slightly. The mounts
used ji-,01 |iriu-:i rubber insul riio', ' t f ween the
eno/ ' cradle ^nd The coach ohas. 's,
observations showed ^ha' sorut- of the i
had soon deteriorated VH rn s&r"v «'\. i^
suggesting that redesign may be --.'G.I
One rxd^-r. rx:^rior roise i^as 'l 't r-.Uu.'f-d /jas
that the exriju?t stack and ..araiylic muffler
treatments were chiefly aimeo a~ abating
ail po i 1 u i i - .n . Since ^he ra'ulytiC rnufiler
was not par;icuiarl/ effective toward that
purpose, it might well be replaced with a
muffler thaT was rror-e effective acoustically.
The o+her reasr;n rhaf extei ior noise Tended
to increase was the higher shift speeds
needed to reduce the smoke produced at shift
points.
49
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01-014
EMISSIONS SUPPRESSION
GM first assembled the kits in late 1969.
Of 53,000 transit buses in the national
fleet, the majority are of 6MV manufacture.
The EIP kit or at least its most effective
component, the LSN injector, could be fitted
in its entirety to the 24,000 "new look"
buses produced since 1959. Buses fitted with
EIP kits were tested in San Francisco, San
Antonio, and Washington, DC, during
1970-71.
A bus presently in service could be fitted
with an EIP kit for about $2650, parts and
labor. Including the kit at the factory in a
new bus would cost about $500-550.
01-014
Myles, D. V.
Hirvonen, R.
Embleton, T. F.
National Research Council of Canada,
Ottawa /Ontario/
ON: NOISE MEASUREMENTS OF LOGGING MACHINERY
IN THE FOREST
In: Myles, D., An Acoustical Study of Machinery
on Logging Operations in Eastern Canada
Ontario, National Research Council of Canada
APR, 1971 41p. (p. 17-41)
Noise measurements of logging machinery in the
forest and a few suggestions to reduce noise
that is recreationally intrusive are presented.
Sound level readings were taken of about 130
different logging operation machines. Skidder's
and chain saws are the most common noise
sources. Readings were taken at the operator's
ear for both loaded and empty machines at 15 and
50 feet for eight frequency bands (63 to 8,000
Hz).
The maximum distances at which the noise from
logging operation was audible were also
determined for several sites at upwind, cross
wind and downwind. Temperature, humidity, wind
speed and direction were noted at all times,
notes on topography and forest cover were kept,
and ambient noise levels were measured as often
as practicable, using Bruel and Kjaer portable
sound leve-l meters.
The number of machines producing various
sound levels is illustrated for all skidders and
chainsaws, by histograms of the measurements
taken in dBA (Fig. 1) and dBC (Fig 2). For sound
energy following the inverse square law
the levels should be 10dB lower at 50 ft
than 15 ft, but skidder noise decreases by only
6 dB because of the machine's size. On rough
terrain, skidders produced more noise when empty
than when full. For the noisiest \Q% of fhe
chain-saw operations the sound levels ranged
115-119 dBA. There was great variation
between chain saws of the same make and model.
0 10
Scale of No. of Machines
120
110
90
80
70S..
"Skidd.
Sawi
at operator's ear at \5 feet at 50 feet
FIGURE 1.
0 10
Scale of No. of Machines
110
100
90
80
70
Skidde
Saws Skiddtrs
Saws
at operator's ear at 15 feet at 50 feet
FIGURE 2.
Noise spectra measured at 50 feet were averaged
and plotted for chain saws, skidders, loaders
and logalls (Fig. 3) According to the inverse-
square law, the noise levels should decrease
22.5 dB between 50 feet and 10 chains (660
feet). However, the decrease was actually about
32 dB in the low frequency octave bands and
42 dB in the high frequency octave bands.
This additional reduction is probably due
to forest absorption and the average of many
different atmospheric conditions.
50
-------
EMISSIONS SUPPRESSION
01-015
Companion of voriom moenmct
01 M II
63 125 350 500 1000 2000 4000 8000
FREQUENCY-Hi
01-015
Myles, D. V.
Hi rvonen, R.
Embleton, T. F.
National Research CounciI of Canada,
Ottawa /Ontario/
PROPAGATION OF SOUND WAVES IN FORESTS
In: Myles, D., An Acoustical Study of
Machinery on Logging Operations in
Eastern Canada
Ontario, National Research Council of Canada
APR, 1971, 41p. (p. 2-17)
The human ear can certainly distinguish
machinery noise from background noise in the
forest, even when the machinery noise is less
than the ambient background noise. For this
reason a human measured (rather than machine
measured) approach was applied to the
problem of intrusiveness of noise on a
recreational use of the forest. In the average
situation, the chain saw noise could be
heard to a distance of 115 chains (1.43 miles).
Skidder noise could be heard to a distance of
116 chains (1.45 miles).
Particular situations can differ markedly from
the average. On s1 i I I mornings logging
operations could be clearly heard for distances
of over 2 mi les. Noise from a skidder working
across a bay registered 58 dBA at a distance
of 0.9 miles. On some occasions in hilly
country, noise was not heard much beyond 0.5
mile, but from a hill top a slasher was heard
2.25 miles away. On a windless, misty day,
chain saws could be heard at 2.25 miles in
fairly flat country, but in a 5 mph breeze
the same operation was inaudible beyond 0.7
mile upw i nd .
When considering the propagation of sound over
long distances, any reduction at the noise
source would help reduce the distance that
such noise would travel. A 6 dB reduction can
be obtained by muffling and will reduce by 40%
the distance at which it can be heard. Further
improvements would require an attack on
engine noises other than exhaust.
To prevent intrusiveness of noise to campers,
it is concluded that logging operations should
not be permitted closer than one mile from the
location being used.
The propagation of sound waves in forests is
investigated as acoustical background to a
Canadian survey on noise from logging
equipment and the effect of the forest in
reducing that noise.
When a source radiates noise outdoors, the
sound levels naturally decrease with distance.
At distances greater than four times its
average linear dimension (the 'far field") sound
energy radiates according to the inverse-square
law and decreases by 6 dB for each doubling of
the distance from the noise source. The
deviation from this law grows greater with
higher frequencies and is very dependent
on humidity and temperature, as shown.
Table 1: Decrease of sound-pressure levels due
to energy absorption in air by molecular
processes, stated in dB per mile.
Relative Temperature 1000 Hz 2000 4000 6300
humidity and below Hz Hz Hz
% oF
30
50
70
59
68
77
86
50
68
77
86
50
68
77
86
2
2
2
2
2
2
2
2
2
2
2
2
25
21
20
19
17
17
17
16
15
15
15
14
85
66
54
49
50
42
41
41
39
37
37
36
185
147
120
99
110
88
77
75
79
70
68
67
Sound propagation through extensive forests has
a reasonable attenuation of 2 dB per 100 feet.
The thickness of the forest affects sound
propagation, but reaches a plateau, regardless
of density, at about 10 dB -for all frequencies.
This value fluctuates due to wind and other
factors, so it is not constantly accurate.
51
-------
01-016
EMISSION & SUPPRESSION
Wind primarily redistributes the sound energy
in different directions. When the gradient of
the wind velocity is positive (downwind from
the source), sound energy is refracted downwards.
Likewise, as temperature increases with
increasing height (positive gradient), it
refracts sound energy downwards in all directions
increasing the sound level pressure. Wind also
causes leaf rustling on trees. There are two
species of poplar and birch which generate
noise at levels as high as 40 dB at wind speeds
of 5 mph.
The measurements discussed here apply to the
intrusion of noise from woodland operations
upon those using the woods for recreational
purposes. Most criteria for intrusiveness
are based on typical urban environments, and
very little has been done on forest noise. In
places such as concert halls, however, criteria
for noise are set, and at very low levels. It
is assumed that these criteria will be the
same for forest noise.
Such criteria are expressed in terms of Noise
Criteria (NO curves, which specify noise levels
allowed at each octave band. The annoyance of
a measured noise is found by plotting levels
superimposed on the NC curves. In these terms,
the background noise in concert halls should
not exceed NC 15 to NC 20. However, this
applies to continuous noise, and time-varying
noise such as those produced by a chainsaw
would lower the criteria to NC 10-15.
The threshold of hearing (12 dB lower than 10)
could also be used as a criterion for forest
noise, although this assumes that there are no
masking noises in the vicinity of the listener.
01-016
POLYURETHANE FOAM CONTROLS MACHINE NOISE
Sound and Vibration
Vol 5 No 7:12, JUL, 1971
The noise from high-speed computer printers
has been lowered from 80 to 55 dB using a
sound absorption material made of compressed
polyurethance foam. The major source of noise
printers is a large number of rapid-fire
hammers—132 or more—that print out up to
1250 I ines per minutp.
The cornp.,. ^ t-jjm is made by applying heat
and pressure to the original material until
its dimensions are reduced Dy the desired
ratio. This process changes the internal
structure of the foam, improving its sound
absorbing properties. In the computer printer
application, the brand used was Scottfelt
and the printer was the RCA 70/242-30. The
original thickness of the foam layers was
attached to interior metal surfaces of the
printers using adhesive, as well as installed
on a sound baffle near a point where cooling
air entered the printer. Other materials
considered, but not used included glass fiber
and closed eel I foam.
Other applications of the material have
included tractor engine compartments and gas
turbine power plants, both stationary and
ai rcraft types.
01-017
Jackson, C. E.
Grimster, W. F.
West I and Helicopters, Ltd.,
Yeovi I /England/
HUMAN ASPECTS OF VIBRATION AND NOISE IN
HELICOPTERS
Journal of Sound and Vibration
Vol 20 No 4:343-351, 1972
Types and sources of helicopter vibration,
methods of vibration testing and monitoring,
methods of vibration reduction, and internal
and external noise are discussed and information
is given on results of internal cabin noise
reduction.
The fundamental mechanics of the helicopter,
involving a number of rotating components, make
the machine subject to vibration and noise. The
prime sources of excitation are the main rotor,
the transmission system, the tail rotor and the
engine. This frequency range of 20 to 15,000
Hz encompasses main and tail rotor harmonics,
gearbox noise, noise generated by engine
components and aerodynamical Iy-produced broad-
band noise.
Externally, the predominant noise is generated
aerodynamically by the main and tail rotors.
Harmonics of the main rotor blade passing
frequency occur at the low frequency end of
the audio range. Tail rotor rotational
harmonics, broad-band noise from the main
rotor and gear meshing noise dominate the
mid-frequency region and engine compressor
orders exist above about 10 kHz.
The subjectively dominant internal noise sources
are transmission (gear meshing) orders.
52
-------
01-018
EMISSION & SUPPRESSION
If the helicopter is to fulfill future civil
requirements it will be necessary to reduce
cabin noise further. Although the internal
noise in military helicopters is considerable
the crew wear helmets which attenuate the level
at the ear.
Noise can be transmitted to the cockpit and
cabin as airborne noise and/or as structure
borne vibration. Present soundproofing schemes
consist of lining the cabin with an absorbent
material such as fiberglass. The whole surface
area of the cabin is treated.
Considerable reductions in cabin noise levels
have been obtained. The mid and upper audio
frequency region of the noise is subjectively
most important and in this area the greatest
reductions are apparent.
Future investigations are planned to optimize
soundproofing, in an attempt to reduce the noise
levels even further.
It appears that the subjective effects of noise
and vibration are additive, and thus the
helicopter is a vehicle on which combined field
and laboratory environmental studies should be
d i rected.
FriqueneylHi)
Figure 1 Helicopter noise sources.
HUMAN AS?EC15 OF HELICOPTER VIBRATION
: 80OO 6000
Oetov* centre frequency (Hi)
Figure 2. Effect of cabin soundproofing
01-018
Gregoire, M. C.
Streckenbach, J. M.
Boeing Co., Seattle, WA
Commercial Airplane Group
P. 0. Box 3707, Zip 98124
EFFECTS OF AIRCRAFT OPERATION ON COMMUNITY NOISE
Seattle, Boeing, JUN, 1971, 10 p.
Industry and government studies in
response to airlines, airframe and engine
manufacturers, and local airport authorities
to reduce aircraft generated noise in airport
communities are reported.
Three general areas of community noise
improvement are summarized as:
1) Reduction of the noise at its source by
quieting the engine installations on the
aircraft
2) Changes in land utilization in airport
communities
3) Changes in regulatory and operational
procedures in the vicinity of airports.
Considerable work now being done in industry and
government programs is related to examining
means of retrofitting the existing fleet of
commercial fanjet transport aircraft to
significantly reduce their community noise
levels. The magnitude of noise reduction
attained is closely related to technical
feasibility and to the economics of airplane
modification and operation.
Both Federal and local agencies are continuing
to study the possibilities of community noise
relief through better land utilization. Such
studies encompass the subjects of improved
planning for new airports, tightened building
codes and zoning restrictions, and revised land
utilization around existing airports. Economics
is an important and unavoidable consideration in
land utilization studies.
Noise reduction through operational procedures
offers much relief to the community at
relatively little cost, without affecting safety.
These procedures include Federal and local
regulations and operating procedures available
to the ai rli nes.
Holding and maneuver attitudes can be raised
by Federal and local regulation. Traffic
patterns and routes can be optimized over less
populated areas. If glide slopes are steepened
by i degree, significant noise reduction will
occur. Finally, the glide slope intercept
altitude can be raised. If all of these points
were accomplished. Federal and local regulation
would be responsible for a good deal of noise
reduction.
53
-------
01-019
EMISSIONS SUPPRESSION
Operational procedures available to the airlines
themselves could also effect changes in aircraft
noise levels. Noise can be reduced considerably
by delaying landing gear and flap extension.
Two-segment approaches, or intercepting the
final glide slope from a steep descent, will
keep aircraft at a high level over the community,
and the noise level will remain low. Flap
position during approach and landing could be
set at a lesser angle, producing less noise.
This would require additional runway yardage.
Take-off procedures could be modified by
implementing a power cutback at an acceptable
aItitude.
2345
DIStANCE FROM THRESHOLD (NMD
FIGURE 1. Noise Footprint Comparisons of
Two-Segment Approaches
01-019
Kugler, B. A.
Anderson, 6. S.
Bolt, Beranek, and Newman, Inc.,
Canoga Park, CA
Zip 91303
AUTOMOTIVE NOISE ENVIRONMENTAL IMPACT
AND CONTROL
At: Highway Research Board Annual Meeting,
Ingenjoersvetenskapsakademien, Sweden, 1972
Canoga Park, CA, Bolt, Beranek, and Newman,
1972, 30p.
The units used to describe automotive noise,
which is the most widespread and important
contributor of urban noise, the current criteria
used in assessing the impact-of traffic noise on
people, various automotive sources that combine
to create traffic noise, and control of motor
vehicle noise are discussed.
The effects of automotive noise on people can
be divided into the subjective effects of
annoyance, nuisance, and dissatisfaction and
interference with tasks such as sleep, speech
and learning. Interference with speech and T.V.
listening is the predominant complaint against
automotive noise and interference with sleep is
also often cited. In describing subjective
response, measurements of time average noise
levels and the magnitude and frequency of the
occurrence of peak noise levels are important.
In conjunction with these points, criteria
specifying maximum noise levels to which
people will agree have been derived. One
method, known as the statistical time
distribution, identifies each noise level with
the percentage of time which that level is
exceeded. For example, L10 is that level which
is exceeded \0% of the time.
Automobiles, by sheer number alone, produce the
largest source of motor vehicle noise. Tire/
roadway noise is the main contributor from autos
at high speeds. Diesel trucks are the noisiest
vehicles on the road. Figure 1 shows the
spectra of typical noise sources from trucks:
31.5 43 125 250 503 1000 2000 4000 3COO
Octave Bond Center Frequency In Hz
FIGURE 1. TYPICAL BREAKDOWN OF TRUCK NOISE
Motorcycles produce most noise from their
exhaust systems.
Predictions of traffic noise under different
roadway conditions can be made by statistical
time distribution, given vehicle volume and
average speed.
Noise can be controlled at three points: the
source, the receiver, and along the transmission
path. Limiting noise at the source can be
achieved by legislation on noise levels of
motor vehicles. Control at the receiver can be
obtained by zoning and planning of land use, and
by acoustic insulation of buildings. Reducing
noise along the transmission path can be
achieved by design of roadway configurations and
alignments. Increased distance, relocation,
and depression/elevation of the roadway will
reduce noise levels. Construction of earth
berms will also control noise considerably.
Depression of the roadway, on one case, resulted
in a 13.5 dBA noise reduction.
54
-------
01-020
EMISSIONS SUPPRESSION
Proper planning seems to be the best and most
effective criterion for control of automotive
01-020
Erskine, J. B.
Brunt, J.
Imperial Chemical Industries Ltd.,
Billingham /England/
Agricultural Division, Teeside
NOISE FROM CHEMICAL PLANT EQUIPMENT
Annals of Occupational Hygiene
Vol 14 No 2:91-99, 1971
The large scale industrial noise problem
resulting from increases in chemical plant
and equipment size together with the use of
higher fluid velocities is discussed.
One problem is compressor noise, due to blade
passage, turbulence in rotating elements of
centrifigual compressors, turbulance in by-pass
systems and normal turbulent flow in pipes.
Noise reduction has been accomplished by
removing diffuser vanes, reducing the surface
area, fitting silencers, and cladding pipes.
A second problem, fan noise, comes mostly from
air coolers, and has caused complaints from the
community. A reduction of 6 dBA was achieved at
one plant by using both inertia and absorption
silencers.
Efforts to silence the third problem, flarestacks
have been disappointing so far. Noise is a
function of the steam rate per nozzle, not the
overall steam rate. Evenness of combustion is
a negligible factor in noisiness. Use of
peripheral steam jets of different orientation
resulted in a 7-9 dBA improvement; however,
this is inadequate. New methods of flaring gas
need to be developed.
Two components of noise from vents are noise
from pressure let down and atmosphere mixing.
The sizing of pipes and vent silencers must be
applied according to location, and hence there
are no simple design rules.
For the most effective noise control, it is
suggested that possible noise sources be treated
at the design stage.
01-021
GREAT POSSIBILITIES IN NOISE ABATEMENT
Nagy lehetosegek a zaj csokkentesere
Ujitok Lapja (Budapest)
Vol 23 No 20:13-14, 1971
The SILKA sound damper, based on a patent
granted to physicist Domokos Horvath and
mechanical engineer Gyorgy Sardi, went
into series production at the Somogy County
Enterprise in Kaposvar, Hungary. The
patent, granted in 1970 and entitled
"Sound damping enclosure for damping noise
caused by flowing gases, for example,
motor exhaust gases," is an enclosure
bounded by walls consisting of multilayered
film with dead space between the layers
which are filled with loose granular,
porous or other vibration damping media.
The invention has been in use in the
Ganz-MAVAG Engine Testing Station since
1966. Noise has been abated in the plant
environment, and an attenuation of low
frequency noise of 30 dB at 12 Hz has
been attained. Previously, the noise
level in the plant environment had reached
NC 105, extending into distant communities.
The level is presently below NC 70 (about
75 dBA).
Prototypes of the noise damper will be tested
in apartment house ventilation systems in
Obuda and Zuglo. Tests on prototypes of the
MONO apartment house ventilation systems
produced by the Ventilator Plant and equipped
with the noise attenuation device show
attenuation of 15 dB. A 30-40 dB attenuation
from 110 dB to approximately NC 65 was also
achieved in exhaust noise from the compressor
room of the Pecs Leather Plant.
The noise damping device is to be applied to
damping noise from diesel and Otto engines in
engine testing stations, ventilator noise
from exhaust and air conditioning systems
in apartment houses, air filtering systems,
and noise from gas turbine exhaust systems.
55
-------
01-022
EMISSIONS SUPPRESSION
01-022
Myakshin, V. N.
Scientific Research Institute of Building
Construction, Kiev /USSR/
REDUCTION OF NOISE FROM COMPRESSOR INSTALLATIONS
Snizheniye Shuma Kompressornykh Stantsiy
Tekhnologiya i Organizatsiya Proizvodstva (Kiev)
No 1:87-88, 1971
Further reduction in noise emissions to nearby
housing can be achieved by locating the
compressor installation away from housing
areas, by orienting the intake and exhaust
pipes away from these areas, and by using
factory buildings for screening.
Effective noise reduction by means of a simple
pipe muffler was achieved for a piston-type
air compressor installation located in a
separate shed on factory property, enabling
the compressor installation to meet the Soviet
norms for noise emitted to adjacent
residential areas. Piston compressor noise
is composed of airborne noise from the air
intake and exhaust, and noise radiated from
the body of the compressor itself. The noise
spectra of four Soviet compressor installations
would not meet the legal limits within certain
di stances.
Since noise radiated from the compressor body
is mostly contained inside the shed, it is the
intake and exhaust noise of the engine that
accounts for most of the noise heard a1 a
distance from the installation. Measured at
the pipes, it reached 102-104 dBA.
A simple cylindrical muffler attached to the
air intake pipe proved effective for reducing
noise for compressors of capacity of up to
50 cubic meters per minute (Figure 1).
This muffler is simple to make, durable, and
is effective over a wide range of frequencies.
By using this muffler, a Soviet IVV-10/8
compressor (capacity 10 cubic meters per
minute at eight atmospheres) was quieted by
13-15 dB over a wide frequency range.
///r
Figure 1. Cylindrical muffler for exhaust pipe.
1. Outside surface of muffler.
2. Sound absorbing material (density 15 kG/m3,
layer thickness 100mm).
3. Layer of fiberglass 0.1mm thick.
4. Perforations 5mm in diameter in inner wall
of muffler, spaced 10mm apart. Length of
muffler: 1 meter.
5. Air intake pipe with flange.
01-023
Hi rabayash i, T.
H. L. Blachford, Inc., Troy, Ml
NOISE AND THE SNOWMOBILE
In: Crocker, M., Proceedings of the Purdue
Noise Control Conference, JUL 14-16, 1971
Lafayette, Purdue Univ., 1972, 594 p.
(p. 77-79)
The noise problem of the snowmobile is
discussed with special emphasis on methods
of measurement and control. Snowmobiles
have found wide use both for recreation and
utility. Conservationists are concerned about
th i s no i se impact on wildlife. In response
legislatures are acting on noise limits.
Snowmobile noise can cause permanent hearing
loss and has been responsible for many accidents
because of its masking effect, making warning
signaIs i naud ible.
To measure the sound pressure levels, the
snowmobile was tested in a large semi-anechoic
room with the machine blocked up so as to
allow the drive track to run free. Recordings
were taken at five positions around the machine.
The levels of a new machine were 98-101 dBA.
The following modifications were most effective:
1. All unnecessary openings in the body were
sealed. Openings which were required for
engine cooling were retained.
2. One inch of polyurethane acoustical foam
was stuck to the interior surface of the
engi ne cow Ii ng.
3. Three-quarter inch embossed polyurethane
acoustical foam was stuck to the interior
surface of the instrument console.
4. A silencer was attached to the carburetor
intake.
5.
The foot-well openings in the engine cowling
were reduced to a minimum practical size.
56
-------
01-024
EMISSIONS SUPPRESSION
These modifications did not lower the noise
level around the machine, but the value at the
operator's ear was lowered by 5 dBA. In
order to lower sound pressure levels around
the machine an effective engine exhaust muffler
must be added.
01-024
Faulkner, L. L.
Ohio State Univ., Columbus, OH
Dept. of Mechanical Engineering
NOISE CHARACTER OF A RIDING LAWN MOWER
Columbus, OH, Ohio State Univ., 12p, 1971
Minor modifications to an 8 HP riding lawn
mower enabled it to meet the ANSI Standard
B71.1 recommendations for maximum noise levels
at the operator's ear; the limit in this
standard, which became effective JUN 1, 1971,
was 95 dBA. Various noise levels measured
at the ear level microphone position were as
follows:
Configuration of Mower Sound Level (dBA)
No Muffler
Stock muffler
Stock muffler with
engine cover
Experimental muffler
with engi ne cover
98
93
87
85
Another useful method was reduction of maximum
engine speed. However, meeting community noise
ordinance limits such as those in the Chicago
Code will become quite difficult as the limits
become more stringent with time. Engine noise
may be reduced, revealing an even tougher
problem—blade noise. The Chicago Code gives
a maximum limit of 74 dBA at 50 ft effective
JAN 1, 1972, and this limit drops to 65 dBA by
JAN, 1978.
The two riding mowers tested had 4 cycle,
aircooled, non-dynamicaIly balanced engines
producing 3600 maximum RPM. Vibrating loose
parts such as the seat and fenders were
significant noise sources. A 3 dBA reduction
was obtained merely by placing a hand on a
vibrating fender. It'is recommended fenders
be removed during these tests, and that
manufacturers eliminate them. A dynamically
balanced 8 HP engine was 4 dB quieter at
ear level than the standard mower engine.
This engine would cost $12, or $3/dB more
than the standard one.
Replacement of the stock "tin can" muffler
with an experimental muItichambered muffler
reduced noise only 2 dBA, but perceived
reduction of loudness was greater because the
new muffler eliminated harsh-sounding components
at the firing frequency. Improved mufflers
alone are not the answer because direct
radiation from the engine casting was the
controlling source, not the exhaust noise.
Tests with a long tailpipe completely
eliminating exhaust noise confirmed this.
Likewise, vibration isolation of the engine
from the frame had no effect because the engine
casing itself was the controlling source. A
partial sheet metal cover with absorption
material on the engine side gave a 6 dBA
reduction, however. The absorption material
was glassfiber blanket approximately 2 in
thick.
The combined reductions achieved by the above
means are enough to meet the limit of 74 dBA
at 50 ft, but meeting the future limits of
70 dBA (1975) and 65 dBA (1978) will be a
reaI challenge.
The only other possible means of reduction,
other than drastic engine and blade redesign,
is reduction of engine speed. For these two
mowers, with stock equipment, a relationship
of about 1 dBA/200 RPM was observed:
Engine speed
3380 RPM
3175
2875
2550
2400
Sound level at ear
of operator (dBA)
92
91 .5
89.5
88
87
Reducing engine speed will perhaps be the most
common way to meet legal limits, since it
requires only the change of the governor
setti ng.
01-025
Caccavari, C.
Chicago Department of Environmental Control, IL
Engineering Div., Dept. of Environmental
Control, 320 N. Clark St., Chicago, Zip 60610
NOISE STUDY OF AN AIR PILE DRIVER
Chicago, Dept. of Environmental Control, 1971,
9p.
The problem of noise from the use of pile
drivers on steel sheet piles at a downtown
construction site was studied and a three-sided
enclosure developed that produced some quieting.
57
-------
01-026
EMISSIONS SUPPRESSION
The study, performed by the City of Chicago's
Department of Environmental Control, was done
on pile driving operations at the First National
Bank construction site. The equipment was a
double action air pile driver. Preliminary
measurements established the duration of the
peak noise, the frequency characteristics of
the noise, the repetition rate, and the true
peak level (about 122 dB at 25 feet, equivalent
to 102 RMS dBA and 106 RMS dBC).
The City recommended that a three-sided
enclosure be installed on the existing support
frames of the pile driver. The enclosure was
left open in the front to provide visual freedon
for the crane operator, but it still partially
shielded observers to the rear of the pile
driving operation. The enclosure was
constructed of an outer steel shell (i inch
sheet steel), coated with a damping compound
to minimize the vibration of the shell (i inch
"Vibradamp") and lined with U inches of open
celled polyurethane, an acoustical absorption
material.
A test was made where measurements were taken
as the enclosure was elevated above the pile
driver and gradually lowered over it. The
results showed a 15 dB reduction of the peak
level (and a reduction of 7 dBA in the "A-
weighted" level) to the rear of the pile
driver, and a slight reduction to the side of
the pile driver. (See Table.)
Sound level
Without
enclosure
With
enclosure
At rear of enclosure (about 25 ft.):
Peak levels (dB) 123 108
RMS Peak (dBA) 106 99
RMS Peak (dBC) 108 104
At site of enclosure (about 25 ft.):
Peak level (dB) 113 110
RMS Peak (dBA) 107 103
RMS Peak (dBC) 108 105
Noise levels at the First National
Bank site.
Further reductions could be achieved by
improving the design of the enclosure, which
in this case did not extend far enough down
and forward because of the presence of an
angle iron support frame. The enclosure
could be slotted to allow it to descend upon
the sheet pilings, thus better cutting off
noise emissions. By making the enclosure
more triangular in shape and eliminating the
opening on the fourth or open side through
the use of a plexiglass or glass shield, the
size of openings in the enclosure could be
further reduced. Finally, thicker acoustical
treatment would provide increased attenuation
at the lower frequencies.
In this case, the study was initiated from a
series of complaints received by the Department
of Environmental Control. A series of meetings
with representatives of the bank and the
construction company led to the decision to try
the enclosure. Additional actions agreed upon
were that air mufflers or baffles were to be
installed on all pile driver units, and a
vibro driver was to be used for extracting the
sheet metal piles after the completion of the
project.
The vibro driver is a different type of pile
driver that operates at speeds of 18 to 30
cycles per second. The vibro driver's noise
level, as measured at a second construction
site, was between 82 and 84 dBA at 20 feet,
markedly quieter than the air pile driver. This
device functions well as a driver only in
certain types of soils. However, it is
effective for the extraction of sheet metal
piling in all types of soils.
01-026
Weber, 6.
Technische Universitaet, Hannover
/West Germany/
SONIC BOOM EFFECTS 11.1: STRUCTURES AND TERRAIN
Journal of Sound and Vibration
Vol 20 No 4:505-509, 1972
Effects on structures due to pressure waves
from explosions and guns have been known and
studied for a long time. Three general sets
of parameters determine the effect of sonic
booms on the structures and terrain; (i) the
generation; (ii) the propagation of shock
waves; (iii) the characteristics of the
structures.
When an acoustic shock wave strikes the ground,
a ground wave is set in motion and travels at
a speed which is a function of the terrain
and its composition. A component of this
ground motion travels along the surface
(Rayleigh wave), exposing buildings and other
structures on the ground. Its effect on
structures would no be sufficient to cause
damage. It has been shown that ground motions
associated with sonic booms are usually of
the same order as those associated with the
passage of vehicles. The structural vibration
induced by ground motion is far less than
excitation by the acoustic shock wave.
The effect of the ground motion on surface
topographical features is the same as that
already discussed for structures. The effect
on underground features such as mines has not
been studied, but should be noted that the
amplitude of the ground motion caused by the
sonic boom usually diminishes with depth.
58
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01-027
EMISSIONS SUPPRESSION
The main effect of the boom on topographical
features, or on structures, will come from
the direct excitation by the acoustic shock
wave. On many features, for example cliffs,
existing natural disturbances such as wind
have been found to be compatible with or
greater than sonic boom disturbance. A
sonic boom could trigger a fall, but this
would only be slightly premature to the
naturally occurring event. Damage to primary
structure of dwellings even under extreme
assumptions is not be expected. Structural
elements with large surfaces and small masses
and not preloaded by other structural elements,
are more susceptible to booms than any other
structural part. Therefore damage to plaster,
panes, suspended ceilings and roofs can be
expected to be more numerous than other
structural damages. Damage expectancy will
decrease with overpressure, but theoretically
there is no overpressure level at which damage
is impossible. Relevant boom characteristics
on a certain structural part are normally not
known mainly because the free field waveform
is altered by the structure itself and by
reflections from neighboring buildings.
been successful. The best way to prevent
damage from sonic booms is to keep buildings
in a good state of preservation.
Suitable sonic boom generators can be used to
obtain fatigue data on building elements or
sections. Since there is some evidence that
higher order modes can play an important part
in the damage mechanism, it seem prudent
that experimental generators produce N-waves
that contain all frequencies found in a real
sonic boom. Three items appear pertinent for
general research. The first is glass, which
features extensively in sonic boom claims
in walls where the point of interest is fatigue
work. Third, crack propagation in plaster and
other structural elements is important.
Data on structures should be standardized to
facilitate comparison among different
experiments.
In an Oklahoma City study with 1235 sonic booms
having an average maximum intensity of about
70 N/sq.m. there was no evidence of cumulative
damage in the four test structures intensively
studies throughout the program. By a suitable
choice of buildings and by an examination of
their maintenance histories, it is feasible
that appropriate fatigue data could be
accumulated on the problem of repeated sonic
booms.
Effects of booms on structures vary from
slight vibrations, detectable only by
special equipment, to severe vibrations which
might cause damage. Type and number of
damages in structures follow a certain order.
This is determined by the peak overpressure,
the time history of the boom shock waves
and the susceptibility of the structural
element. Glass panes and plaster are more
susceptible than roofs which in turn are
more susceptible than walls. In connection
with an exposure to a sonic boom of very high
intensity in MAY 1970 over the German town of
Westerburg and some villages situated 1 km to
the south, 378 damage claims were filed. Most
involved damage to glass panes and slated
roofs where slates were shaken up. Some
chimneys were damaged, some closed doors went
off the hinges and door panels were broken.
No serious damage on the main house structures
was recorded. Extended criteria for statistical
assessment need to be developed. These can
be based on both figures of damage claims and
results from experimental investigations. In
the case of one single boom with the intensity
of 125 N/sq.m. which exposes an urban community
with a population of 500,000 people and 20
window panes/person, one window (out of ten
million) can be expected to be broken.
In several cases, preventive measures chiefly
performed to protect plaster and glass have
01-027
Wi1 Iiams, T. E.
Southampton Univ. /England/
Dept, of Civil Engineering, University of
Southampton, Highfield, Southampton S09 5NH
HIGHWAY ENGINEERING AND THE INFLUENCE OF
GEOMETRIC DESIGN CHARACTERISTICS ON NOISE
Journal of Sound & Vibration
Vol 15 No 1:17-22, 1971
In contrast to the quantitative approaches to
traffic and design problems which are available,
in highway engineering, noise is an area in
which the boundaries between quantitative and
qualitative assessments are frequently diffuse.
The motorway requires the segregation of
vehicles from pedestrians; this allows its
design as a ground level facility, an elevated
structure, depressed in a cutting or in a
tunnel. It is feasible to submerge most urban
motorways in tunnels, but the cost is so much
greater than elevated or ground level
construction that tunnels are kept to a minimum.
Thus, what would be desirable in terms of
reduction of noise is usually unacceptable on
grounds of cost, and disruption of services.
The general effect of an elevated motorway
or one which is in a cutting is a reduced level
of noise in its vicinity, although the
introduction of ramps and slip roads on
gradients result in concentrations of
relatively higher levels of noise in their
particular localities.
59
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02-001
PHYSIOLOGICAL
The results of a comprehensive factual survey
of 600 properties and 200 sites in various
parts of the United States on the effects of
landscape treatment, highway alignment and
traffic noise on property indicated the
following: (1) The depressed or subsurface
highway is potentially the greatest single
reducer of noise level. (2) Tree plantings
affect noise levels only slightly. (3) In
tall apartment buildings which are adjacent
to roads of the motorway type, the occupants
found the disturbance from traffic noise
highly objectionable. (4) Trucks were
considered the most objectionable source of
noise, insofar as it disturbed normal domestic
activities. (5) The presence of limited-access
highways of the motorway type did not result
in the general devaluation of houses and
properties which were adjacent to them. (6)
A general equation was computed by multiple
regression in indicate the probable combined
effects of distance, alignment and vegetation
of the level of noise from road traffic.
For different types of road surfaces, the
following equations were established for
passenger cars:
Open textured asphalt:
Motorway concrete:
New asphalt:
noise level (dBA)=
28+30 log (speed).
noise level (dBA)=
23+30 log (speed).
noise level (dBA)=
18+30 log (speed).
It is noted that the most effective resistance
to skidding is generally obtained from new
concrete and new asphalt. A high quality
surface is therefore beneficial both in terms
of safety and noise. The methods of shielding
from traffic noise the occupants of properties
adjacent to major highways require attention
to landscape treatment and the insulation of
buiIdings.
The importance of research in the field of
barrier design has increased because of the
problems which arise in regard to the planning
and implementation of urban projects.
02-001
Karlsson, C. G.
Royal Caroline Inst., Stockholm /Sweden/
MAN AND NOISE STRESS AND RISK OF INJURY
In: Jansson, P. G. , Conferences in Connection
with the International Air Pollution Control
and Noise Abatement Exhibition, SEPT 1-6, 1971
Joenkoeping, Sweden, 1971, 525 p. (p. 4:1-4:6)
An estimate shows that more than half the
machines in heavy industry can cause noise with
levels above 90 dBA, and that roughly 50$ of
industrial workplaces have noise levels of over
85 dBA. Since noise is known to produce
harmful effects in man, a study was made on
the physiological and psychological effects
of noise on 20 female card punch operators.
Group 1 was exposed to sound levels of 76, 82,
88, & 94 dBC on 4 consecutive working days
respectively while engaged in their normal work.
The other group was exposed to the same sound
levels in reverse sequence whi le working.
The normal sound level of the card puching
machines was 76 dBC. The other levels were
produced by playing tape recordings of punching
noise and superimposing this on the 76 dBC
level. Preliminary findings show that only
slight increases in physiological and mental
stress were observed. No proportionality was
established between the sound level in dBC and
the mental and physical reactions recorded.
These sound levels, physically speaking quite
high, produced only mild stress reactions. The
reason for this is believed to be a favorable
attitude toward the test and hence toward the
noise. However, a positive relation was
confined between subjective disturbance, and
secretion of adrenalin and noradrenaI in.
Considerable individual differences were
exhibited in reactions to the same noise
stimuI us.
02-002
Abrol , B. M.
Nath, L. M.
Sahai, A. N.
All-India Institute of Medical Sciences
New Dehli /India/
NOISE AND ACOUSTIC TRAUMA
NOISE LEVELS IN DISCOTHEQUES IN NEW DELHI
Indian Journal of Medical Research
Vol 58 No 12:1758-1763, 1970
60
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02-003
PHYSIOLOGICAL
Live music in discotheques may be more
dangerous to hearing than recorded music of
seemingly equal loudness. Discotheques in
New Delhi, India, were surveyed for potentially
dangerous noise levels, both when recorded
music (8 discotheques) and when live music
interspersed with recorded music (2
discotheques) was being played. Bruel and
Kjaer equipment was used.
In a typical discotheque the general noise
level (GNL), based on an average of 10 trials,
was 90 dB for recorded music and 109 dB for
live music from a "rock'1 band.
Frequency analysis showed that highest sound
pressure levels were found in the lower octave
bands (125, 250, and 500 Hz) for both recorded
and live music, but that levels in the higher
bands were also considerable. Sound pressure
levels in the 4000 Hz band ranged from 61-81
dB for recorded music in the various
discotheques. Levels for live music in the
same octave band were 84 and 86 dB. Background
noise was typically 20-30 dB down from recorded
music levels at all frequencies.
The authors account for the significantly
higher sound levels for live music, as opposed
to recorded music, by assuming that volume of
the recorded music was set to seem as loud as
the live music for which it was substituting.
One of the factors which contributes to the
sensation of loudness is the distortion content
of the signal, and it is likely that distortion
levels were markedly higher with recorded
music. They conclude that the levels measured
for live music definitely exceeded levels
usually accepted as ear damage risk criteria
(Lebo and Oliphant, California Medicine,Vol
107 (1967), p. 378), and that risk of acoustic
trauma existed not only for the musicians, but
also to habituees if they were particularly
susceptible to such a noise trauma.
Measurements were conducted in a weaving
plant to determine the affects of noise
on workers. Two groups were investigated:
Group I worked on a shuttle looms type
TSFS, reaching noise levels from 108 to 113 dB,
and group II operated microshuttle looms type
STB, reaching noise levels from 100 to 102 dB.
Measurements on the workers were taken 4 times
per day: before work, before and after lunch,
and at the end of the work shift.
The weavers in Group I showed more pronounced
changes in the nervous system and the systolic
arterial pressure. These changes result in
fatigue, headaches and ringing in the ears.
All of these symptoms cannot be relieved
by a noise free period during lunch or
during time away from work. Definite
measures should be taken to relieve the nervous
tension caused by noise exposure, which
can easily turn into trauma.
02-004
Becker, R.
Bonk, U.
KiessIi ng, P.
East Germany
NOISE LEVEL MEASUREMENTS DURING A FISHING
EXPEDITION
SchalIpegeImessungen Waehrend einer Fangreise
Seewi rtschaft
Vol 3 No 12:926-928, 1971
02-003
Gorshkov, S. I .
Kohan, N. A.
Kolesnikova, A. V.
PHYSIOLOGICAL CHANGES IN WEAVERS OPERATING
LOOMS WITH DIFFERENT NOISE INTENSITY
Fiziologicheskiye Sdvigi u Tkachey Obsluzhi-
vayushchikh Tkatskiye Stanki s Raznymi
Urovnyami Shuma
Gigiyena i Sanitariya
Vol 37 No 1:29-32, 1972
Noise measurements were conducted in East
Germany on the fishing vessel "WiI I i Bredel"
during its 100 day expedition. Noise meter
101 of the Technical Vibration and Acoustics
Plant in Dresden was employed and the noise
levels were measured on the A, B, C
weighting scale.
All possible noise sources were taken into
account and measured . The noise levels
ranged from 62 dBA in rooms located on the
first deck to 104 dBA at the main oil-diesel
machine.
Recommended norms for work places were
considerably exceeded on "WiI Ii Bredel".
Most complaints came from patients of the
hospital, which is located on the deck where
3 elevators for fish supplies are situated.
The highest noise levels come from the
conveyor-refrigeration unit and "fish flour
mi I I".
61
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02-005
PHYSIOLOGICAL
The guards at the main-machine use individual
Hermetos ear plugs produced by Prothetik
Plant Berlin or superfine hearing-
protection cotton from Lauscha/Thueringen.
The ear plugs reduce the noise level of
104 dBA by 22 dBA, and at level of 89 dBA by
9 dBA, at level of 93 dBA only by 8 dBA.
'"Cotton1 reduces the level of 89 dBA by 14 dBA
and that of 93 dBA by 15 dBA. At values
below 75 dBA the ear plugs, not only do not
reduce the level, but raise it by means of
resonance.
Of importance are the extra-aural noise
damages; a frequently observed noise symptom
is the delay of the stomach peristalsis.
Seamen often complain of digestive problems.
Also the vegetative nervous system is
affected, as well as pulse frequency and
systolic blood pressure. Medical research
shows that the vegetative system does not
aclimate itself to noise even though it
can be tolerated as a psychological
phenomenon.
was conducted for 5 or 6 days in each plant.
The noise level in the work area is 88 to
107 dB for 3.9 t or - 1.01 minutes and
alternates with pauses in the operation of the
test stand of 1.94 minutes, during which
the noise level is 68-90 dB. The noise is
generally of high frequency, but in some work
areas medium frequency dominates the noise
spectrum. Workers are affected by this noise
7 hours a day. The noise level exceeds the
limits prescribed by Health Norm 785-69 of
April 30, 1969 by 14-18 dB (see Figure 1).
FIG. 1. Noise Spectrum of Test Stands In an
Aircraft Maintenance Enterprise
A = ISO Curve 80
(1 - Test Stand No. 1; 2 - Test Stand No. 2)
02-005
Men'shov, A. A.
Zagurskaya, L. A.
Institut Gigiveny Truda i Profzabolevan iy /USSR/
Kiev, USSR
HYGIENIC EVALUATION OF INTERMITTENT NOISE IN
TESTING OF AIRCRAFT HYDRAULIC UNITS
Gigiyenicheskaya Otsenka Preryvistogo Shuma
pri Ispytanii Aviatsionnykh Gidroagregatov
Gigiyena Truda i ProfessionaI'nye
Zabolevan iya
Vol 15 No 10:9-12, 1971
Noise conditions were studied in areas for
testing hydraulic aviation units in four
aircraft maintenance plants. Noise meter type
2203 (Bruel & Kjaer) and octave spectrum
analyzer type 1613 were used in the tests.
The job requires working in a standing
position and manual visual coordination. It
also involves static nerve stress. The
dominant adverse working factor is noise.
Sources of noise include the hydraulic unit
itself, the engine and reducer of the test
stand, and the system for loading the test
stand. The intensity of the noise in the
work area depends on the type of unit being
tested and the test conditions. The noise
consists of alternating noise levels of
various intensities and spectral composition,
thus considered intermittent. Measurement
Subjects of the study were 6 male workers,
28-35 years old, and all worked on the same
test stand. All were practically healthy,
with normal hearing, and had been on the
job one to three years. Figure 2 shows the
spectrum of noise to which the workers were
subjected. The test stand consisted of a
test cubicle and a control console with a door
outside the cubicle. At the control console,
workers were subjected to a sound level of
92 dB for 3.02 minutes, then in the testing
cubicle for 0.42 minutes at a noise level of
104 dB, and then to 98 dB for 1.2 minutes at
the console wifh the aoor open. During the
pause in test stand operation, a noise level
of 88 dB from adjacent test stands for 2.66
minutes affected them.
FIG. 2. Noise Spectrum Affecting Workers Tested
A = ISO Curve 30
(1 - In Test Cubicle; 2 - At the Control
Console With Door Open; 3 - At the Control
Console With Door Closed; 4 - Noise Level
During Pause
62
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02-006
PHYSIOLOGICAL
The following physiological and psychological
measurements were recorded: selected air
audiometry at 125, 500, 4000, and 8000 Hz
and bone audiometry at 4000 Hz; critical
freguency of auditory flickering; performance
in the black-red table psychophyslological
tasks; memorizing numbers; muscle fatigue;
functional state of cardio-vascuIar system by
measuring arterial pressure and pulse rate.
Studies were conducted at the beginning of
work, after 3 hours work and after 30 minutes
rest.
Results showed that auditory sensitivity
thresholds increase no more than 10 dB,
within the limits of auditory adaptation;
critical frequency of auditory flickering
changes from 134 to 120.3 flickers per second;
indicators of muscle fatigue (V. V. Rozenblat
method) decreased from 117.4 to 92.5 per
second; pulse rate decreased from 73.6 to
68.7. Indicators did not return to original
values in 30 minutes of rest after 3 hours
work. No essential differences from base data
were observed for arterial pressure, short-
term memory, or performance in the black-red
table psychophysiological tasks. Results of
the study prove that the intermittent noise
prevailing in the testing areas is
physiologically adverse.
Smitley, E. K.
R i nteImann , W. F.
Michigan State Univ.,
East Lansing
CONTINUOUS VERSUS INTERMITTENT EXPOSURE
TO ROCK AND ROLL MUSIC
Archives of Environmental Health
Vol 22 No 4:413-420, 1971
In the past few years concern has risen over
the possible bad effects of loud rock and
roll music. A number of recent studies
were made on the effects of rock and roll.
Five types of experimental approaches were
used.
One method involves measuring the hearing
of people who have been exposed to rock and
roll music over long periods of time. A
study made using this method found that
95? of 42 rock and roll muscians did not
incur hearing losses, even though they had
been exposed to 105 dB sound pressure level
(SPL) of music for an average of 11.4 hours
a week for 2.9 years.
Another approach was a histological study of
laboratory animals that have been exposed to
music with a peak intensity of 122 dB SPL
over a 2 month period of time. Marked
sensory cell damage was found in the
cochlea.
Measuring high frequency thresholds is a
third approach to assessing the effects of
rock and roll music. Thresholds were found
for 24 high school musicians and for a 24
subject control group. Of the muscicians
15% were found to have poorer high frequency
pure-tone thresholds at one or more
frequencies than those in the control group.
A fourth approach is to attempt to predict
hearing loss on the basis of damage risk
criteria (DRC). DRC are the maximum intensity
levels and durations of noise exposure to
which individuals can safely be exposed.
Noise levels of 95 dB are considered
hazardous, while rock and roll music is
usually played from 98 to 108 dB.
Thus, a potentially hazardous situation does
exi st.
A fifth approach is to attempt to predict
hearing loss on the basis of temporary
threshold shift (TTS), or the reduction in
the auditory threshold resulting from noise
exposure provided that thresholds return
to pre-exposure levels in time.
Determinations have been made with the
recommendation that the TTS does not exceed
10 dB at 1,000 Hz and below, 15 dB at 2,000
Hz, and 20 dB at 3,000 Hz and above. On a
prediction basis, noises greater than
92 dB between 500 and 8,000 Hz for
a period of one hour wi I I produce as much
as a 40 dB TTS in the area of 4,000 Hz in
10? of the exposed ears, no measurable
shifts in another 10?, and a 30 dB TTS in
the remaining 80%.
A study done on the TTS approach found
SPL's as high as 120 dB produced by a
rock and roll band, with four spectators
sustaining up to a 35 dB TTS following a four
hour exposure. The conclusion was drawn
than rock and roll music poses a serious
threat to hearing.
One characteristic of the sound produced by
rock and roll is that it is intermittent.
The on-time is generally 3 to 5 minutes in
duration, and the off-time is usually less
than one minute. This allows at least
partial recovery from auditory fatigue.
Continuous vs. intermittent exposure to rock
and roll music, then, should result in
different TTS's for the respective exposures.
63
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02-007
PHYSIOLOGICAL
02-007
Kryter, K. D.
Stanford Research Inst., Menlo Park, CA
Sensory Sciences Research Center, Zip 94205
NON-AUDITORY EFFECTS OF ENVIRONMENTAL NOISE
American Journal of Public Health and
the Nation's Health
MAR:38-398, 1972
02-008
Downs, M. P.
Hemenway, W. G.
Doster, M. E.
Colorado Univ., Denver
Colorado University Medical Center, Denver
SENSORY OVERLOAD
Hearing & Speech News
MAY-JUN:10-11, 1969
Excessive noise, as everybody knows, can
impair and even damage the hearing apparatus.
But noise has other effects, too, and a
knowledge of these is necessary for a proper
evaluation of noise. The effects of noise
on mental and motor activity and on general
health and mental well-being are discussed.
Sudden bursts of noise cause responses in
man and organisms that may be designated as
"arousal1' and 'stress" responses. These
are instinctive, and exist for self protection
in potentially dangerous situations. However,
with continued exposure to a certain noise,
the organism will adapt and cease to show
an arousal response. Sudden noises will
also cause an eye-blink response, but
this does not cease with continued exposure.
Years of exposure to steady noise above 110
dB can cause temporary and permanent changes
in the size of the visual field, and noise
above 130 dB can cause (nystagmus and vertigo.
Continued elicitation of the arousal response
by noise can become stressful and can cause
damage to the cardiovascular, gastrointestinal
and neurological-glandular systems.
The awakening effects of the noise on sleep
are related to the effective perceived noise
level, the meaning of the noise to the person,
the age of the person, and the stage of sleep
the person is in. The hearing threshold as
a person goes from light to a deep stage can
increase as much as 70-80 dB. However, the
awakening reaction to noise that does occur
does not decrease with continued exposure.
Individual reactions to and attitudes toward
noise vary greatly. Some people can adapt
to noise and appear to be unaffected by it,
while those who cannot, suffer physiological
stress.
More laboratory studies regarding individual
sensitivity to noise are recommended. Open
field studies should also be conducted, but
with caution, because of the multiple variables
involved.
A study was made of the effects of amplified
rock and roll music on hearing. Specialists
point out that sound levels in the music (105-
122 dB) over prolonged periods exceed safety
limits set forth by the Committee on
Conservation of Hearing of the American
Academy of Ophthalmology and Otolaryngology.
They argue that loss of hearing is too
great a price for the dubious pleasures of
overloading the senses.
It has not been easy to show that ears are
damaged by continued exposure to the blare
of rock and rolI, although it has been
shown beyond doubt that the high noise
levels of gunfire produce permanent damage
to hearing. Apparently, standard audiometric
measurements do not show hearing changes in
young people exposed to electronic music.
Standard hearing tests are done in the
frequency range from 250-8,000 Hz.
Damage to the ears from noise exposure such
as rifle fire usually shows up in the area
near 4,000 Hz. No one, however, has shown
what effects noise exposure may have on
hearing in frequency ranges above 8,000 Hz.
Twenty-four musicians and eleven riflemen
were tested and compared with thirty-six
boys who neither played in bands nor
participated in rifle team activities.
These young men were given two types of
audiometric tests: (1) a high frequency
threshold test covering the range from
4,000-18,000 Hz and (2) a pure tone
screening test at 25 dB (ISO) in the
range from 500-8,000 Hz. In the rock
and roll group, hearing levels at frequencies
above 10,000 Hz are consistently worse than
in the non-exposed group by 10 dB or more.
In the rifle team group, differences of 10
dB or more occurred only at frequencies above
16,000 Hz.
This preliminary study poses many questions to
be answered by more exhaustive investigation.
For example, the audiometer us'ed (Rudmose
ARJ-4HF) was biologically calibrated on younger
high school students than the seniors who were
tested. The Means of high frequency thresholds,
even in the non-exposed, presumably ''normal'
seniors, were much poorer above the 10,000-
12,000 Hz range than would be expected. This
could mean that at the present time there is
64
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PHYSIOLOGICAL
02-009
great attrition to high frequency hearing
during the high school years, as a result of
ears being assailed by loud levels of noise.
Limiting Daily
Exposure Times
less than:
2 mi n
4 min
8 min
15 mi n
1/2 hr
hr
hr
hr
8 hr
16-24 hr
Sound Level
in dBA
115
110
105
100
95
90
85
80
75
70
02-009
Cohen, A.
Anticagl ia, J.
Jones, H. H.
Public Health Service, Cincinnati, OH
1014 Broadway, Zip 45229
''SOCIOCUSIS" — HEARING LOSS FROM NON-
OCCUPATIONAL NOISE EXPOSURE
Sound and Vibration
VoI 4 No 11:12-20, 1970
An evaluation is made of hearing loss risks
from exposures to non-occupational noise
conditions. Hearing loss risks exist in non-
occupational situations such as in using home
power equipment, in recreation, and from
public services like transportation facilities.
"Sociocusis" denotes noise-induced hearing loss
with emphasis on everyday noise and noise at
work. Even limited exposures to off-job
noises can cause temporary threshold shifts
(TTS) in hearing. However, even when such
noises are of high intensity, their usual
intermittency and the relatively small daily
total exposure time involved greatly reduce
their threat to hearing when compared to that
of noise at work, which is usually much more
conti nuous.
Noise conditi' "i '"• "ff-jon situations were
compared with quite protective noise limits
(deliberately chosen 15 dBA stricter than the
Walsh-Healey standards for industry). The
results suggest that people receiving frequent
or protracted exposures in everyday situations
are liable to some risk of hearing loss. Even
though daily exposures to everyday noises may
not be a distinct hazard to hearing, they may
increase industrial hearing loss by making it
impossible for the worker to find enough off-
job quiet to allow his ears to recover each
evening.
The off-job exposure criteria selected are
shown in the following table:
Continuous exposure of eight hours to octave
bands of noise in the 75-78 dBA range causes
no significant TTS in hearing at 4000 Hz, the
frequency most prone to noise-induced loss.
Typical sound levels and exposure times,
described below, may be compared with the
limits in the table above.
Recreational activities provide the highest
levels found in off-job settings.
Impulse noise, peak sound level in dB, can not
be compared with levels in dBA. A relevant
but not particularly protective criterion for
impulse noise exposure has been proposed by
the Committee on Hearing and Bioacoustics and
Biomechanics (CHABA) of the National Research
Council; peak sound level should not exceed
128-164 dB, depending on the pulse duration
and rise time. These limits apply to 100
impulses distributed over periods of 4
minutes to several hours on any single day.
Music fans who regularly attend rock and roll
sessions may risk exposures harmful to hearing.
Hazards to band members are even more
significant; one study showed the average
playing time of such musicians, both practice
and performance, was 11 1/2 hours per week.
Both musicians and listeners showed significant
differences in pre- and post-exposure hearing
levels (TTS) after a 3 hour session at 112 dBA.
(Figure 1). On the other hand, one study found
that only 2 of 42 rock musicians showed
distinct permanent hearing losses. It was
conjectured that the intermittent nature of
rock music, with on-time of 3 to 5 minutes and
off-times of about one minute, allows partial
recovery from the build-up of auditory fatigue.
Average dBA levels found in the cockpits of
small airplanes could be tolerated, according
to the off-job exposure criteria, for 3/4 hours
per day or 3 3/4 hours per week. Figure 2
shows the TTS resulting from a comparatively
short flight in a light plane.
Racing motorcycles are potentially hazardous
to hearing even with brief exposure times.
Hearing tests for sports hunters and a control
group of non-hunters show marked difference in
median hearing level (Figure 3). The hunter
group consisted of sportsmen who had used
65
-------
02-009 (CONT.)
PHYSIOLOGICAL
TEENAGE BAND
MEMBERS PLAYING
ROCK a ROLL MUSIC
O O PRE-EXPOSURE
• • POST-EXPOSURE
TEENAGE DANCERS EXPOSED TO
ROCK 8 ROLL MUSIC
O O PRE-EXPOSURE
• - -• POST-EXPOSURE
112 dBA - 3 HOURS
1000 2000 30OO 4000 6000
TEST FREQUENCY ( Hr>
assorted ri fles, shot-guns, and pistols, most
of whom had never worn ear protectors. The
hunters and non-hunter groups were of similar
age distribution, and the hunters had poorer
hearing, averaged across all ages.
1000 2000 300O 400O
TEST FREQUENCY (Mil
— Hearing levels for a sport pilot and passenger meas-
ured just before and l)eiu,een eight to snteen minutes after a
one-hour flight in a single-engine Cessna tLith cockpit noise
levels t drying between 89-91 dBA. Data from PUS sample
oiwCTuxfon.. Figure 2
In the home power equipment and appliances
category, chain saws produce the most intense
sound levels: 97-107 dBA. According to the
off-job criteria, daily safe time limits are
4-15 minutes, but in fact chain saws are
usually not used often enough to pose a serious
sociocusis problem.
Figure 1
Figure 3
JCWO JOOO *000 6000 BOOO ?SO 5OO 1000
FREQUENCY IN HERTZ (Hi)
1000 4000 «000 1000
Gasoline power lawnmowers (94-94 dBA) are used
perhaps twice a week for 4 months of the year
in most parts of the U.S. Off-job criteria
suggest limits of one hour per day or 5 hours
per week.
Home appliances (77-83 dBA) could be tolerated
from 1 1/2 to 5 hours per day, depending on the
sound level, and evidently do not pose hearing
risks unless there is protracted use on a daily
basi s.
Public transportation noise exposures of
passengers of typical aircraft (77-90 dBA),
subway cars (90-97 dBA), and buses (78-85) vary
in the amount of hearing loss risk because some
means of transportation are used much more
frequently than others. The worst problem may
therefore be subways, with a segment of the
subway riding public probably exceeding the
off-job criteria limit of one hour per day.
General environmental noises include those
radiating from airports and expressways,
construction sites, and industrial plants.
The intermittent nature of aircraft flyovers
(87-103 dBA) usually makes them a minimal
hearing loss threat. Construction noise levels
(82-98 dBA) are more continuous, can occur for
periods exceeding the off-job criteria, and
often, although supposedly temporary, exist for
several years. Roadway noise (62-98 dBA) could
be hazardous to hearing in areas where heavy
traffic conditions last for more than 2 to
4 hours per day.
66
-------
02-010
PHYSIOLOGICAL
02-010
Spiechowicz, S.
Instytut Naftowy, Cracow /Poland/
Cracow, ul, Lubicz 25a
EFFECTS OF NOISE ON THE PHYSICAL AND PSYCHICAL
EFFICIENCY OF WORKERS
Wplyw Halasu Na Spranosc Fizyczna I Psychiczna
Pracowni kow
Nafta
Vol 27 No 8:11-12, 1971
The Warsaw Polytechnical Institute prepared an
exhibition on the topic of noise. Various
kinds of equipment, abatement devices and
instruments were displayed.
The workshop on the Psychology of Work at
the Petroleum Institute in Cracow carried out
noise measurements at the oilwells of Pi I.
In the 'Babilon" Mine in Pi I noise levels
ranged up to 114 dB when drilling machines
were operated, one type even reached 129 dB.
The noise levels in the "New Tavern" Mine
(Nowa Kurczma) ranged up to 124 dB when the
same type of drilling machine was used.
Such high noise levels are not only hazardous
to the workers' ears, but also are harmful to
the nervous system of the workers. Noise
can cause headaches, fatigue, distraction,
loss of concentration and neurosis.
On AUG 21, 1959, the Council of Ministers
passed a norm establishing 90 dB as the
permissible noise level in work places.
Polish norms specify the following base noise
levels:
1. resi dences 25 dB
2. stai rcases 40
3. offices 30
4. hospital rooms 25
5. construction offices 50
6. precision offices 50
7. factory workshops 90
Noise is a subjective type of annoyance and
affects people differently, both physically
and psychologically. The effects may become
more obvious in one person than in another.
However, gradually noise affects everyone,
and this is especially evident in the
production output of workers. It is, therefore,
recommended that people working in noise
exceeding 85 dB should be sent for prophylactic
purposes for a rest in trie country, in order
to restore the;r psychological state of mind,
rebuild physical strength ana regenerate
the whole nervous system.
02-011
Thackray, R. I.
Civil Aeronautics Inst., Oklahoma City, OK
Box 25062, Zip 73125
SONIC BOOM EXPOSURE EFFECTS I 1.3: STARTLE
RESPONSES
Journal of Sound and Vioration
Vol 20 No 4:515-526, 1972
Somatic reactions to impulsive acoustic stimuli
will cause startle responses which consisr of
the startle reflex, the orienting response, or
a combination of the two. Because of their
similarity, they are often confused.
The startle reflex is prirr,aiily a muscular
response where the complete reaction consists
of involuntary contractions beginning with
an eyeblink ~-.nd rapia'v prog' e ~-s i 'ig to the
legs. The time ivs-t^i^ ^f f e tola! response
ranges from 0.3 seconas for a ml id response to
1.5 seconds tor an inter se '"eaction. There
is also a greaT increase in autonomic and
central nervous system activity. The eyet ' nK
response is the only reflex in The startle
response that does not habitats.
Stimuli of medium intensuv are I'l-elv tc evoke
the orientation response. T'ie most
characteristic reaction is a turning of +he
body or head toward fhe source. Suppression
of activity, increased receptor rensitiviiy,
and increased EEC activity also cccu' .
Startle response fends to ipipo'r performance,
while the orienting response merely serves to
alert. Tasks requiring precise arm-hand
coordination are generally inpaired tor only
a few seconds which suggests that the major
cause of the disruption is +he muscular reflex
response associated virh startle.
Tasks involving complex perceptual and or
cognitive processes may be impaired for long
periods. Significant impairment may persist
for up to th ' rty seconds. impulsive t>olse
produces impa i ; nenf by distracting atten : , on
from the central rask.
Acoustic stimuli t^o to i mpe i •* performance at
levels abcvt^ --.r.r- ;-,'marely 95 dB, But have
little <2ffeci 01 increase performance below
4 ", ; s level. Whether this value also corresponds
to the threshold for startle ref!e
-------
PHYSIOLOGICAL
vasoconstriction which are approximately
proportional to the increase in scund pressure
level. Startle or defensive reflexes are
accompanied by vasoconstriction in the head
region as well as in peripheral regions.
Orienting responses are accompanied by
peripheral vasoconstriction, but vasodilation
at the head. The predominant initial
heart-rate change associated with the orienting
response is deceleration, while startle appears
to evoke an initial accelerative response.
Intensity is not the only parameter in impulsive
acoustic stimuli. Rise time, as well as
overpressure, is a major determinant of
loudness. Both the behavioral and physiological
aspects of The orienting response n't I I habituate
completely with repeated stimulation—possibly
after 10-30 repetitions. Even a small change
in the characteristics or the stimulus ma/
result in a partial or complete reappearance
of the response.
Tracking performance has been investigated
following bursts of 105-117 dB white noise
presented against background noise of 45-34
dBA. Performance impairment was least wi th
the highest level of background no'se arid most
when the noise was at room level. These -esults
coiflict with other findings and underline the
need for further research: Subjects with the
greatest skill levels prior to presentation of
impulsive noise display the least Impairment.
Systematic research is needed on the patterns
of muscular, autonomic, and subjective response
to impulsive stimuli. Subjective measures
(i.e., rating scales) should not serve as
substitutes for objective indices of stai—le
at the present time, but it would be useful
to obtain the intercorrelations between
subjective and objective indices ir order to
determine +he extent to which such measures
could s'jbsti'J.'t lor objective one0- in future
research.
02-012
Karagodi na, I. L.
Soldatkins, S. A.
Vinokur, I. L.
Moskovskiy Nauchno-lssledovatel'skiy Institut
in". T. F. Fri °mana
MO..COW Sr .,• (-1' T i _- Research Inst of Hygiene
/USSR/
EFFECT OF NOISE PRODUCED BY AIRGRAFi ON THE
POPULATIONS RESIDING IN THE VICINITY OF AN
AIRPORT
VI yaniye Aviatsionnogo Shuma na Naseleniye,
Prozhivayushcheye v Rayone Raspo lozheniya
Aeroportshch
Gigiyena i Sanitariya
A study of aviation noise was conducted at 9
busy airports. Ranges for the dispersion of
noise at a fixed level for various types of
airplanes were measured, a public evaluation
was performed, physiolcgicaI testing on the
effect of noise was done, and safe noise levels
based on the researcn were established.
During plane landing, noise levels of 85 dBA
and higher were found to range from 9 to 19 km
away from the noise source. Noise ranges for
aircraft takeoff are much smaller: 0-12 km at
85 dBA and 9-25 km at 75 dBA. The distance
depended upon the type of aircraft used. The
'noise radius'1 therefore j/tends quite far for
relativeiv intense snund.
Public reaction to aircraft noise was
researched by sending questionnaires to 2,000
people in 22 urban and rural regions, all
located within a 40 km radius of an airport.
Adverse public reaction was found to be a
function of the following factors: noise
intensity, popu1at ion age group, and years
of habitation near the airports. Complaints go
up as noise level and ago increase, but
diminish as habitation near the airports grows
longer. Physiological investigations of the
population revealed that those living 1 to 6
km from airports suffered 2 to 4 times as much
otorhinolaryngological disorders as did those
living 40 km away.
Investigations ntado on the effect of aircraft
noise upon the human central nervous and
cardiovascular systems revealed significant
results for noise of 90 dBA. To study reaction
time, noises ranging from 50 to 90 dBA at a
rate comparable
per hour were ex
booths. Reactic
s i qnaIs va r i ed r
noises of 60 to
per hour, as com
exposed control
(1C overhead f I i
a difference in
An even greater
occurred when tt
was increased to
indicate that wh
dBA have a negIi
nervous system,
to 10-20 flights passing over
posed to people in isolation
>n time to visual and audio
inly slighfly1 (1-10 msec) for
80 dBA if ID and 20 "f I ights"
ipared with the si lence-
group. Noise levels of 90 dBA
ghts per hour), however, caused
reaction time of 19-29 msec.
difference of 30-36 msec
e number of noises at 90 dBA
> 20 per hour. These results
i le noise levels of 60 to 80
gible effect on +he central
90 dBA affects it adversely.
Effects of noise on the cardiovascular system
were also studied. Plethysmograms did not
indicate much change due to noise levels, but
pulse rater, decreased by 231? at 90 dBA.
The results of this study indicate that the
restrictions put on noise levels in other
countries are not low enough. Their standards
set aviation noise at a maximum of 100 dBA
during the day end 90 dBA at night. The
authors recommend a tightening of restrictions
to £5 dBA in the daytime and 75 dBA at night.
68
-------
02-013
PHYSIOLOGICAL
02-013
Laudanski, A.
Chotecki, B.
Sulkowski, W.
Szpital im. Pirogowa, Lodz 2 /Poland/
Oddzial Laryngologiczny
u I . Wschodnia 61 m.5
On: EFFECTS OF FACTORY NOISE ON THE EQUILIBRIUM
Wplyw halasu fabrycznego na narzad rownowagi
In: Malecki, J., Bardadin, T.,
Pamietnik XXVI I Ziazdu Otolaryngologow
Polskich W Katowicach 1968 g.
Warsaw, Panstwowy Zaklad Wydawnictw Lekarskich,
1970, 352p. (p. 80-83)
The Department of Laryngology of the Pirogow
Hospital in Lodz carried out investigations to
determine the effects of noise on equilibrium.
Tests were administered to 68 persons who at one
time or another had suffered from equilibrium
imbalance. Of these, 42 reacted rather intensely
to noise. For control group purposes 12
healthy individuals were tested. Brief noises
emitted from a weaving mi I I were used to
determine their effects on workers suffering
from ear ai Iments. The results show that noise
exposure caused vertigo, equilibrium imbalance
and other vegetative disorders in some of the
workers. The most common reaction observed was
equilibrium difficulty. The noise levels during
the experiments reached 95 dB.
The experiments consisted of audiometric
measurements, the Barre and Romberg statistical
tests for equilibrium, the Unterberg and
Babinski-Wei Ie kinetic tests, the Ha I I pike
caloric tests and the rotation test. The
duration of all the tests was between 10 to 20
minutes, depending on the patient's reaction.
Out of the 12 healthy individuals one showed a
strong reaction to the rotation test. However,
none suffered from equilibrium imbalance after
noise exposure.
The 68 patients suffered from some of the
following ailments: skull injury, Meniere's
disease, ear infection and deafness. The most
sensitive were those patients who had taken
streptomycin and had head injuries or Meniere's
disease. All authors concur that noise
definitely affects the inner ear and causes
i rritabi Iity.
Bystrzanowska, T.
Caputa, T.
Domanski, R.
Akademia Medycyny, Katedra Laryngologii, Warsaw
/Poland/
Marszalkowska 68/16
On: EFFECTS OF NOISE ON THE HEARING OF BLIND
WORKERS
Wplyw pracy w halasie na narzad sluchu w
niewi domych
In: Malecki, J., Bardadin, T., Pamietnik
XXVII Ziazdu Otolaryngologow Polskich w
Katowicach 1968 r.
Warsaw, Panstwowy Zaklad Wydawnictw
Lekarskich, 1970, 351p. (p. 18-21)
The Department of Laryngology of the Academy of
Medicine in Warsaw conducted a study to
determine whether noise affects blind workers
more than normal workers. The test group
consisted of 243 individuals ranging from 16 to
69 years of age; 99 of the group were women.
The biggest age group, from 20-30 years old,
contained 91 persons, the smallest group
contained 12 persons.
Reason for blindness fell into three categories:
1) congenital, 2) through illness and 3) through
acci dent.
About one third of the group had some degree of
hearing Ioss.
The first test showed that the noise level in
the work area in which the blind were employed
ranged from about 80 to 103 dBA.
The next step was to determine to what extent
the blind can to Ierate noise in their work,
when it becomes subjectively annoying and when
actua My tiring.
Fatigue was felt by 20.9% of the workers.
Age played no major role in the complaints.
However, women seemed to be more affected by
noise than men.
LaryngologicaI examinations showed that 10$ of
the workers manifested otoscopic changes such
as scars or perforated ear drums, especially
workers who had been born blind.
Below is a chart showing the percentage of the
whole group that had hearing loss, as well as
the similar percentages of various sub-groups.
69
-------
02-015
PHYSIOLOGICAL
53%
31%
X§S
;A^V
SiSsJ
55%
__,
.
U___j
.
•'/"
x%
* : -
M
•-y/.
//'//
' s/S
30%
\\\
"NvNs
15%
29%
r~
^
zr^r~.
\\
\\ Xs-
55%
^
'x
^
!:i';;
•:ii!
ii ''
' !'
fry
^'/.
////'
fa'.'
K. M.
R = Total group
K = Women
M = Men
U. W. Cti
^0 30 40 50 60 >60
Cause of Bl i ndness:
U = Accident
W = Congenital
Ch = Through sickness
20-60 = Age "~ange
02-015
Nagata, Y.
Institute of National Public Health /Japan/
On: PHYSIOLOGICAL EFFECTS FROM INTERMITTENT
NOISE BY SEX AND AGES
Kanketsusei-soon ni Tai Suru Shinshm Hanno
de no Sei to Men rei no Eikyo
Nippon Kooshu Eisei Zasshi
Vol 18 No 10:508
During the 90 minute periods, continuous
recordings of eIectrodermogram reaction (GSR)
and finger plethysmogram were taken. The total
number of leucocytes, acidoocytes, and basocytes
in venous blood were measured 30 minutes before
and immediately after the experiment.
Quantities of adrenalin, noradrenalin and
uropepsin in the urine were measured 30 minutes
before and 120 minutes after the experiment.
The results were as follows:
1) Regardless of sex and age, degree of
discomfort was higher when the noise level was
85 dBA than 70 dBA.
2) Regardless of sex and age, ranking of
discomfort from intermittent noises, classified
by the noise types, was arranged in decreasing
order: jet noise, pile-driver noise, tram
noise, and pink noise.
3) Except for electrodermogram reaction (GSR)
and change in pulse frequency, the greater
physiological effects were in females and in
younger subjects. Effects included: higher
frequency of pulse contraction in fingers,
increase in total leucocytes, decrease in
acidocytes and basocytes, and increase in
adrenalin, noradrenalin, and uropepsin in the
uri ne.
4) The GSR frequency was higher in men and older
subjects than in women and younger subjects.
5) The pulse frequency change was higher in
younger subjects.
For the firs"" time in Japan, an experimental
test on physiological effects of intermiltent
noise was carried out by sex and age with 10
men and 10 women as subjects. Five men and
five women were in their 20fs and five men and
five women were in their 40's. Men and women
carried out their normal light mental tasks
during the 90 minutes exposure to intermittent
noise in a sound absorbent room.
Tape-recordedd noise of the following types was
used in separate trials:
1) 60 seconds of jet noise once every five
mi nutes;
2) 20 seconds of noise from freight and
passenger trains crossing an iron bridge; once
every f i ve mi nutes;
3) Pile-driver noise putses every second for
7 minutes, followed by a 3 minute rest interval;
4) In contrast to above intermittent noises, the
pink-noise was played continuously in the fourth
trial.
The noise levels at the subject's ear were
adjusted to 70-85 dBA for trials 1-3 and fo
50-60 dBA for the pink noise.
02-016
Cottereau, P.
Ecole Nationale Vetermaire de Lyon /France/
2 Qua! Chaveau, 69 Lyon
SONIC BOOM EXPOSURE EFFECTS I 1.5: EFFECTS
ON ANIMALS
Journal of Sound and Vibration
Vol 20 No 4:531-534, 1972
The pressure waves produced by supersonic
aircraft cause variation of pressure on and
in the ground which are audible as the sonic
boom. The noise can influence the behaviour
of farm and wild anima Is while the variation
of pressure in itself could eventually cause
physiopathological disorders.
The evaluation of effects of sonic booms on
the hatchability of chicken eggs was studied
at White Sands F'roving Grounds. The particular
70
-------
02-017
PHYSIOLOGICAL
set of eggs exposed for the full period
received over 600 booms. It had a hatch of
84.3? (control 84.2/6). An ex+ensive hatching
failure of Dry Tortugas Sooty Terns has been
found. Two reasons as to the effects of the
booms were suggested; death of the embryos
after abondonment of the colony by the terns
in panic flight after exposure, or physical
damage to eggs not covered by a sitting bird
at the time of the boom.
Investigations on effects of sonic boom
(average 72 N/m2, maximum 265 N/m2) on farm
animal behaviour and performance were made in
1966 at Edwards Air Force Base in California.
The behavioural reactions to the sonic
booms were considered minimal. Occasional
jumping, galloping, bellowing, and random
movement were among the effects noted. The
poultry showed more response than the large
animals, especially in the early stages of
the tests. Occasional flying, running, crowding
and cowering were noted.
French Army dogs subjected to sonic booms with
high overpressure during focalization have been
studied. A minor effect on the cardiac
frequency and on the dogs' behaviour was found.
Certain dogs became frightened, fled and
sometimes became aggressive.
Mink reactions to sonic booms have received
more attention than reactions of other animal
species possibly because these animals are
known to be rather sensitive to unusual sounds.
The responses to the booms have been reported
as similar to responses to truck traffic, snow
plows, barking dogs and mine blasting noise in
the area.
Differences in boom intensities (average 72
N/m2, maximum 96 N/m2) had no effect, repeated
booming produced no signs of increased
excitability and reproduction in boomed and
non-boomed mink was normal.
Wild deer studied at Eg I in Air Force Base showed
no apparent response to high level sonic booms.
Animals in the London Zoo were observed in
1968 during a short program of sonic booms over
London. Except for a smaI I group of young
chimpanzees, which showed a tendency toward
fright, the reactions of the zoo animals were
negligible. Sonic booms of around 60 N/m2
caused a slight startle effect among herds of
reindeer, but only exceptionally were on-going
activities interrupted. As boom levels
increased up to 200 N/m2 the reactions became
more noticeable but none of the lying or resting
animals arose.
Only one sonic boom has been examined in detail.
In this case, a boom of an approximate
overpressure of 100 N/m2 gave an overpressure
of 1 N/m2 at a depth of 15 m in the sea. A
single fish did show a brief slowing of
heart-rate (bradycardia), immediately after
the arrival of the boom. However, fish
frequently respond similarly to other sound
stimuli, and in particular to sounds generated
by ships.
Studies have been conducted where the effects of
sonic booms on chick embroyos during hatching
are studied in terms of embryo death or
congenital malformation. Experiments were
carried out with increasing boom intensity
(100 N/m2, 300 ms duration; 500, 300; 1500,
300, etc.). Chick embryos in hatching which
were exposed to three sonic booms every morning
and three every evening every day (100 N/m2,
300 ms; 500, 300; 1500, 300, 3000, 300) were
not affected. Chicks from +hese eggs were
normaI.
Concerning wild animals the following statements
may be made with a degree of confidence:
(1) sonic booms of overpressures around 100 N/m2
have no direct, acute effects upon wild mammals
or birds; (2) sonic booms of extreme
overpressures (above 20,000 N/m2) may have the
potential to crack bird eggs, but the question
awaits an adequate experimental test; (3)
chronic direct effects on wild animals have not
been investigated, but no significant effects
of this kind are presently foreseen; (4) the
disturbance effects of sonic booms of
overpressures around 100 N/m2 on wild mammals
are probably insignificant, but the responses
of a much greater diversity of species should
be studied.
02-017
May, D. N.
Southampton Univ. /England/
Institute of Sound 8, Vibration Research
University of Southampton S09 5NH
STARTLE IN THE PRESENCE OF BACKGROUND NOISF
Journal of Sound & Vibration
Vol 17 No 1:77-81, 1971
Sudden, or impact, noise causes a startle
response in humans and may also cause startle
induced accidents. Noisy sonic booms are
examples of impact noise which can disrupt
the domestic and working environment, as well
as quiet environments. A question arises as
to whether background noise inhibits or
facilitates the startle response in humans
when startle noise occurs.
The arguments for inhibition of the startle
response by background noise are based on a
hypothesis of auditory and other masking. The
impact of the startle noise is theoretically
lessened in effect in the presence of steady
background noise.
The arguments for facilitation are based on
findings by Hoffman and Searle that backgrounc
noise increases startle in rats. This is
71
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03-001
PHYCHOLOGICAL & SOCIOLOGICAL
possibly true because startle is a response
to a potentially dangerous stimulus, and
could be greater in a stimulus of given
intensity the more inaudible (and difficult
to interpret) a background noise can cause
the stimulus to be.
Since an objective of the study was to begin
to assess a worker's susceptibility to sonic
boom accidents derived from involuntary limb
movements when he is ^tarMed, the indicant
of startle used was a measure of control
precision performance in the seconds immediately
foMorfing an impulse. A pursuit tracking tasK
was devised for the experiment.
The background noise used was essentially
white noise of 72 or 84 dBA; without it,
there was a general background level in the
room of 45 dBA, which in itself was cr 'ere
a Dackground level. The four startle iu I I
were noise bursts of 105, 112, 114, or 117 dB,
with a duration time of 40 IDS. Tne single
starfle stimulus was applied at the 4 minute
"iark at a point in the task cycle that was
identical for all subjects, the instant at
which the task cycle was mastered.
Startle was defined operationally as hand
acceleration measured from positive peak to
negative peak in the task cycle immediately
following the impulse minus that in the
task cycle immediately before the impulse.
The task cycle was 1.8 sec. A period of
essentially this length has been found to be
of interest in evaluating the effects of
startle on control precision tasks.
For startle, the effect of the background
levels was as follows:
TABLE 1
Background level (dBA)
1 Startle1
45
2.78
72
1.62
0.65
A significant value was obtained from the
results, indicating that background noise
does inhibit the starfle response in humans.
Conversely, the quieter the background, the
greater the startle amplitude will be.
03-001
Lorenz, W.
Martin Luther Universitaet, Halle-Wittenberg
/East Germany/
Halle-Wittenberg, Leninallee 18
East Germany
AUDIOLOGICAL INVESTIGATIONS OF THE MASKING
EFFECT OF AVIATION NOISE
Audiologische Untersuchungen Ueber den
Maskierungseffeet Durch Fluglaerm
Monatschrift fuer OhrenheiIkunde und Laryngo-
Rhinologie
Vol 103 No 110:438-44, 1969
A partial review of the literature on speech
interference level is given. The work falls
mainly into 3 categories: 1) differences in
the required amplitude of speech under varying
noise conditions (20 dB over various aircraft
noises, 40 dB under the noise of a compressor)
2) Characteristics of the masking effect itself
(for example, linear up to 90 dB, irregular
thereafter; degree of masking by low and high
frequency tones, both complex and pure).
3) the degree of masking permissible under
various communication condition (for example,
normal conversation and traffic).
Two sets of experiments were performed. In
the first the noise of 2 sports planes and
a helicopter was compared with white noise by
determining syllable Intel IigibiIigy at a noise
level of 95 dB and speech level of 90 dB.
Intelligibility with the 3 aircraft noises was
about 90% and with white noise about 66%.
In the second experiment 3 hearing protection
devices replaced the white noise. The aviation
noise was 110 dB and the speech level was 95 dB
in one test and 100 dB in the second test.
Intelligibility proved to be about the same with
and without the protection devices.
03-002
Von Gierke, H. E.
Nixon, C. W.
Aerospace Research Labs., Wright-Patferson AFB,
OH
HUMAN RESPONSE TO SONIC BOOM IN THE LABORATORY
AND THE COMMUNITY
Journal of the Acoustical Society of America
Vol 51 No 2:766-782, 1972
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PSYCHOLOGICAL & SOCIOLOGICAL
Present day estimates regarding the
acceptabiIity of sonic booms by man are
derived from various observations,
overflight programs, and experimental
field and laboratory studies conducted
both within and outside the United
States. The loudness and annoyance of
individual booms and their dependence
on the boom overpressure and pressure-time
function as well as the complex reaction
of individuals, groups, and communities
exposed to sonic booms of varied magnitude
and frequency are discussed.
The few experiments available proving that
even sonic booms of the maximum intensity
presently feasible do not produce direct
medical injury are described. Based on
the integrated body of results of recent
physiological, psychoacoustic, behavioral,
and sociological studies in various countries,
estimates of the effects and acceptability
of regular, frequent supersonic commercial
overland flight schedules are presented and
discussed in terms of aircraft noise
pollution in general, and of potential
certification of aircraft with respect to
noise and sonic boom.
Findings support the current policy that
commercial supersonic transport aircraft
will not be permitted to fly over the
United Slates unless and until the noise
factors are brought within acceptable
I imits.
03-003
Richards, E. J .
Rylander, R.
Loughborough Univ. /England/
SONIC BOOM EXPOSURE EFFECTS III: WORKSHOP
PERSPECTIVE
Journal of Sound and Vibration
Vol 20 No 4:541-544
The exposure to sonic booms is a new facet
in the environment. The most reactions in
man after exposure to the sonic boom were
identified by the workshop as startle, sleep
disturbance and annoyance. It was pointed out
that there are other stress reactions such as
increases in the excretion of stress hormones,
cardiovascular, gastrointestinal and central
nervous system responses.
The commonly used expression "startle" was
found to be poorly defined and often confused
with orienting responses. It was considered
essential to develop criteria to distinguish
between startle reflexes and orienting
responses, since their effects on performance
could be quite different. Minor effects on
performance were reported to occur at indoor
boom peak overpressures as low as 6 N/m2
but these appeared more likely to have
resulted from the orienting response rather
than the startle reflex. Momentary impairment
of performance on complex perceptual motor
tasks may occur after exposure to booms
of moderate peak overpressure, but is less
likely to have significant effects on
comparatively uncomplicated tasks such as
dri ving.
The effect of the sonic boom on sleep was
considered to be of great importance. Several
studies show that sleep is disturbed at boom
overpressures around 30 N/m2 under laboratory
con d i t i on s.
Data so far accumulated indicate the presence
of groups of high sensitivity or risk in the
population, notable elderly people or persons
with a neurotic predisposition. Concerning day
flights estimates of the number of day sleepers
in different communities were considered
essentiaI.
In the nominal peak boom overpressure
range of 60-100N/m2 the individuals might hear
fewer booms than they are exposed to. Booms may
be masked by background noise or decrease below
perceptible levels when penetrating through
structures.
The animal reactions encountered after exposure
to sonic booms seem to be limited to short
periods of alerting and orienting responses.
The workshop agreed that results from studies
on domestic or semi-domesticated animals were
relatively conclusive but additional studies
wou I d be requi red.
A general conclusion reached by the group
working on structures was that damage to primary
structures in buildings in good condition is
not to be expected. The type of damage that
occurs is mostly superficial and often connected
to already existing strains in the structure
itself. Although the damage in itself is
technically unimportant, its psychological
consequences in terms of a criterion for
annoyance reactions should not be
underestimated.
Based upon the available information on boom
effects in the different areas of concern in the
workshop the following suggestion for general
sonic boom exposure criteria for outdoor
reactions has been compiled. Special caution
should be exercised concerning the exact
classification of startle because this
reaction has shortcomings in terms of
def i n i t i on.
The conclusion was that whereas the nominal
peak overpressure would be adequate for certain
types of responses, the pressure rise time, the
dBA fast level or other technical parameters
might be more suitable for other types of
effects. In order to facilitate the comparison
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PSYCHOLOGICAL & SOCIOLOGICAL
between results from different research projects
the need for a common reference noise signature
was expressed. This could be in the form of
either a burst of white noise or some other
sound and should be included in all human
experi ments.
The nature of the vibrations of loose objects,
particularly the secondary response, and the
method by which such response creates sound from
shelves, tables, etc., should be examined.
There is some evidence that aural stimuli
supported by visual stimuli, for example,
amplified apparent movements by window
reflections can create fear and annoyance.
Concerning field studies, the opportunity
shoulc' be taken to perform studies in areas
where sonic booms occur regularly and are
experienced as part of normal daily life.
A problem deliberately avoided during the
discussions was how scientific information
concerning sonic boom effects should be
conveyed to the decision-makers in society.
The formation of representative groups with
sufficient technical expertise may provide
an alternafive to the situation in which
scientists feed information into a
bureaucracy which processes data and forms
decisions by its own unknown standards.
A concurrent sociological study masked a study
of general attitudes toward living conditions;
one of the problems here was the variety of
Italian words to express degrees of irritation.
It is noted that the results may be due either
to inadequacies in the questionnaire or
to exposure itself.
The following observations were:
1) With the exception of public places, all
sources of noise were noticed more by the
citizens of Stockholm than Ferrara; in the
case of motor vehicle noise, the rates were 92
and 63$, respectively.
2) Of those who noticed traffic noise, the
respective percentage of those who were
disturbed by it were 61 and 49.
3) Of those who felt themselves disturbed, the
percentage of those feeling greatly disturbed
were 23 and 21!?.
4) Of all respondents in Stockholm, 10% thought
their neighbors were probably disturbed by
traffic noise, in Ferrara, 59%.
It is concluded that "data obtained from
annoyance studies in one country are valid
in other countries without corrections.'1
03-004
Jonsson, E.
Kajland, A.
Paccagnella, B.
ANNOYANCE REACTIONS TO TRAFFIC NOISE IN
ITALY AND SWEDEN: A COMPARATIVE STUDY
Archives of Environmental Health
Vol 19 No 11:692-699, 1969
A comparative study was made of subjective
reactions to traffic noise in Swedish and
Italian block-style muItifamily dwellings
situated on either side of highly traveled
urban streets. Variables such as road width,
walI thickness, year of construction and
traffic composition are described.
The dBA scale was preferred to other more
sophisticated predictive methods. Measurements
inside residences were made with windows open
and closed, and a standard deviation was
calculated.
For all, but one, vehicle type and for windows
open and closed, the mean values in Italy
exceeded those in Sweden; for passenger cars
the differences were 8.0 and 5.4 dBA for
closed and open windows, respectively.
03-005
Mori , S.
Ritsumeikan Univ. /Japan/
13-84, Kihata Minamiyama, UjI City,
Kyoto
EDUCATIONAL ENVIRONMENT
Kyooiku Kankyoo
Koogai: Yosoku to Taisaku
Tokyo, Asahi Shimbunsha, 1971, 291 p.
(p. 145-164)
The Japanese Ministry of Education made a
nationwide survey of educational environments
in public elementary and middle schools. The
survey covered 8,236 schools (23.3? of total
schools in Japan). Many had noise, air
pollution and traffic safety problems. The
sources of noise are, principally, automobiles,
but also jets, trains in the cities, and
factories. This survey was based on the
teacher's view of the educational environment
in the 2,210 schools affected by noise.
The survey of students' opinions of the
educational environment included 108,000
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PSYCHOLOGICAL & SOCIOLOGICAL
7th grade students in 623 schools in 13
major cities. About 30? answered that
the environment in their school vicinities
was 'bad" or 'very bad." Noise was particularly
mentioned, with street noise as the worst
source of pollution.
The Osaka Educational Research Institute
measured actual noise levels in "noisy"
classrooms (Group A) and 102 "quiet"
classrooms (Group B) in 67 schools
in Osaka. Mean values of noise levels for
Group A was in the 58.8-60 dBA range with
windows open and in the 54.6-56.8 dBA range
with windows closed. This means that 80% of
the "noisy" classrooms exceeded the
environmental standard (55 dBA) designated
by the Ministry of Education.
School children in the 5th and 6th grades in
40 classrooms were questioned on noise, with
1,148 from 'noisy" and 1,552 from "quiet" rooms.
Noise bothered 50? of them. Only 6.3? said
noise dtd not bother them.
The questionnaire responses showed the following
problems in the students:
Emotional irritation:
(1) can not listen to teachers calmly;
(2) become irritated or angry;
Motivation:
(1) wish that the class period were over soon;
(2) do not want to study any more;
(3) feel like shouting;
Disturbance of mental work:
(1) often make mistakes in mathematics
problems;
(2) spend more time on solving problems;
(3) can not remember once memorized Japanese
characters (or difficult to remember);
(4) while answering teacher's question,
forget the last half of answer and therefore
can not give a complete answer;
(5) can not complete thoughts in composition
class;
(6) find it difficult to grasp contents in
reading;
Speech interference:
(1) misunderstand what teachers are saying;
(2) can not hear classmate's answer to a
question from the teacher;
(3) have to shout to the teacher for him to
hear;
(4) during class period, classroom naturally
becomes noisy;
Physical influences:
(1) when concentrating on listening, become
absent minded or get headache;
(2) become fatigued early;
(3) become sleepy and distressed;
(4) experience ringing in the ears.
The Osaka results indicate a clear correlation
between noise level and speech interference.
In teaching, normal noise level of a teacher
in a normal classroom measured at a distance
of 6 meters from the teacher is 65-66
dBA. Therefore, the noise level in the
classroom should be below 60 dBA, but since
46? of the total city classrooms have noise
levels of more than 60 dBA, the teachers
must raise their voices up to the 70 dBA
level. The teachers must therefore do a great
deal of shouting, which can be both fatiguing
and emotionally upsetting.
A study by Kyoto City of 572 students in the
5th and 6th grades found a serious effect of
noise on mental performance (calculation,
memorization, creative work and understanding).
The Uchida-Krepelin census method was used in
this test. The study reveals that noise
increases mistakes and lowers the beneficial
effects of recess. Noise as a causative factor
in mistakes was 1.3 times more important
than other factors, and the higher +he noise
level, the greater the number of mistakes.
The study also revealed that when there was
excessive noise in the outdoor recess
environment, the recess was only 92? as
beneficial as a recess in a quieter setting.
There was also a trend of increasing number
of mistakes after recess. Working efficiency
at first slightly rose (this was considered
to be the result of concentration on mental
work) but decreased drastically after 25
mi nutes.
Prof. Tama of the Osaka Educational University
studies noise effects on students' mental work
in the classroom by reproducing taperecorded
automobile noise. The speaker was suspended
from the classroom ceiling, and produced a
level of 70 dBA in the room. Children in
another classroom with a noise level of 4?
dBA performed the same tasks. The results
reveal that for such complicated menial work
for children as judgement, reasoning,
composition and reproduction of numbers in
mathematics, students in the 70 dBA
classroom scored much lower than those in
the 45 dBA classroom. Only for the
reproduction of Japanese characters were
the scores for the two rooms comparable.
The Tokyo Anti-Pollution Study Committee for
Elementary and Middle Schools made a similar
study of 18,000 students in 651 schools
throughout the country and reached similar
cone I us ions.
03-006
Stephens, S. D.
Medical Research Council,
Cambridge /England/
HEARING AND PERSONALITY: A REVIEW
Journal of Sound and Vibration
Vol 20 No 3:287-298, 1972
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03-007
PSYCHOLOGICAL & SOCIOLOGICAL
Two groups of personality inventories have
been repeatedly found to influence a variety
of auditory measures. These groups may be
referred to as the introversion extroversion
group of measures and the anxiety group of
measures, respectively. The introversion
group may be regarded as containing the
various introversion-extroversion scales, and
scales of impulsiveness, receptivity, and the
strength of the nervous system, all of which
have been interrelated. The anxiety group
of measures may be regarded as comprising
the various scales of anxiety, neuroticism,
ego-strength, and failure-avoidance motivation,
all of which are again interrelated, but
show very little relationship to the
introversion group of scales.
There is some evidence to suggest that the 2
groups influence different aspects of auditory
perception, perhaps respectively related to
different parts of the auditory pathway,
although some interaction of scales within
the 2 groups and certain complex auditory
measures has been shown to occur. The
introversion group of scales has been found
to influence largely the overall level of
arousal, the variability and perhaps the
sensitivity of the detection mechanism,
and fundamental responses to noise. The
anxiety group of measures, on the other hand
appears to be related rather to the subjective
response to noise and also the the various
autonomic responses evoked by these stimuli.
The relevance of these personality measures
to psychoacousticaI testing may be regarded
as threefold. First, in the context of
endeavoring to assess aspects of community
response to various noise nuisances, it is
important to ensure that the sample of
subjects selected is representative of the
entire population to be exposed to the noise
and does not comprise just the most sensitive
or the least sensitive group of the population.
Second, in a diagnostic context in which it is
essential to have reliable measures, it is
useful to have some indication as to the
degree of reliability which can be attributed
to the results given by certain individuals
and to distinguish the individuals who might
require more sophisticated test procedures in
order to produce reliable results. The third
and final area of relevance is in more valid
determination of the effects of various
stimuli which, may produce a decrement in
performance among the introverts and an
increment among the extroverts, so resulting
in no apparent change when the mean results
for the whole population are considered.
03-007
Rice, C. G.
Southampton Univ. /England/
Inst. of Sound And Vibration Research,
S.U., Southampton S09 5NH
SONIC BOOM EXPOSURE AND EFFECTS 11.2: SLEEP
EFFECTS
Journal of Sound and Vibration Research
Vol 20 No 4:511-517, 1972
Laboratory studies and social surveys have
provided pertinent information concerning the
general problem of sonic boom induced sleep
interference. Social survey data indicate
clearly that sleep interference is an important
human response element in community reaction
following exposure to sonic booms.
Two variables associated with patterns of human
sleep which may determine whether or not
awakening to a stimulus will occur are
accumulated sleep time and sleep stages.
Awakening in response to a stimulus appears
more likely to occur with accumulated sleep
time. Awakening thresholds appear to be lower
in Stages REM and 2, than in Stages 3 and 4,
both for ordinary noise and sonic booms.
A major factor contributing towards differences
in awakening thresholds from ordinary noise
or boom exposure is age, older people being
more easily awakened. The quality of sleep
appears to depend upon temperament, health
and responsiveness to sound during sleep.
Evidence suggests that women are more easily
awakened than men.
Stimuli with little or no information content
for the sleeper are less likely to induce a
response than a stimulus having some
significance: e.g., his name. With repeated
exposures habituation to sounds occur,
particularly when sounds are regular, frequent
and not temporari ly associated with any
subsequent noxious event. Experimental data
suggest that adaptation to the laboratory
environment is still present after several
consecutive nights of exposure to sonic booms.
In the range 25-300 N/m2 (as measured outdoors)
children are relatively insensitive to simulated
sonic booms while middle-aged people awaken to
about 30? of the stimuli. Young men are
awakened by 10-30? of stimuli depending upon
the experimental conditions and techniques.
There is insufficient evidence available to
judge the effect which existing environmental
noises have on sleep patterns and health in
the population. A limited study was performed
in Sweden where a community was exposed to 7
sonic booms on irregular days during a three
month period. The reaction was evaluated by
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03-008
PSYCHOLOGICAL & SOCIOLOGICAL
using a postal questionnaire on 220 persons.
More than 20% of this random sample of the
population had heard all the booms and about
40? indicated difficulties in returning to
normal sleep.
Standardization of experimental techniques
among laboratories is necessary. Simulators
for sonic boom sleep research should ideally
take account of both the acoustic and the
vibratory responses of typical bedrooms. The
acoustic response characteristics of the indoor
boom produced by the simulator should be
specified and measured. It is recommended
that certain EEG measures of sleep stage be
obtained. Response frequencies to stimuli
occuring in these stages should be described,
and if possible, the time for returning to
sleep following an awakening by noise. It
is proposed that at least one standard noise
be used during each experiment. Presentation
of this standard stimuli could be made to
correspond to estimated flight schedules.
Personal information must be obtained for
each subject. Sleep questionnaires and
subjective tests to assess fatigue, stress,
etc., are felt to be very good indicators of
sleep disturbance.
Existing information indicates that the
behavioral and attitudinal reaction of a
community to noise may be predicted with
reasonable accuracy only by combining the
annoyance due to the noise in question with
the total human reactions to other noises
in the environment.
03-008
Aizawa, R.
Yoshikai, K.
Nagasaki Univ. /Japan/
Dept. of Public Health, Nagasaki Univ. School
of Medicine
ON THE INFLUENCE OF CITY NOISE AT MIDNIGHT ON
SLEEP
Shinya Toshi Soon No Suimin Ni Oyobosu Elkyoo
Nippon Kooshu Eisei Zasshi
Vol 17, No 8:423-426; No 9:445-448
Traffic noise from midnight to 3:00 am
in Nagasaki City was measured with equipment
conforming to JIS 28731 equipment. The
number of outdoor measuring points was 247
in residential areas, 48 in commercial areas,
8 in semi-industrial areas, 8 in industrial
areas, and 40 in heavy traffic regions; or a
total of 351 measurement locations. Duration
of measurements was two months.
The community's annoyance reactions (relating
TO sleep disturbance) were investigated at the
same time by self-checking questionnaires
for 3,493 residents in fhe vicinity of the 351
places, Mean values of noise levels were
calculated for each point after the 10*
lowest readings were thrown out. The lowest
values of these means were 59 dBA for the
industrial area, 65 dBA for semi-industria1
and commercial areas, and 50 dBA for residential
areas.
Of the residents (1,110) investigated in the
city, 32% complained of annoyance, relating
to sleep disturbance from street noise. Their
complaints included lengthened tine for falling
asleep, waking up in the middle of the night,
reduced waking time in the morning, and
drowsiness during daytime bacause of lack of
sleep the night before. Of these 1,110
residents, 686 residents in the residential
area (28% of residents in that area), 29f>
(40%) in the commercial area, and 62 (50?)
in the semi - i ndustri a I area were disturbed
in their sleep by the street noise at midnight.
The degree of the annoyance reactions was a
function of volume ut- traffic on nearby roads.
The size of roods in Japan in decrea-ing order
is: national, prefectural, municirai, and
pri vate.
Fifty percent (101 residents) of the residents
in the vicinity of the national road in the
city were annoyed by noise. So were 42? (90)
in the vicinity of a prefecfural read, 32?
(787) in the v'cinity of city streets, and
21? (132) in the vicinity of a private road.
Thirty percent of the residents in the city
suffered sleep disturbance when the median
level of the traffic noise was 40-49 dBA.
At a median level of 55-59 dBA, abou+ 50%
of the residenfs complained of sleep
di sturbance.
03-009
Lukas, J. S.
Stanford Research Inst., Menlo Park, CA
AWAKENING EFFECTS OF SIMULATED SONIC BOOM!
AND AIRCRAFf NOISE ON MEN AND WOMEN
Journal of Sound and Vibration
Vol 20 No 4:457-466, 1972
The effect of sonic booms in the light of
potential SST development on a sleeping
populace is discussed.
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03-010
PSYCHOLOGICAL & SOCIOLOGICAL
In the course of several studies, 22 male
and female subjects, ranging In age from
5-75 years, were subjected while asleep
to simulated sonic booms equivalent to
84 dBA, and to recordings of subson'C
t3t flyover noise equivalent 86 dBA near
rne subject's ear.
'esults of these studies show general
patterns according to age and sex.
Children exhibit the least awakening,
while older people tend to be awakened
most easily. Individuals vary greatly
within common age groups, with middle
aged men with high sensitivity awakening
? out 20% more frequently than old men
with low sensitivity. Subjects were most
prone to awakening during sleep stages
2 and REM. Women were found to be more
sensitive to noise than men, in addition
Jo being awakened much more early by
aircraft flyover noise than by simulated
sonic booms.
03-010
Myasni kov, V. i.
Kozerenko, 0. P.
Yakovleva, I. Ya.
Air Force Systems Command, Wright-Patterson
AFB, OH
F >reign Technology O'v.
PECULIARITIES OF HUMAN SLEEP UNDER CONDITIONS
OF CONTINUOUS PROLONGED INFLUENCE OF
BROAD-BAND NOISE OF AVERAGE INTENSITY
Springfield, VA, NTIS, AD 696500, 1969,
17p. HC: $3.00, MF: 95 cents
Studies were conducted at the Garbov Laboratory
(USSR) on the effects of broad-band noise (2000-
12,000 Hz) of 75-78 dE intensity on sleep and
the transitional state between sleep and
wakefulness. Ten healthy subjects aged 23-36
years old were exposed to the noise continuously
up to the onset of sleep (10-12 Hrs.) and then
throughout the sleep. The reason for the study
was that Soviet cosmonauts, including Nikolayev
and Tereshkova, complained that the noise of
the spaceship cabin ventilating system (76 dB,
frequency spectrum 800-2000 Hz) interfered with
their rest, although other cosmonauts were
not disturbed. Likewise, noise in Gemini-5
periodically interfered with the sleep of
American astronauts Cooper and Conrad.
Reaction of the subjects to the noise varied
during the pre-sleep period. The broad-band
noise led to the development of drowsiness
in certain suojects and fatigue (expressed as
tension, irritableness, and absence of desire
to work) in others. Latent period of motor
reaction increased, as did thresholds of
auditory sensitivity.
Six of the ten subjects fell asleep quickly
(7-25 min). Three subjects took longer than
72 min, but in only one case was this clearly
attributable to the noise exposure. Quality
of subsequent sleep was related to how
quickly a subject fell asleep. Most of those
who fell asleep rapidly had strong and deep
sleep. Those wno did not, had superficial
sleep with frequent wakenings.
A direct relationship was observed between
restoration of auditory thresholds and the
quality of the sleep period. For subjects
with good sleep, a lowering of the auditory
threshold averaging 15-35 dB was observed in
comparison to threshold before sleep, testifying
to the restora+ion of the auditory analyzer
during sleep. Subjects who had, in their
opinion, poor sieep were observed to have
increases in auditory threshold of 15-30 dB.
Conclusions are: (1) the stay of man in a noisy
setting can disturb the quality of sleep;
(2) unequal auditory adaptation to different
frequencies can make broad-band noise seem more
unpleasant to cosmonauts in flight;
(3) the degree of restoration of disturbed
functions of the auditory analyzer is directly
dependent on quality of sleep;
(4) capacity to withstand continuous noise well
should be a criterion for selection of cosmonauts;
they should be able to sleep well, and also the
auditory analyzer should have good adaptation
as well as sensitivity to tones and speech
si gnaIs.
03-011
Dobbs, M. E.
Stanford Research Inst.,
Menlo Park, CA
Zip 94025
On: BEHAVIORAL RESPONSES TO AUDITORY
STIMULATION DURING SLEEP
Journal of Sound and Vibration
Vol 20 No 4:467-476, 1972
Although much research has been concerned with
numerous aspects of sleep in man, little
experimentation has been carried out to
evaluate the long-term physiological and
behavioral effects of sleep disruption that
might occur in response to auditory stimuli.
78
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PSYCHOLOGICAL & SOCIOLOGICAL
03-012
It is generally agreed that sleep consists of
five relatively well-defined stages during
which people respond differently to varying
levels of auditory stimulation. During a
normal night of sleep the cycle of five stages
repeats approximately every 90 to 120 min, with
decreasing amounts of stages 3 and 4 and
increasing amounts of rapid eye movement (REM)
time as the night progresses.
The auditory awakening threshold (AAT) is
defined as a measure of how much sound
stimulation is required to awaken the sleeping
human subject. Several variables are
associated with the AAT. Among these are
stimulus intensity, sleep stage, subject
differences, accumulated sleep time (and/or
time of night), amount of prior sleep
deprivation, and the amount of past
experience with the test stimuli .
It appears that the awakening thresholds in
stage REM and stage 2 are similar if the
auditory stimuli are ''meaningful' . A person in
some stages of sleep can discriminate among
auditory stimuli in terms of their personal
significance and can "listen" for certain sounds
while asleep and at the same time ignore others.
There may be some habituation to successive
stimuli. Studies have shown adaptation of a
behavioral awakening response when simulated
sonic booms and jet aircraft noise were
presented over several test nights.
Both the physiological and the psychological
consequences of sleep-disturbing auditory
stimuli are greater for old and middle aged
persons than for those of college age. The
cyclic patterns, which are clearly defined in
younger subjects, become interrupted in the
older subjects, with less of stages 3 and 4
and increasing amounts of stages 1 and 2. A
longer period for adaptation to laboratory
conditions is required for the aged than for
young adults. With increasing age, REM time
is reduced.
In this experiment it was found that the sleep
of children is essentially unaffected by either
simulated sonic booms or subsonic jet flyover
noises over intensities from 0.63 to 5.0lb/sq
ft (30.18-129.50 N/sq m) for booms and 101
to 119 PNdB for flyover noises. Partial sleep
deprivation experiments have shown that short-
and long-term sleepers have equal percentages
of REM sleep. It appears that REM sleep
duration adjusts to length of sleep.
Older age groups show greater performance
decrement with increased sleep disruption than
do younger age groups.
03-012
Scott, W. N.
Chrysler Corp. , Highland Park, IL
12800 Oakland Ave.
VEHICULAR NOISE
At: American Association for the Advancement
of Science, 138th Meeting, Philadelphia,
DEC 29, 1971
Highland Park, IL, Chrysler, 1971, 5p.
The Automobile Manufacturer's Association
sponsored a research project concerning the
annoyance due to motor vehicles. The heart
of the research project was a social survey
in Boston, Detroit and Los Angeles and
physical measurements of community noise.
The interviewees who cited annoyance with
vehicle noise were usually at home; they
were annoyed predominantly in the evening or
during the night, and 22% of the respondents
were annoyed because of sleep interference.
People were mostly annoyed by automobiles,
then motorcycles, diesel trucks and buses.
Another part of the research project related
to the subjective responses with measured noise
levels in the areas where the respondents
lived. Only a third of the variance in
annoyance could be accounted for by the
loudness level. Factors other than the
amplitude of the noise were important. It
was also shown that the peak noise levels
correlated well with the respondents judgements
of noisiness. Squealing tires, drag racing,
bad mufflers or other operator control led
action were considered the most annoying noise
sources.
It would be most efficient to reduce the peak
noise levels of diesel trucks since their
annoyance index is much larger than that of
any other vehicle. Roadway design, land
use, and traffic control may be necessary to
reduce passenger car noise. By applying
today's technology to a future truck, 1980
or later, it would be possible to reduce the
component noise levels by about 6 dB. Tire
noise will not likely decrease significantly
in the near future. Overall noise levels at
35 and 55 MPH can be expected to be reduced
to about 84 and 89 dBA respectively. At
road load, tire and aerodynamic noises are
typically equal to or greater than powerplant
generated noises. Passenger car tires already
have all the presently known tire noise
reduction techniques applied to them.
79
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03-013
PSYCHOLOGICAL & SOCIOLOGICAL
03-013
Becker, R. W.
Poza, F.
Kryter, K. D.
Stanford Research Inst., Menlo Park, CA
On: A STUDY OF SENSITIVITY TO NOISE
Springfield, VA, NTIS, AD 728332, 1971, 63 p.
HC:$3.00 MF:95 cents
The effects of certain kinds of impulse noises
and typical nonimpulse noises upon the
physiological and psychological behavior of
adults were investigated. Specific goals were:
1) to compare the effects of the two kinds of
noises, 2) to compare psychological with
physiological responses, and 3) to attempt to
find other characteristics of those individuals
who were found to have the greatest reaction to
noi se.
Sixteen everyday noises were reproduced in the
laboratory and presented to 140 subjects over a
6 month period. Typical noises included
airplanes, sonic booms, vacuum cleaners,
barking dogs, motorcycles, truck traffic, and
freeway traffic. Heart rates and
eIectromyographic measurements were made.
Subjects rated the various noises subjectively
and filled out general questionnaires on
attitudes toward noise.
The relative ranking of the perceived annoyance
of the various noises remained constant over
the six month duration of the experiment. The
2.5 psf boom was distinctly the most annoying
sound. The 1.25 psf boom was rated more
annoying than all other noises except for the
90 dBA jet flyover and the 81 dBA vacuum
cleaner. The 0.63 psf boom was rated less
annoying than all other noises except for the
67 dBA truck traffic and the 62 dBA motorcycle
recording. The sonic boom overpressures are
expressed at the levels that would be found
outside a typical frame house with windows and
doors closed; the subject actually heard the
booms and noises at the level that would be
present inside the house.
The index of psychological sensitivity to
noise revealed potential differences between
the most sensitive third of the subject
population and the least sensitive third of the
population. The noise-sensitive individuals
rated all kinds of noises as being more
intrusive in their daily activities then the
noise-insensitive individuals. They were also
more likely to perceive themselves as being
more sensitive to noise than the average
person, and they were more likely to believe
that noise was affecting their personal health.
The noise-sensitive individuals were also more
negative in their ratings of non-noise factors
in their environment and were more likely to
have high anxiety scores than were the noise-
insensitive individuals. The best prediction
of noise sensitivity came from questions about
individual's beliefs concerning the effects of
noise upon their health and behavior intended
to ameliorate the effects of noise.
Analysis of the physiological reaction to the
noise indicated a definite heart acceleration
in response to the simulated sonic booms. This
was true even of the 0.63 psf boom, which was
not rated as very annoying. It was not
possible to find an index of individual
physiological sensitivity, nor was there
evidence of correlations between psychological
and physiological reactions to noise. The
results cannot be taken as proof that such
responses and correlations did not exist;
rather the discovery of good indexes of
physiological responses to non-impulsive
noises may depend upon the monitoring of more
physiological parameters and the use of more
elaborate electrophysiological recording and
signal detection techniques.
03-014
Neki pelov M. I.
Irkutskiy Meditsinskiy Institut /USSR/
TRAFFIC NOISE INTENSITY IN IRKUTSK AND ITS
HYGIENIC ASSESSMENT
Intensivnost Transporfnogo Shuma v Irkutske i
yego Gigiyenskaya Otsenka
Gigiyena i Sanitariya
No 8:29-33, 1971
In many large cities and growing communities,
noise has become a major problem. Such a problem
developed in Irkutsk, a rapidly developing
industrial city in the Soviet Union. This
study was undertaken to measure the noise
levels of various kinds of traffic, to evaluate
public opinion of noise, and to recommend
measures for noise reduction.
Special research was carried out to determine
the characteristics of noise produced by
various kinds of vehicles. Road, air, and
railroad traffic were all taken into account.
The highest urban noise levels were created by
airplanes (81-105 dBA), helicopters (73-94 dBA),
and trucks (72-103 dBA). Automobiles were
found to produce the least noise (66-75 dBA).
During the study, peripheral factors affecting
noise levels were found. The quality of
automobile engines, conditions and velocity of
traffic, street width, building height, building
location and time of day, were considered as
factors. The highest noise levels (85-95 dBA)
were measured on unpaved and cobblestone roads.
80
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03-015
PSYCHOLOGICAL & SOCIOLOGICAL
In comparison with asphalt roads, These were
4 and 9-11 dBA louder, respectively. Faulty
engine parts emit+ed 3-5 dBA rnor, rhan
well-tuned engines. The intensi!~y of noise on
narrow streets rated 2-5 dB higher than on wide
roads. The least trafiic noise was 30-32
dBA, measured in urban apartments with
windows closed between 1 and 4 am, and fhe
most 63-70 dBA, between 8 am and 8 pm.
In Irkutsk, noise caused by air traffic affects
84.3? of its area; 20.5? of the area is subject
to noise levels of 90-100 dBA and higher.
For a subjective evaluation, questionnaires were
sent out to 700 persons living within a 10 km
radius of the airport. A large majority (65?)
complained chiefly about the noise from air
traffic, which dislurbed them day and night.
Noise from other traffic sources was reported
to be less disturbing. Those who complained
of airport-related noise rated it tw i c'j as
high as these complaining chic*i/ of fiafric
noi se.
An interesting outcome of this study was that
attitudes towards traffic noise were in
direct proportion TO Tne age of the population.
The mos f indifferent age qrojp v,as uncltr 20
years of age, wifh 15-28? registering
complaints. The age group of 21-40 years of
age had a stronger feeling howards noise (56-
67?), and those older Than 61 had The strongesf
reaction (65-77?).
If uas also found that noise tolerance to air
tratiic was related \> trc length of time the
population lived near the airport. Of those
living near fhe airport for less 1hsn 3
years,. 76-35* found the r, ,\ ,e d'sturtinj,
inhabitants from 3-6 years, 65-72?, I rom 6-12
years, 54-53?, and longer Than 12 years,
41-50?. These rosulK i-jioate that tolerance
of noise does develop in rslation to the
exposure to it.
In this study, sor:« r- »ni:,endat ions on traffic
noise control were mace oonsisting mostly of
architectural planninn and admi"'strationaI
organization neasures. Jirect ..olulion
included the paving c r roads, sf icier controls
on the loudness of automotive engines, and
the isolation of heavy .jrban traffic from
domestic areas.
03-015
Borsky, P. N.
Co Iumb i a Univ.
School of Public Health and Administrative
Me d i c i n e
On: EFFECTS OF NOISE ON THE COMMUNITY
At; American Association for the Advancement
of Science, 138th Meeting, Philadelphia, PA,
DEC 29, 1971
New York, Columbia Univ., 1971, 14 p.
Noise intensity near airports and major
highways may be approaching the health hazard
exposure levels and may be Cu'.Tr; uting +o
hearing loss. Intense no'se ^s an
environment! stressor has been found to
increase a number of physiological responses,
such as cardio-vascul ar, gasfro-intestinal,
and endocrine arid central nervous system
responses. Whether these pbys,0'ogicnl
reactions p I di. e soi.e slraln 01 the > in < srr
and if continued over suf f i 01 er.i ly long periods
are precursors or causes of disease has not
been established. It is believed that the
major acute effects of intense environnental
noise are primarily psychological annoyance
responses. 1 r: terference with sfeer- and
communications as .-.o I I as nnv.a' rec '-,'• " i.^ ,rj|
vibrations are the most frequently reported
disturbances. Variations in noise exposures
generally account tor 20-25? of the variance
in hurrtcin annoyance. Attitudes, experiences
and other human variables account for as
much as two-fhiids of tiie response differences.
Combined British and American recenf surveys
of residents living near airports indicar
that about half of all persons with moderate
psychological pivJispositions or atliTudes of
fear and aircraft operator misfeasance report
serious annoyance at Composite Noise Rating
(CNR) levels of 100 or greater. At Ihe same
noise exposures, over 70? of those persons
with feelings of high fear and high misfeasance
report high annoyance, compared to only 12? of
similarly exposed peopie wiih no fear and
feel i'ia_ of no misfeasance.
81
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03-016
PSYCHOLOGICAL & SOCIOLOGICAL
03-016
Nakamura, 6.
Kyoto City Host! pa I /Japan/
13-40 Kihata Minamiyama Uji City, Kyoto
HOSPITAL ENVIRONMENT
Byooim Kankyoo
In: Kocgdi. Yosoku to Taisaku
Tokyo, Vjahi Shimbunsha, 1971,
?9!f.. (p. 164-174)
Three doctors at the Kyoto City Hospital made
a sti've/ of 956 families and 293 clinics
'providing both out-patient and short hospital
s+ay services) ana physicians' offices to find
out the effect of noise on their envircnnent.
The questionnaire covered the following areas:
(1) influence of noise from daily activities
on conversation, lelephone calls, reading and
concentration while at work; influence on
chi Idren's study;
(2) emotional irritation; influence on
recuperation at home;
(3) sluep disturbance in the middle of the
night 21 id eariy norning;
(4) disturbance of naps;
(5) physical effects: appetite, fat'gue,
headache, palpitation and ringing in the ears;
(6) influence on ability to listen to a
stethoscope.
Degree of Nuisance (DN) was calculated in
terms of percentage by dividing the number
of people answering ''yes" to the question
"is noise a nuisance?" by the total number
of respondents. The results of the survey
from residents reveals that DN/emotional
irritation was more "than 50* when the noise
level war, more than 50 dBA. This DN was 15-25?
higher than DNs tor other Types of effect.
When noise level was more than 60 dBA,
DN/emotional irritation was 69?. Adverse
effects on naps, daily activities, and sleep
were rankec second, third, and fourth
respectively, in DN in this survey.
The survey of clinics and doctors' offices
shows that DN is much higher for the same
noise level than it is in a residential
setting. When the noise level is 36-40 dBA,
DN/emotional Irritation is 36-40?. When
the level is 50 dBA, the various DNs are
much higher- 67? in doctor's conversation
with patients, doctor's rounds, and
audiometry; 80? in listening to 1 he
stethoscope; and 90? in listening to a
fetus by stethoscope. When a doctor listens
to the stethoscope during chest diagnosis and
treatment, DN is 65$ for a noise level of
30-40 dBA.
The frequency of lung and bronchial sounds
is below 1000 Hz and in the 2000-3000 Hz
range for coughing. A stethoscope on the
market today has a transmission loss of
30-40 dB in the 2000-4000 Hz range.
Vibration of the rubber tube itself and
permeability of noise through the rubber
tube from outside noise make the stethoscope
more difficult to use, particularly for city
doctors. When the background noise level
increased from 30 dBA to 35 dBA, patients
required 20? more time to fall asleep and
woke up earlier in the morning 10$ of the
time. The survey found that a mean noise
level of 50 dBA within the hospital caused
emotional tension, sleeplessness and shouting
when conversing. The main sources of noise
within the hospital were loud speakers, radios,
cooking in the kitchen, trucks, ambulances,
footsteps, elevators, motors, noise from
experimental animals, and cleaning by
Jan itors.
The survey also found that when noise level
exceeded 60 dBA, 60-69? of patients either
(1) complained by telling doctors that they
wanted to recuperate at some other place,
(2) got angry or, (3) became nervous. Also,
50$ of patients complained that they could not
sleep, and had to shout to carry on a
conversation. Doctors and staff also
complained about difficulty in using
stethescopes.
When the noise level was 55 dBA during morning
and evening hours more than 50? of both staff
and patients were annoyed. The level
prescribed by the environmental standard is
40 dBA.
The survey found that noise did not result in
doctors making many more mistakes in diagnosis.
However, the frequency of mistakes by the staff
increased in simple tasks such as matching blood
for transfusions, measuring correct quantities
of the right medicines, and recognition of
patients.
03-017
Angevine, 0. L.
Anderson and Angevine, Inc., E. Aurora, NY
PSYCHOLOGICAL FACTORS IN ACCEPTANCE OF NOISE
New York, Anderson and Angevine, 10p.
82
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03-018
PSYCHOLOGICAL & SOCIOLOGICAL
Emotional or subjective reactions to noise
vary from one individual to another. Several
psychological factors are involved which will
determine a person's attitude toward noise:
1) Noises produced by other people are more
disturbing than noises produced by oneself.
2) A certain noise must be perceptible against
background noise to become irritating. Music
and speech are more difficult to disregard than
random sounds.
3) People who suffer from anxiety are much
more likely to be disturbed by noise than those
who do not.
4) Individual conditioning and perception of
reality determines how a person will react to
noises. Individuals who were exposed to air
raids during WWII will react much differently
to sirens than will those of today's generation.
5) Adaptation to a noise develops if it
maintains a steady value; only if there are
changes in the noise itself will it then be
noticed. Also, noise is more apt to be adapted
to if it occurs in the presence of background
noise.
6) Individual interpretation and recognition
of sounds determine whether they are annoying
or not. For example, a man experiencing the
noise of an earthquake for the first time
thought his furnace had exploded.
7) A study has shown that people will accept
more noise from aircraft than from cars simply
because they accept aircraft to make more noise.
8) Reaction to noise also depends upon its
appropriateness. Consider the difference
between hearing a brass band while in church,
and hearing it while watching a parade.
9) Some noises are not annoying until they
are combined with mental pictures. The sound
of fingernail running down a blackboard does
not bother some people until it is identified.
Then, it is intolerable.
10) Cultural differences influence the loudness
of conversation. Americans are generally
considered very loud talkers by Europeans.
11) Once a person complains about noise, he
is thereafter much more sensitive to it.
12) Fatigue from noise comes from trying to
talk above it or not being able to talk
above it. Thfs fatigue can lead to stress.
13) Biological rhythms, common to both men
and women, determine response to noise. At
the time when a person is most awake, noise
wi I I have the greatest effect.
03-018
Hockey, G. R.
Durham University /England/
Dept. of Psychology
EFFECTS OF NOISE ON HUMAN EFFICIENCY AND
SOME INDIVIDUAL DIFFERENCES
Journal of Sound and Vibration
Vol 20 No 3:299-304, 1972
Laboratory research into the effects of loud
noise on the efficiency with which human beings
carry out mental work has a long history in
experimental psychology. Much recenr research
has tended to concentrate on continucjs noise,
as found in most industrial and n I'tery
situations, and particulary unchcijirg broad-
band noise. Performance changes t rought about
by exposure to continuous noise aduaily
increase with time spent at the tas One
such task is that of vigilance or monitoring.
Normally, efficiency at monitoring drops
off with time spent on the task. Noise,
in these studies, accentuated this effect,
increasing the number of signals missed, but
only at the end of the work period. Although
noise does not affect the overalI speed at
which successive decisions are made, it
does increase the number of wrong decisions
(or result in occasional very long decision
times).
It is important to point out, however, that
noise can sometimes enhance efficiency of
work. A number of studies have demonstrated
better performance at the end of a vigilance
task when the level of background noise was
continuously varying, though this is the
kind of environment which is usually associated
with distraction. Certain kinds of variable
noise (that of a car radio, for example)
clearly prevent boredom and may thus have a
real effect on efficiency.
Noise can be assumed to have a general effect
of increasing the amount of stimulation reaching
the central nervous system (CNS). On the basis
of results from clinical observations and
research on anxiety and the psychological stress
it has been suggested that a high level of
arousal may result in efficient behavior. A
principle of this kind has been found to apply
to the effects of noise in monitoring tasks.
Primary task performance (tracking) is
faci 'itated, especially towards the end of 40
minute work period, while monitoring is, on >"he
whole, impaired. Signals occuring near the
periphery of vision (80 degrees each side) are
more likely to be adversely affected by noise
than those in the center, which may show an
improvement. In other works, noise is
producing a structured change in the way in
which attention is distributed over the
83
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03-019
PSYCHOLOGICAL & SOCIOLOGICAL
components of the task, causing it to become
more selective. This has the effect of
enhancing performance on high priority aspects
of the task at the cost of neglecting low
priority elements.
Little is known of the relation between
personality and susceptibility to loud noise,
at least as far as changes in efficiency are
concerned. The Heron unsociabi I ity scale,
a measure of introversion-extroversion, has
proved to be of considerable value in accounting
for individual differences in mental work
efficiency in general.
Both tracking and selectivity give consistently
positive correlations with introversion. The
degree to which the distribution of attention
changes with noise, however, is consistently
negatively correlated with introversion.
It has been demonstrated that liking for noise
exhibited by extroverts extends to preferred
levels of continuous white noise in the same
kind of task. It is not at all clear at the
present time how these differences between
individuals in the effects of noise can be
interpreted. The underlying basis fcr such
differences will probably be found in further
neurophysiologicaI work on the structure of
the various mid-brain arousal systems and
thei r control.
The highest noise intensities occurred on the
lower floors of the buildings, and in
buildings with panel construction. Noise
intensities themselves were found to depend on
the water pressure inside hydrant fixtures:
the higher the water pressure, the higher
the noise levels.
The noise levels had more effect on confined
and sick people than others. Complaints of
noise ranged from 56-73$ of those polled;
64-89? of the inhabitants of panel
construction buildings complained of noise,
while 52-77% of those living in brick
buildings with iron reinforcements complained
of noise.
A direct relationship was found to exist
between the noise level and the number of
complaints. As the noise level increases by
5 dBA, the number of complaints increases by
10%.
It is concluded from this study that the noise
from water fixtures in apartments is a serious
problem, and that more attention should be
paid to quieting it by acoustic insulation.
03-019
Neki pelov, M. I.
Irkutsk, USSR
On: INTENSITY & DISTURBING EFFECTS OF NOISE
CREATED BY PLUMBING IN BUILDINGS
Intensivnost, i Bespokoyashcheye Deystviye
Shuma, Sozdavayemogo Vodoprovodno-
Kanalizatsionnym Oborudovaniyem v Zdaniyakh
Vodosnabzheniye i Sanitarnaya Tekhnika
No 1:13-15, 1972
Establishment of controls on construction
organizations for reducing noise is reported
in the light of an investigation of plumbing
noise in buildings conducted by the
Department of Hygiene of the Irkutsk Medical
Institute.
The test assessed the noise intensify 11 UH,
v.rier ; ., .jrJ systems in domestic quarter-1
in various regions of Irkutsk. MuIti-bfuriod,
we I I-constructed buildings, new ano Id, W'.re
evaluated. Subjective public reaction to the
noise was obtained from questionnaires
delivered to the inhabitants of 657 apartments.
A total of 2,015 noises was measured during the
course of the study.
03-020
Stanios, W.
Semczuk, B.
Domanska, K
Akademia Medyczna, Lublin /Poland/
Lubli n, Poland
HEARING DAMAGE AND RESULTS OF CLINICAL AND
PSYCHOLOGICAL RESEARCH ON PERSONS WORKING IN
NOISE
Uszkodzenie Sluchhu Oraz Wyniki Badan
Klinicznych i Psychologicznych Osob
Pracujacych w Halasie
Pamietnik XXVII Zjazdu Otolaryngologow
Polskich W Katowicach 1968 r.
Warsaw, Panstwowy Zaklad Wydawnictw
Lekarskich, 1970, p. 15-17
A study was undertaken in Poland to determine
the aural and extra-aural effects that result
from occupational noise. The group examined
consisted of 500 persons, 20 of which were
women. The examination was subdivided into
otolaryngologicaI and internal. Hearing was
tested by means of whispering. Blood pressure
was taken before and after work and an eye
test was given. Reaction tests were also
given to determine concentration span and the
quickness of perception.
84
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03-021
PSYCHOLOGICAL & SOCIOLOGICAL
Analysis of group I of the KFWM Plant working
between 2 and 4 years in noise levels of
100 dB showed 18.3? of hearing loss, and
decreased hearing sensitivity by an amount
of 25-35 dB. In workers of 5 to 10 years the
percentages rose to 19.2 and loss of
24-35 dB, and for those employed for 11 or
more years the percentage increased to 25.4?
and loss of 29-44 dB.
In a noise environment of 100 to 122 dB,
the statistics showed a 2-3? increase in each
category. Also the blood pressure increase was
from 3-5 mm Hg.
For the psychological test, 2 groups were used:
the first group consisted of 75 persons who
worked in noise surroundings up to 100 dB and
the second group involved 25 persons employed in
noise levels above 100 dB. Tests were
conducted before and after work. The reaction
time of the hearing stimulus before work in
group I was 280 msec and 303 msec after work.
In respect to visual stimulus, the reaction
time was 274 msec before work and 289 after
work.
It was found that after 3 hours' work in noise
levels 90 dB and above, the concentration span
and quickness of perception showed considerable
drop.
The study showed that a degree of hearing loss
occurs in noise levels of 85-100 dB, and that a
temporary threshold shift of up to 13-18
dB occurs after work, but is rectified to a
certain degree after a few hours rest. In the
light of hemodynamic changes and psychological
reaction, noise is definitely a negative factor.
03-021
In five workshops the following factors were
studied: type of work, source of noise,
intensity of noise, spectrographtc character
of noise, mode of exposure to noise, and the
situation and response of the worker to noise.
A questionnaire surveyed 920 workers and 8
general kinds of complaints were determined:
1) fatigue, 2) headache, 3) palpitation,
4) stiff shoulder, 5) decrease in body weight,
6) disturbance of sleep, 7) irritation, and
8) gastrointestinal disturbance.
Also surveyed were 92 workers exposed to noise
in an adjacent workshop over a 3 month period.
They were investigated before and after the
administration of a placebo.
Workshop D had the highest complaint rate, as
compared with workshop E, which had the lowest.
There was no direct relationship between all
types of complaints and actual noise level,
except in the case of workshop E. Noise
levels in workshop A were the highest, although
workshop D registered the most complaints.
These results cannot be interpreted on a
physical noise level basis alone. Another
factor other than noise intensity and hearing
damage must exist. Workshop D was the only
one which did not produce its own noise; hence,
it may be more irritating to listen to noise
from a source other than one's own.
Fig. 1 shows the results of the group
administered a placebo. In each group there
was not much change in complaints. The results
of this study indicate that complaints related
to noise exposure do not necessarily relate
to the intensity of noise. A psychological
factor must be involved. Conversely, the
results of the study on the placebo group
indicate that the basis for complaint is not
completely psychological either. A reasonable
balance must be somewhere in between.
Matsui, K.
Sakamoto, H.
Mie Prefectural Univ., Tsu, / Japan/
THE UNDERSTANDING OF COMPLAINTS IN A NOISY
WORKSHOP
Ergonom i cs
Vol 14 No 1:95-102, 1971
This article reports testing to determine
personal attitudes toward noise. Although
the Noise Rating Number developed by the
International Standards Organization (ISO)
converts a physical value into a psychological
value, individual attitudes toward noise vary
greatly, and there may be no complaints even
though noise levels are dangerously high.
The Noise Rating Number is not adequate to
determine personal attitudes toward noise.
5 6
it
a
I *
"p*
e
o
U
•8 2
I
\777\
Before Administration
After Administration
/
Occasionally entirely punctually
Moae of Administration
FIGURE L Changes in the Number of Complaints Before and
After Administration of Placebo
85
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03-022
PSYCHOLOGICAL & SOCIOLOGICAL
03-022
Burrows, A. A.
Zamarin, D. M.
Douglas Aircraft Co., Inc.
Zip 90801
AIRCRAFT NOISE AND THE COMMUNITY: SOME RECENT
SURVEY FINDINGS
Aerospace Medicine
Vol 43 No 1 :27-33, 1972
To study community reaction to aircraft noise,
two surveys were conducted in 1968 and 1969 in
the communities surrounding Los Angeles
International Airport. The survey
questionnaires sought information in the
following areas:
1. Identification and definition of aircraft
noise as a problem-comparison with other major
probI ems
2. Awareness of aircraft noise and its effects
on daily activities
3. Emotional reactions to aircraft noise
4. Noise abatement activity
5. Prior awareness of aircraft noise
6. Perceived economic effects of aircraft noise
Figure 1 shows the results of a rating of the
seriousness of 4 current problems, including
aircraft noise.
The frequency of awareness is shown in Figure
2 for the total sample and by distance to the
ai rport.
Of the sample 31? were aware of aircraft noise
twice a day or more, while 2\% were never aware.
Those respondents living less than 3 miles from
the airport were much more likely to be
continually aware of aircraft noise. Awareness
of aircraft noise changed with the time of day,
being low from 1:00 am to 1:00 pm. A gradual
increase occured between 1 and 5 pm with a
rapid increase after 5, with a peak awareness
at 7:00 pm.
Respondents were asked about their emotional
reactions to aircraft noise. Figure 3 shows
the most common responses. The majority of
the sample reported no reaction at all. The
next most frequent responses were "annoyance"
and "acceptance." It was found that people
most exposed to aircraft noise tended to
polarize in their reactions, becoming either
angered or adapted to it.
FIGURE 2.
Frequency of awareness
of aircraft noise.
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, .DISTANCE
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FIGURE 1. £
Seriousness ratings for o so
four current problems. £
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86
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03-023
PSYCHOLOGICAL & SOCIOLOGICAL
Only 4% of the sample had ever made a complaint
(6% in 1968). Complaints were generally that
there was too much noise or that aircraft were
flying too low. Most respondents felt there
was no result from their complaints.
The survey on prior awareness of aircraft noise
showed that 43? of the entire sample knew of
it before moving in, and 60% of those living
within 3 miles of the airport were aware.
The economic effects of aircraft noise were
important to most people. Respondents were
far more likely to perceive an increase in
their property value over the preceding 5
years than a decrease.
When asked how much they would be willing to
spend to eliminate aircraft noise, 58% of the
sample answered that they would be unwilling
to pay anythi ng.
Of the sample 49% were aware of current noise
abatement activities, while 66% of those
living within 2 miles of the airport knew
about them. The most frequently mentioned
activity was "developing quieter engines."
The results show that community reaction to
aircraft noise in Los Angeles is not as great
as might be expected. Annoyance is about even
with apathy, and complaints are almost
neg I i g i b I e.
^ 1 TOTAL SAMPLE IN-5001
[ ] DISTANCE FROM THE AIRPORT
A = 02 MILES (N=63I
i
-1
w
I
I — '
28
C = OVER 3 MILES iN-351)
25
14
fT
2,
16
10
rn
5 ft U
1 Flfi f¥un
15
„
9
15
^
1
^
ss
10
23
1
_
ABC ABC ABC ABC ABC ABC
AGGRAVATION US€D TO IT
Figure 3. "Usual" reactions to
aircraft noise.
03-023
Volkov, A. M.
Karagodi na, I. L.
Tsysar, A. I.
Ail-Union Scientific Research Institute of
Hygiene in Railway Transport /USSR/
THE ASSESSMENT OF RAILWAY TRAFFIC NOISE BY THE
POPULATION (QUESTIONNAIRE DATA AND VERBAL
ASSOCIATION EXPERIMENT)
Otsenka Naseleniyem Shuma Zheleznodorozhnogo
Transporta (Po Dannym Oprosa i Slovesno
Assotsiativnogo Eksperimenta)
Gigiyena i Sanitariya
No 2:29-32, 1971
Mass complaints of high noise levels from
the population living near railroad tracks
near Moscow prompted a study on public reaction
to noise and resulted in a verbal association
test. Noise had become such a nuisance and
•distraction to inhabitants that 87? of the
population filed complaints.
The neighborhood studied was broken down
into 3 areas, and noise levels in dBA recorded
for each: 1) 40-100 meters from railway lines,
with a maximum measure of 84 dBA; 2) 150-180
meters, measured at 67 dBA; and 3) 250-280
meters, measured at 63 dBA.
It was found that the most intense railway
traffic occurred between 1 and 5 am, which
resulted in sleep disturbance for the
neighboring population.
To measure subjective reaction to railway
traffic noise, questionnaires were distributed
among the inhabitants. Of the 144 persons
living in the area 40 to 100 meters from the
railroad tracks, 126 (81%) complained of
intense discomfort and disturbance; 47-64?
reported interruption of sleep because of
intense traffic in the early morning hours;
and 21-45? complained that noise from the
trains and signals caused fright in their
chi Idren.
Inhabitants living 150-200 meters away from
the noise source reported less discomfort due
to railway taffic; about 50% had serious
complaints. For those at a distance of
250-300 m the noise was even less disturbing,
though still noticeable.
For an objective analysis of the effect of
railway noise on the population, a verbal
association test was given to 136 persons
living near the noise source. Subjects were
presented with a list of general words,
interspersed with key words such as "silence,"
"train," "station," "transport," and
"sleeplessness." Reaction time to key words
averaged out to 1 second longer than reaction
87
-------
04-001
ECONOMIC ASPECTS
time to general words, in all groups tested.
This is in comparison to the control group,
which showed a 0.6 second difference in
reaction time. The group closest to the
railroad tracks showed the most delayed
response time. It was inferred from this
study that high noise levels have detrimental
effect on the central nervous system, and
cause a delay in response to verbal cues
proportionate to the noise level.
Typical responses to the key words themselves
showed the influence of railway traffic
noise upon the public. For instance, in
response to the key word "silence,"
almost 15% answered: "(it) will never be,"
"seldom," and "loudly." To the key word
"sleeplessness, responses were: "often,"
"didn't sleep," "because of the trains,"
"because of the noise."
This study shows that high noise levels can
affect a community. Even latent response time
in verbal speech is affected, indicating the
effects of noise on the central nervous
system.
Distance from
railroad tracks
(in meters)
TABLE I
Maximum noise
level with
windows open
(in dBA)
Latent verbal
response time
to words (i n
sec)
Genera I
Key
40-100
150-180
250-280
84
67
63
3.3
2.7
2.4
4.3
3.7
3.4
Control Group
2.6
3.2
meet at present. On the other hand, a too
lenient code limits maximum permissible noise
to 85 dBA at 100 feet.
In quieting machinery, some negative factors
involved are increased cost, size, or
ineffective work and difficult maintenance.
The cost of mufflers for most hand-held tools
is from zero to five percent of the cost
of the unmuffled tool. However, cost for
the development of a paving breaker with a
built-in exhaust muffler and built in force
cancellation totalled over $300,000.
Drills without noise control produce about
120 dBA at one meter, which can be reduced
to 100 dBA at a cost increase of 10-15$,
and to 90 dBA at an estimated cost increase
of 30-40?. The cost increase of reducing
compressor noise from 110 dBA to 85 dBA
(at one meter) is about 30*. For smaller,
gasoline engine driven units the cost
increase is about 10-15?.
04-002
Ostergaard, P. B.
Ostergaard Assoc., West CaI dwell, NJ
10 Glenwood Way
CAN INDUSTRIAL PLANTS BE ADEQUATELY QUIETED?
At: American Association For The Advancement
of Science, 138th Meeting, DEC 29, 1971
West Caldwell, NJ, Ostergaard Assoc., 1971,
14p.
04-001
Diehl, G. M.
IngersolI-Rand Research, Inc.,
Princeton, NJ
CONSTRUCTION EQUIPMENT-WHO WANTS IT QUIET?
At: American Association for the Advancement
of Science, 138th Meeting, Philadelphia,
DEC 29, 1971
Princeton, IngersolI-Rand, 1971, 14p.
One of the targets of noise control legislation
is construction equipment noise. Noise control
codes of various cities, however, are either
too strict or too lenient. An example of
the former is a code which prohibits paving
breakers from producing over 85 dBA at a
distance of 1 meter, an impossible standard to
Industrial noise as discussed in this report,
can be divided into two general areas of
concern. One is the high noise levels within
factories. The other is the noise which a
factory radiates to the community and which
annoys people residing near the plant.
When a factory becomes a community noise
nuisance, legal action can be brought against
it by annoyed neighbors. It is expected that
noise levels will be set by environmental
organizations such as the EPA.
Reducing the noise that radiates outside a
factory is discussed. Enclosing the plant
prevents the escape of noise to the outside;
in doing this a closed loop air system
circulation is used with the added advantage
of purifying the air.
The installation of mufflers on fans and vents
outside eliminates noise at little cost.
Distance from neighborhoods, of course, is
88
-------
ECONOMIC ASPECTS
04-003
always an important factor. The best solution
to the noise problem is the development of
quiet equipment.
The question concerning noise control is what
kind of costs are involved. It is fairly cheap
to provide an employee with ear plugs or
earmuffs. The cost might run anywhere from
$5.00 to $10.00 for plugs or muffs and this
should provide around 30 to 35 dB of noise
reduction in the critical frequencies, if the
employee wears them properly. This form of
noise control, however, may not be particularly
cheap when the noise source is one or two
machines and many, many employees are subjected
to the noise levels. These costs work out to
be 25 to 30 cents per dB per employee protected.
Noise control for the path is harder to
estimate. Barriers, for example, when installed
can be quite sizable in extent. The cost of
installation may be about 50 cents per square
foot and the noise reduction in the order of
15 to 20 dB. This means the costs will be
something Iike 3 cents per dB per square foot
of the barrier. To be effective, the barrier
may have to encompass 50 to 60 square feet
and the costs then run roughly $1.50 to $2.00
per dB.
A complete enclosure around a piece of machinery
will probably provide twice as much on a decibel
scale than a barrier, but the costs run around
ten times as much. The benefit per employee,
however, can be quite high since all employees
will benefit from the noise reduction of the
machine which has been enclosed.
The amount of noise reduction which can be
achieved using sound absorbing materials is
usually limited to something like 10 to 15 dB.
The costs will run something like 10 cents per
dB square foot of material. Since it is
essential that practically all of the interior
surface of the plant be treated with sound
absorbing materials, the cost can be quite high.
However, when it is distributed over all
employees, the cost might be quite low.
In figuring aii of the costs above, no account
has been taken of the engineering work which
may go into studying the noise source, etc.
It's obvious that in the long term it is going
to be the purchase of quiet machines in a plant
which will provide the most noise control.
The whole approach in the longer range future
can be summed up by the two words: "buy quiet".
04-003
Paik, I. K.
Urban Transportation Center,
Washington, DC
IMPACT OF TRANSPORTATION NOISE ON URBAN
RESIDENTIAL PROPERTY VALUES WITH SPECIAL
REFERENCE TO AIRCRAFT NOISE
Springfield, VA, NTIS, PB 1940101, AU6, 1970,
23 p. HC:$3.00 MF:95 cents
The purpose of this study is to establish some
statistical evidence on the effect of
transportation noise on residential property
value, especially on the value of residential
property in strictly residential areas in
comparison to that in commercial areas.
The study was made up of 2 parts: The first is
an attempt to measure the impact of variations
in the level of aircraft noise on residential
property values in the vicinity of John F.
Kennedy Airport. The second consists of a
comparative evaluation of the noise effects
between the relatively commercialized
neighborhood in the same vicinity.
The technique used was the linear regression
method. Data consisted of 162 observations
from the 1960 U.S. Census of Housing and
PopuIation.
In all models of the regression equation, the
noise level turned out to be a statistically
significant factor. The level of significance
was slightly higher for the residential area
compared to the commercial industrial area.
The sizes of houses turned out to be the most
important price determining factor.
At this point, nothing can be said on the
validity of using the result for policy purposes
until the study is completed and the predictive
capability of the model is tested.
04-004
Thomas, R. J.
W. S. Atkins & Partners, Epsom /England/
Environmental Development Group
TRAFFIC NOISE-THE PERFORMANCE AND ECONOMICS OF
NOISE REDUCING MATERIALS
Applied Acoustics
Vol 2 No 3:207-213, 1969
89
-------
04-005
ECONOMIC ASPECTS
The cost is as much a property of a material as
are its physical properties.
The cost means the total cost of the particular
course of action. An example of the importance
of finding the total cost is a London office
block which is being modified at the moment.
It is built on a major traffic route and in
order to reduce the effect of traffic noise the
owners decided to install double glazing.
The double glazing costs $73,000 (supplied and
fixed) and could have been installed with little
inconvenience to the office staff. However, as
double glazing really works only when it is
closed, air conditioning was also necessary,
bringing the total expenditure to $624,000 and
causing considerable disturbance to the office
staff. Thus the total cost is probably ten
times the direct cost of the double glazing.
After calculating the cost the next step is to
compare it with performance in a meaningful
way.
There is a scale already in use for evaluating
things which are essentially different in
character and it is well established and
widely used; money.
It has proved possible to calculate the values
which people put on subjective things. It has
been done for the particular case of houses
subjected to noise, etc. and in principle could
be used for any loss of amenity.
The example in Fig. 1 shows how this kind of
evaluation might be used in deciding what
action too take over the noise from a motorway.
Of the five possible measures considered three
cost vastly more than they would save in
amenity value and may be eliminated from further
consideration. The remaining two possibilities
appear to be worth while.
BASIC CONSTRUCTION FORM
(AT -GRADE MOTORWAY)
f=^ 1==T SB' 3 s' -"r^t 1=^:T
K 600' ."li" , 600' >(
Method of
noise
reduction
" — ^_ 1
10(1 *cr»*ni
T__T
!S 1 rtic-n*d titling
-i^^J"
15rt r«-s f*d t-Uing
JSL
:v;;f., 6 —
»ii'°""_n
I.CII
noise
reduction
5 dBA
C dBA
11 dBA
404BA
30dBA
$^°b'o'o"le
130
5,220
5,350
13,050
390
amenity
va'.ue
fi nnn
310
390
700
1,300
522
KiB
LXc of cost and perfor
The office modification mentioned earlier
provided an example of this. During "the
preliminary tests it was found that the noise
level with the windows open for ventilation
reached about 74 dBA in the front offices.
Simply closing the original windows reduced
this to 61 dBA, which was easy enough to
measure. However, when a secondary window
was installed the level dropped to 54 dBA and
internal noise (doors slamming, conversations
in the corridor, etc.) became noticeable.
The next step in the test was to seal the
outside window as well. This brought the
traffic noise level down to 49 dBA and
measurement became almost impossible because of
the internal noises, which followed one another
in an almost continuous sequence.
The internal noises were caused by hundreds of
acts of minor thoughtlessness and by minor
defects in the construction of the
partitioning and in the maintenance of the
building. Noise from such sources would tend
to give rise 1o dissension among the occupants,
whereas traffic noise coming from outside the
building had a unifying effect and provided a
bond between people in adjacent offices.
Consequently it was decided to leave the
windows unsealed. In addition a sum of money
was earmarked for dealing with internal noise
problems as they became apparent.
A fact which is often missed is that noise is
not necessarily a bad thing; sometimes it can
be very desirable.
04-005
Hurlburt, R. L.
Inglewood Department of Environmental
Standards, CA
105 East Queen Street, Zip 90301
AIRCRAFT NOISE EFFECTS ON PROPERTY VALUES
Inglewood, CA,
City of Inglewood, FEB, 1972, 2 H.
A study of property values in Inglewood, CA,
showed that residential land values are
approximately 50? higher, and rental dwelling
vacancy rates approximately 50% lower in areas
where aircraft noise is less than 80 PNdB
compared to areas where aircraft noise exceeds
110 PNdB.
The results were computed by a linear regression
analysis of data from the Inglewood General
Plan, Prelimirary Housing Element. The data
from 21 census tracts, comprising the entire
city of Inglewood, were used for land values
and vacancy rates. The corresponding noise
levels used were those at the approximate mid-
point of each census tract. Three possible
correlations with noise levels were studied:
residential lend values, vacancy rate of
90
-------
05-001
BUILDING ACOUSTICS
rental dwelling units, and vacancy rate of a I
dwelling units. The first two correlations
were significant at the 5? level.
Variable Regression R:computed R05 Coef.
Y=Land equation
value in (corrputed!
$/sq ft
or vacancy
rate i n %
correlation required for
coef. sign i f icance
at 5?
conf i dence
level
Resi dentia I
land val ue
($) r=5.02-.024x
0.5489
A I I dwe Ming
vacancy rate
(%1 Y=0.22+0.43x 0.2766
0.456
0.433
Rental
dwe Ming
vacancy rate
(%) Y=-1.29+.067x 0.4427 0.433
05-001
Sulewsky, J. E.
Goodfriend-Ostergaard Assoc., Cedar
Knolls, NJ
7 Saddle Rd., Zip 07927
ACOUSTICAL DESIGN GUIDELINES FOR OFFICE
LANDSCAPING
Sound and Vibration
Vol 5 No 6:17-18, 1971
at least 3/16 inch thick, to eliminate noise
such as foot shuffling. Ceilings of "normal"
construction (thin mineral acoustical tile)
are not sufficient because their Noise
Reduction Coefficient (NRC), a measure of
average sound absorption, is only about
0.65 or less, but modifying the ceiling by
adding vertical baffles of glass fiber panels
can bring overall ceiling absorption up to
NRC 0.95. Other successful ceiling treatments
have included:
1) a flat ceiling of glass fiber panel with
an NRC of 0.95; (2) an open light grid panel
with a plenum above it made of vertical
baffles or flat glass fiber ceiling panels;
3) coffer or modified baffle ceiling systems
made of glass fiber panels. Because lighting
fixtures are assumed to cover 25 percent of
the ceiling area, their light diffusers
should be of the open rather than solid
type.
Walls, partitions and columns should be covered
with sound-absorptive materials such as fabric-
or vinyl-covered perforated glass fiber
panels. Carpeting can also be used if pile
depth is at least 3/8 inch on jute backing.
Window draperies are essential; with 150
percent fullness and semi-open weave, they
may still be translucent enough for exterior
objects and colors to be defined. Screens
should be placed to eliminate line of sight
paths between seated personnel at different
work stations and around noisy equipment.
They should work most efficiently in the
250-2000 Hz range, which is the crucial
range of speech and business machine spectra.
They should be at least 2i inches thick, have
an impervious membrane in the middle to reduce
noise propagation through the screen, and have
equal thickness of sound-absorptive material
on either side.
Open plan office arrangements are becoming
increasingly popular, but there can be problems
in providing necessary speech privacy between
work stations and in eliminating disturbing
noise from office equipment.
The three main principals that can prevent
significant loss of acoustic privacy are:
11 jse of carpeted floors and sound absorbing
materials on ceiling and room surfaces that
could reflect sound from one work station to
another;
2! placing acoustic screens between work
stations and around noisy office equipment;
3) adding background masking sound through a
loudspeaker system to cancel transmission of
word information between work stations.
Carpets on + loors should have a pile height
of at least 0.156 inch and either be carried
on a separate sponge rubber or hairfelt pad
or have an integral sponge rubber backing
Background masking sound is produced
electronicly through loudspeakers hidden in
or above the ceiling. Its frequency spectrum
is designed to match that of speech and
although it is audible, its level and
composition are such that it does not sound
''noisy'1 to personnel. Its purpose is to
increase speech privacy by reducing
intelligibility of speech propagated between
work stations. The background noise system
must be tuned after it is installed by
adjusting the level and spectrum of the
speaker system for the optimum combination
of masking and quietness.
91
-------
05-002
BUILDING ACOUSTICS
05-002
Heebink, T. B.
United States Dept. of Agriculture, Seattle
EFFECTIVENESS OF SOUND ABSORPTIVE MATERIAL IN
DRYWALLS
Sound and Vibration
Vol 4 No 5:16-18, 1970
Results of field measurements of four wall
specimens in a small apartment building showed
that urea formaldehyde foam and mineral wool
were effective sound absorptive materials in
wood-frame party walls. Light-weight walls
can thus be provided with a Sound Transmission
Class (STC) number of 50 or more.
The foam used was the patented Isoschaum
Process type. Its three components are urea
formaldehyde resin, a foaming agent and air. It
was applied in the spaces between studs before
the walls were faced with gypsum board. It
firms in about one minute but continues to dry
for one or two days. The eellular
charcteristics are 60? open cells. The foam
is nontoxic, self-extinguishing, non-corrosive,
mold-resistant, and has a density of about 0.6
Ibs per cubic foot.
The walI construction was double 2x4 studs and
plates with a space of 1/2 inch between both
studs and plates. This was faced with 5/8 in.
fire-rated gypsum board.
The four different filler treatments and
their results were as follows:
Field-tested STC
1) Wa I I fi I led with foam on
both sides (foam 7 in. thick) 52
2) Wall filled with foam on
one side (foam 2^-5 in. thick) 50
pI us resi Iient channels under
one gypsum facing.
3) A 2 in. blanket of mineral
wool in stud spaces on both
sides of the wall (total
thickness: 4 in.), plus 47
i in. sound deadening board
under one gypsum face.
4) WaI I f i I Ied wi th foam on one
side (foam 2j-5 in. thick) plus 47
i in. sound deadening board
under one gypsum face.
The ratings of the latter two walls were limited
to STC 47 by their poor performance at 160 Hz.
There are other ways to get equivalent acoustic
isolation in double-stud walls. One way uses
thermal insulation as the filler material and
uses either resilient channels or sound
deadening board under the gypsum board on
both sides of the wall.
The in-place cost of urea formaldehyde foam
is higher than that of thermal insulation (in
the Seattle area). Full-thick foam (6-7 in)
costs 30 cents per square foot and half-thick
foam (2j-5 in.) costs 16 cents per square foot
installed.
Similar investigation, made on the floor ceiling
construction, showed that 6 in. of foam or 3
in. of mineral wool, together with the other
components of the construction, produced about
the same isolation. All measurements were
made according to ASTM standard E336-67T,
"Tentative Recommended Practice for Measurement
of Airborne Sound Insulation in Buildings."
05-003
Verges, L. F.
Verges Consulting Engineers, Downers Grove,
IL
5209 Lee Ave., Zip 60515
WINDOWS—THE WEAK LINK?
Sound and Vibration
Vol 5 No 6:19-21, 1971
For windows in exterior walIs of bui Idings
near airports, a systematic design approach
includes forecasting the noise exposure,
determining the required insulation, and
only then choosing adequate materials and
construction details. Adequate design
knowledge for external windows has existed
for years. Construction providing adequate
noise protection near airports is 15-20$
more expensive than ''standard" construction.
Builders' and clients' insistence on
exterior windows cause the most serious
problems for the designer, because the
window, especially if operable, is the
''weak link'1 in the wall construction. For
this reason, many critical buildings near
airports have no exterior windows. If
exterior windows must be used the design
method below is sufficiently reliable for
small projects. For large scale projects
professional acoustical help is a good
safeguard.
To determine the probable external noise
exposure from aircraft, the straight-Iine
distance to the nearest airport apron
position (not to the edge of the airport
or to the nearest runway) must be
determined.
92
-------
05-003 (CONT.
BUILDING ACOUSTICS
The designer determines background
noise levels acceptable for the various
rooms from the table below. 'Background"
level does not include the sounds of
human activity, but includes ventilating
noise, lighting hum, sound of air
conditioning units, plus noise coming in
from outside. The table below is based on
thousands of measurements of what people
will accept, within reasonable limits of
confidence (approximately 90?).
Maximum permissible interior background
levels in dBA
Type of
Bu i 1 d I ng
Hotel
or
Mote 1
Ai rport
Te rm i n a 1
Fac i 1 i ties
Office
Bui 1 di ngs
Room Max. Permissible
Interior Background
Level s-dBA
Bedrooms
Meeting Rooms
Offices
Lobby
Shops
Restaurants
Ticketing Areas
Restaurants
Main Waiting Room
Loading Gate Areas
Executive and
Pri vate Offices
45
50
50
55
55
60
60
60
70
70
45
General Office Areas 55
Lobbies 55
Shoppi ng
Centers
Schools
Apartments
Lobb ies
Stores
Restaurants
Classrooms
Gymnasi urns
Audi tori urns
Bedrooms
Kitchens
Living Rooms
Hospitals Patient Rooms
& Activity & Social
Nursing Homes Rooms
55
55
60
50
60
40
40
60
50
45
55
Next the acceptable interior level is subtracted
from the anticipated exterior noise level to
determine the exterior wall isolation required.
For example if exferior noise wi I I be at
least 87 dBA (from Figure 1), and the
interior background level for a motel bedroom
should be no higher than 45 dBA (from the
table), 87 minus 45 indicates a 42 dB barrier,
and the window must provide at least that
isolation. Sound Transmission Class (STC)
numbers for various types of window systems
provide a good approximate method of choosing
the correct window treatment even though they
were originally developed to provide a single
number rafings for interior partitions. For
example, if 42 dB external isolation was
required, it could be provided by a window
system with an STC 42 rating.
Sound Pressure Level (dB A)
-nSSSSSSg
G. 1 .
\
^
s;
v
100
Distance to Loading Apro
\
s
X.,
k
1
1000 ' '
Position at Airport (Feet)
V
10,000 *
The table shows that a single pane of glass with
ordinary glazing is a poor sound barrier.
Spaced, double or triple glazed assemblies do
much better, but only if the space between
panes is more than one inch. However, normal
glazing procedures often do not provide air-
tight edges, leading to severe acoustical
leaks unless installation is closely supervised.
Another draw back to spaced window systems is
their expense, bulk, and maintenence problems
(interior soiling). The laminated acoustical
glazing consists of multiple layers of thin
glass laminated with thick, soft layers of
polyvinyl-butyrate plastic. The resulting
total pane thickness ranges from i" to over one
i nch.
Sound transmission class ratings
for various types of glass
Class Type
STC
Single Strength
Double Strength
V," Plate
V4" Plate
1" Plate
1" Insulating, lk" air space
Yt" Safety
9/32" Laminated Acoustical
W Laminated Acoustical
Spaced units, with air spaces from 2" to 4"
19
21
26
31
34-37
32
31
35-36
38-40
38-46
In general, however, there should be no
operable windows used, whether of the hopper,
double-hung, or casement type, if performance
better than STC 32 are needed. If building
codes reguire operable hoppers, the hoppers
should have double or triple edge gaskets, at
least two can-type handles or catches, and
close tightly under considerable pressure.
Even better, they could be made only
technically operable—that is, openable only
by a custodian with a wrench.
93
-------
05-004
BUILDING ACOUSTICS
05-004
Nylins, S.
Saab-Scania, Sodertalje /Sweden/
In: Jansson, P.G., Conferences in Connection
with the International Air Pollution Control
and Noise Abatement Exhibition, Joenkoeping,
Sweden, SEPT 1-6, 1971
Joenkoeping, Sweden, 1971, 525p. (p. 7:100-
7:106)
In this report an engineer from Saab-Scania
Sweden gives the motor manufacturer's
views of the part played by production
env i ronmentaI poI Iut ion.
During the past ten years, the need for
active measures in the field of environment
protection has become increasingly pronounced
and this in turn has led to a rapidly growing
proportion of development work being
concentrated on making motor vehicles more
suitable for the environment.
When talking about noise made by vehicles,
it is important to use figures obtained by
the same methods of measurement. ISO has
issued instructions as to how the measurement
of vehicle noise shall be carried out. When
regulations are drawn up it is extremely
important that they conform to international
standards. There may be good reason for some
extremely large centers of population to
introduce special regulations.
Local sources of pollution can also be
brought under control by means of traffic
engineering and road planning.
The most difficult vehicle noise to combat is
the noise made by diesel-engine vehicles.
Although common belief is that exhaust noise
is most dominant, modern silencers have
brought exhaust noise below a level that
would add to the total noises.
Noise from the combustion process passes via
the engine crankcase to the surrounding air.
This noise is difficult to subdue. Another
source of noise is the cooling fan, the
noise level of which increases with engine
rpm. Induction noise used to be difficult
to control, but this is now silenced to such
an extent that it no longer has any effect
on the total noise level. The difficulty of
suppressing noise is emphasized by the fact
that very little is gained by silencing one
source of noise. The noise occurring at
speeds as low as 40-50 km/hr begins to have
an influence on the total noise level.
Less than 3% of the total number of vehicles
in Sweden consists of heavy vehicles. Due
to traffic restrictions and other traffic
engineering measures, noise from heavy
vehicles has been further restricted.
Buses, on the other hand, are among the
vehicles that" are frequently driven in
residential areas. Saab Scania has
designed a city bus with a noise level no
higher than 74-76 dBA, according to -the
ISO method o* measurement.
Another example of the work done in reducing
noise is that represented by the refuse
collection vehicles developed. By using low-
speed hydraulic pumps for driving the
machinery and by the use of special
insulation around the engine, gearbox and
refuse handling unit, Saab-Scania can make
refuse collection vehicles with a working
noise level cf around 75 dBA.
Heavy trucks can be driven quiter if they
have larger engines. One of the reasons for
this is that a more powerful engine enables
the truck to be driven in a higher gear.
This in turn means that engine rpm will be
lower at an equivalent road speed.
Present-day society is completely dependent
on road transport. For all parties concerned
it is therefore of utmost importance that
regulations governing these important
environmental questions are of a uniform
shape and that technical and economic
considerations are not ignored.
05-005
Kihlman, T.
Chalmers University of Technology
Goteburg /Sweden/
TECHNICAL CONSTRUCTION METHODS AGAINST NOISE
In: Jansson, P.G., Conference in Connection
with the International Air Pollution Control
and Noise Abalement Exhibition, Joenkoeping,
Sweden, SEPT 1-6, 1971
Joenkoeping, Sweden, 1971, 525p. (4:29-4:34)
Propagation of industrial noise by means of
design changes and extra devices on machines
is discussed. It is necessary to use
technical construction methods against noise.
If a source of noise is out of doors, the
reduction of noise with distance is most
effective over the first few meters. Large
reductions in noise require large protective
distances and in general noise from a source
out-of-doors reaches very far.
The intensity of reflected sound can be
affected by absorbents in the room. By
providing a room with good sound absorbents,
the level of the reflected sound can be
decreased by 5 to 10 dB, and a decrease of
94
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BUILDING ACOUSTICS
05-006
this size is not insignificant since it
implies a reduction of 25-50? of the
intensity actually heard.
Noise problems in industry cannot be solved
by means of sound absorbing material,
especially since the sound level near the
source where the direct radiation dominates,
is unaffected by absorbants.
Much larger reductions can be achieved by
means of sound-insulating construction that
is airtight. The most simple door in an
apartment has a sound insulation of about 15
dB. The sound insulation of a 15 in thick
concrete wall is about 50-55 dB. With frame
wall constructions, within a range of 7-15 cm
in thickness, sound insulations in the range
30-55 dB can be achieved.
Sound screening arrangements use screen as
high as possible, placed as near as possible
to the source. In typical situations this
can give reductions of about 5-10 dB at
medium and high frequencies.
Vibration insulating of machines is often
necessary because of noise. It involves
standing the vibrating source on springs.
In this way the transmission of vibrations
to the foundation is reduced above a certain
frequency. It is necessary that the
foundations be heavy and rigid.
When technically planning industries and
industrial premises with respect to noise
problems, these guidelines can be followed.
Noisy machines and processes should be
separated not onty from those activities
which require silence, but above all so that
one avoids exposing more individuals to noise
for longer periods than one must. For
industries which have appreciable parts of
their activities out of doors, much can be
gained by screening and by enclosure.
Industrial premises should be provided with
effective sound absorbents. The absorbents
must naturally be suitable for the particular
environment and be suitable from a practical
point of view. The size of sound insulating
constructions is not generally a problem, but
physical presence can be restrictive. This
can mean that industrial premises should be
made somewhat larger so that space is
available for dividing walls between various
parts of the operations. Finally, with
respect to vibration insulation, even this
starts at the constructional planning stage.
Building planning in general and constructive
design in detail are important here.
05-006
Gardinier, R. E.
Nordby, K. S.
Si Isbee, D. L.
International Business Machines, Endicott, NY
ACOUSTICAL FOAMS FOR SOUND ABSORPTION
APPLICATIONS
Sound and Vibration
Vol 4 No 7:12-16, 1970
The physical and acoustical properties of
polyurethane foams were investigated for
sound absorptive wedge applications for semi-
anechoic rooms. (Wedges, several ft long, are
used on walls and ceilings of acoustical
measurement chambers to make the inside
surfaces of the chamber as completely sound
absorbtive as possible; sound is bounced
back and forth in the spaces between the
wedges, and practically none is transmitted
back into the main chamber space.)
Polyurethane wedges can give better
acoustical performance than glass fiber
Although most of the investigation concerned
the wedge application, with emphasis on low
frequency performance, some aspects of the
results are of general interest.
There are many types of foams on the market,
of varying rigidity. Polyurethane flexible
foams can be divided into polyester and
polyether. types. The following table
compares their physical properties:
Criterion Polyether Polyester
Hydrolysis
Ultraviolet
Air f low
FIammab i Ii ty
More stable
in h urn i d
envi ronment
More durab le in dry
env i ronment
More stable; used
almost exclusively
by garment industry
Max 90? Max
open eel Is
open eel Is
Cost
Fatigue
Neither type self-extinguishing,
except with additives at time
of foaming. The flame retardent
additives lower the air flow
resistance. Without additives
polyester is less flammable.
Less expensive
More durable. Used
for seat cushions.
Air flow resistance is the most important
parameter in determining the sound absorptive
95
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06-001
MEASUREMENT
characteristics. It depends on the number
of cell membranes present and the size of the
cells. Polyurethane foam is an open cell
foam, with relatively few membranes present.
For the wedge application, a cell count of
45-50 per linear in is best.
Foams are easily obtained in densities of
1.0-2.5 Ibs per cu ft, and as specials up
to 8.0 Ibs per cu ft. Most of the special
properties found in the denser foams do not
seem to improve acoustical absorption,
however.
Foams can be obtained in almost any color,
but u-v light, sulphur dioxide, and nitrous
changes cause discoloration toward a light
yellowish brown. If the foam is initially
colored light yellowish brown, therefore, it
will be less likely to show changes over
time.
Although foam making is still as much as an
art as a science, it is possible to obtain
foam with specific mechanical properties.
Flat sheets of foam can exhibit a 95? normal
incidence sound absorption above the frequency
where a 1/4 wavelength is shorter than the
foam thickness. To increase absorption to
99%, wedge shapes must be used to make the
bulk impedance increase between air and foam
more gradual.
06-001
Oesterreichischer Arbeitsring fuer
Laermbekaempfung
1012 Vienna, Stubenring /Austria/
TECHNICAL NOISE PROTECTIVE CONCEPTS AND
MEASUREMENTS
Laermschutztechnische Begriffe und Messungen
OAL-Richtl inie
No 20, DEC, 1969, 7p.
A detailed definition of sound and loudness
and terms used in their measurement are
presented. It is noted that at present,
instrumentation alone is not sufficient for
technically accurate measurement of noise.
It also requires a working knowledge of
acoustical principles. It is suggested that
only equipment recommended by the
International Electrotechnical Commission
be used for measurements. A I ist of such
sound level meters is given below. It is
further recommended that equipment be
inspected by the Federal Bureau of Standards
and Measures every 2 years.
Measurements, as prescribed by the guidelines
for particular noises, should be taken at
least 1.2 meters above ground when performed
outside. Inside rooms, they should be taken
at 1.25 meters above the floor, in the center
of the room. The area in which the
measurements are taken should be free of
people and obstructions, and the microphone
should be located distant from the observer.
Weather condifions should be taken into
account for outside measurements. For
example, wind can influence the noise level by
10 dB.
Manufacturer 1 EC-Pub I. Filter
& Type
Measur.
area
for A
curve
Weight
in kg
Bruel & Kjaer
(Denmark) Type
2205
2206
2207
2203
Imulse-
SPM2204
123
179
123
179
179
A
A
A
A
A
,B,C
,B,C
,B,C
,B,C,D
32-140
37-140
54-140
19-134
15-150
0.
0.
0.
2.
2.
,8
.8
,8
7
7
Peekel N. V.
(Netherlands)
Type GRA
& buiIt-in octave
band fiIter 123
General Radio Co.
(U.S.A.) Type
1565 A 123
1561 179
Rhode & Schwarz
(Germany) Type
ELT BN4514 179
Phi Iips N. V.
(Netherlands)
Type PM 6400 123
L.E.A. (France)
Type SST 2 123
A,B,C 20(25)- 4.7
150
A,B,C 44-140 0.8
A,B,C 31-1501 2.5
A,B,C 55-120 0.6
A,B,C 38-130 2.1
A,B,C 24-140 1.5
96
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06-002
MEASUREMENT
06-002
Baade, P. K.
Carrier Corp. , Syracuse, NY
COt-ilROl OF NOISE FROM MACHINERY
In: Crocker, M., Proceedings of the Purdue
Noise Control Conference, JUL 14-16, 1971
Lafayette, Purdue Univ., 1972, 594p. (p. 81-83)
Proposed methods and problems encountered in
efforts to measure noise from machinery are
discussed. The need to standardize methods
for this measurement is stressed, as are
differences in the requirements for different
kinds of machinery and applications.
There are alternative ways to present sound
data for a specific machine in five separate
areas.
1) Sound power versus sound pressure:
piessure describes conditions at the listner
location, power is necessary in accounting
for different transmission conditions.
2) Single number versus spectrum: data
for noise control must provide frequency
information. Octave band spectra generally
are sufficient by 1/3 octave band spectra
may be necessary.
3) Frequency weighting: the A-scale is the
simplest and most common. However, other
weighfing methods, which correlate better with
subjective judgements of unsteady noises and
sounds, may be better suited for labelling
of consumer products. >
4) Increments and accuracy: the increments in
which noise ratings are given must be consistent
with the accuracy of the measurements on which
they are based and with human reaction scales.
5) Certification: it is desirable for sound
ratings to be certified and policed, which
can only be done effectively by trade
associ ations.
06-003
Botsford, J. H.
Bethlehem Steel Co., PA
Zip 18016
PROPOSED AMERICAN STANDARD FOR COMMUNITY NOISE
At: American Association for the Advancement
of Science, 138th Meeting, Philadelphia, DEC
29, 1971
Bethlehem, PA, Bethlehem Steel Co., 1971, 4p.
A working group of a subcommittee of the
American National Standards Institute (ANSI)
has developed community noise standards for
community sampling procedures and for equipment
noise measurement, and is planning to draft
a model noise ordinance.
This group, the Working Group on Measurement and
Evaluation of Outdoor Community Noise, was
established by the Sectional Committee on
Bioacoustics of ANSI. The ultimate goal
is to achieve maximum human privacy from
intrusion by noise. The first step toward
this goal is the capacity to define the
acoustical quality of the environment
in terms of prevailing noise levels in a
reliable and repeatable way. A simple,
inexpensive technique is needed that may
be used by the non-specialist. Therefore,
an A-weighted sound level meter was chosen,
to be used on the slow meter response. One
problem in measuring community noise is that
it varies considerably with time because
of aircraft, vehicular traffic and other
variable noise sources. To get a repeatable
estimate, the following procedure is suggested:
The A-scale reading is observed for five seconds
and an estimate of the central tendency is
recorded, as we I I as the range of the meter
deflections. Readings are repeated until the
number of readings equals or exceeds the spread
in decibels of all the readings. The average
of a I I the readings will be considered the
community noise level for that location.
Observations should be carried out under
similar conditions on each of three different
days. At least five different locations must
be measured before readings may be considered
typical of a neighborhood.
The equipment noise measurement standard
proposes a test-site method for determining
the maximum noise emitted by public conveyances,
motor vehicles, including recreational
equipment, and construction and industrial
machinery. The test site consists of a flat
outdoor area with no reflecting surfaces or
obstructions within 150 feet. Seven categories
of equipment each have specific operating
instructions to insure maximum noise output
during testing. These categories are broad
enough so that almost any device will fit into
one of them. The A-weighted sound level meter
is used on the "fast response".
Vehicles that travel over 10 mph are tested
while moving. They are driven by the microphone
at a distance of 50 feet with wide open
throttle at near-maximum engine rpm. The
gear is chosen so that the speed stays under
35 mph. The vehicle passes by in both
directions, and only data from the noisiest
side is used.
Other equipment is tested at a standstill
while being operated at maximum noise
conditions. The sound level is measured
around a circle 50 feet from the equipment,
and the highest sound level is recorded.
To insure repeatibi Iity, the same method
97
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06-004
MEASUREMENT
is used as for community noise readings.
When a given model of equipment is being
type tested, different units of that model
are tested until the number tested equals
or exceeds s range in decibels of the
individual ,• results, and the average is
then taker - ie maximum sound level of
that mode 's method is intended for
certifica 'Sting by the manufacturer and
conformanc .I1 ing by communities, but is
not Intends^ :or enforcement purposes
except at a qualified test site.
The standards described above are still in
the draft stage, and the Working Group is
now revising them to meet some objections
that have been raised.
06-004
Puzyna, C.
TRAFFIC NOISE
Halasy Komunikacyjne
In: Zagadnienia Akustyczne w. Zakladach
Przemyslowych
Warsaw, Wydawnictwo Zwiazkowe Crzz, 1971
311p. (p. 136-141)
Measurements were conducted throughout the
various streets of Warsaw to determine the
noise levels. Narrow streets, like "Zabkowska",
with width of about 20 meters containing
buildings with 4-5 stories high registered
noise levels up to 78 dB. Wide streets like
'Plac Uni i Lubelskiej" which is 120 meters
wide and contains buildings up to 7 stories
manifested levels of 64 dB.
Studies were also conducted on greenbelts
containing various trees and shrubs. The
results showed that greenbelts with taller
trees and thicker shrubs reduce the noise
levels considerably. For instance, 2 rows
of poplars, 7 meters high and planted 3
meters apart, with a row of fruit trees and
a living fence in front of them, totaling
15 meter depth of the greenbelt, can
reduce the noise level up to 30 dB (with
trees containing leaves), and 18 dB-
(without leaves).
A method for noise reduction of streetcar noise
is the "wetting" process of tracks. Results
showed that noise levels from tracks on concrete
ranged from 82-85 dB after wetting, 73 dB on
asphalt background and 60 dB on a concrete
plate with elastic insulation. These
measurements were taken at a 7-10 meter distance
with the streetcar going about 25-30 km per
hour.
The author suggests installments of street
microphones which will register excess noise
levels by special monitoring. This method
will aid the abatement program.
Warsaw, like any other city, considers traffic
noise next to industrial noise, its biggest
noise source.
The first step in noise education should be
undertaken in city planning and siting. Also
greenbelt and parks, according to the author,
can prove to be the most effective abatement
device. They should be constructed along the
main arteries, along street-car and
railroad tracks and in all heavy traffic areas
of the city. Any type of a green oasis should
also be considered an essential for school and
hospital areas.
Another source of noise abatement should be
time restriction put on certain railways.
The highest noise levels are emitted by trucks,
streetcars and motorcycles, for instance:
Type of vehicle
Streetcar
Tractor (No. Ursus 45)
Truck
Trolley car
Motorcycle
Bus
Passenger car
Noise level in dB
63-78
84
77
75
76
75
60
Measurements were conducted at a 6 meter
distance.
06-005
On: PNEUMATIC EQUIPMENT NOISE TEST CODE
Sound and Vibration
Vol 5 No 2:4, 1971
A recently prepared test code specifying
standard techniques for measuring sound from
pneumatic equipment covers both portable
equipment such as hand-held pavement breakers
and trai lor-mounted air compressors found on
construction sites, and stationary equipment
like large rotary vane compressors found in
industrial plants. The document, "CAGIPNEUROP
Test Code for the Measurement of Sound from
Pneumatic Equipment,1 was developed by the
Compressed Air and Gas Institute (CAGI) in
cooperation with the European Committee of
Manufacturers of Compressed Air Equipment
(PNEUROP).
98
-------
MEASUREMENT
06-006
In the code, pneumatic equipment is divided
into three classes: 1) small machines, both
percussive and non-percussive; 2) large
portable equipment; and 3) large stationary
equi pment.
Two types of measurements are taken, A-weighted
sound levels and octave band sound pressure
levels, at each of five or more specified
locations one meter from the outline of the
machine. For large portable equipment,
readings at 7 meters are also required.
During measurements, the equipment must be
stationed above a hard plane (e.g., a concrete
floor) and operated under specified loads.
Noise radiated from any loading device used in
conjunction with the equipment must be at least
10 dB lower than that from the equipment, to
insure that only the latter is being measured.
One measurement problem in enclosed areas is
reflected sound. The code solves this problem
by specifying that the levels at the
measurement point be at least 6 dB greater in
each octave band than levels measured at
points more distant from the equipment.
Another measurement problem dealt with by the
Code is the likelihood of large errors when
strong pure tones are present; these errors
occur because of interference between direct
sound waves and those reflected from the floor.
This problem is solved by moving the microphone
vertically over a range of 30 cm above and
below the measuring point, at a rate of at
least once over the path per second, while the
measurement is being made.
Calculation rules and standard test data forms
are provided in the Code, which has been
submitted to International Standards
Organization (ISO) and American National
Standards Institute (ANSI) for approval as a
standard.
Noise in the home is not just an acoustical
problem; it is economic and social as well.
Legislation on noise control is not needed as
much as is the cooperation of industry in
manufacturing quieter machinery.
In order to achieve this cooperation for
effective noise control, information is
needed in three categories:
1) equipment sound ratings
2) proper application and installation of
equi pment
3) appropriate noise levels for specific
situations
Standardized methods of sound rating have
been started by the Ai r-Condi t ioni rig and
Refrigeration Institute (ARI), which is now
publishing a directory containing acoustical
ratings of outdoor condensing units.
It has also published an Application Standard
to aid the buyer to use these ratings for
selection and application of air-conditioners.
These ratings should aid both the buyer and the
manufacturer find should spread in their
applicability to other machinery and equipment
as we I I .
ASHRAE (the American Society of Heating,
Refrigeration, and Air Conditioning Engineers)
is updating its Standard 36 and is working on
the development of international standards.
Social and economic factors enter the fie'd of
noise control. Individual tolerance of noise
and willingness fo pay for its control also
have to be considered.
The publication of universal noise standards
is a step in the right direction, but the
price and performance of quiet equipment will
have to be improved, too.
06-006
Baade, P. K.
Carrier Corp., Syracuse, NY
Research Division, Zip 13201
HOUSEHOLD NOISE PROBLEMS
Journal of the Acoustical Society of America
Vol 50 No 5:1232-1235, 1971
This article discusses recent standards for
performance ratings and application information
of the Air-Conditioning and Refrigeration
Institute as an example of what an industry can
do to communicate acoustical data between
manufacturers, ins+aliers and users.
06-007
Hurlburt, R. L.
Owen, D. A.
Inglewood Department of Environmental
Slandards, CA
105 Easr Queen St., Zip 90301
PERMANENT MICROPHONE MONITORING SYSTEM
In: Hurlburt, R. I., Inglewood's Noise
Monitoring Program. Report on Phase I
Inglewood, CA, City of inoiewood, SfPT 30, 1971
33p. (p. 5-8, 38)
99
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06-008
MEASUREMENT
A description of and results obtained from a
four-point automatic noise monitoring system
in Inglewood, California is presented. The
system measures noise from aircraft taking off
and landing at nearby Los Angeles International
Airport. The four remote microphones are bolted
to telephone pol«- ^rossarms about 25 teet above
the ground and are connected via brcadcast-
quality telephone lease lines to City Hall,
wher° the data is processed.
"fr",-,f~ 'pi points monitor ro'i-e oon + i nj jus i v
to show U..ng tern rioise B/posure trends. The
microphones are rain and wind protected, with
an integral calibrating system. Upon command
. 1000 h. -icj'iMl magnetically drive;, the
microphone equivalent to a sound pressure level
o' 90 dB.
At City Hall information is displayed on a
Noise Exposure Monitor that presents the
total time that noise in the area around
each mioiophone exceeds thresholds of 30, 90,
and 100 dBA.
"fher modes of data presenta+'on are available.
1) An unweighted signal played to r?,pe 'ecorder
enables o record c c the noise it'-el* to be kept,
and also a ."> rcade if
desired.
2) The unweighted noise car, be monifored with
loudspeaier to check if it iray be caused by
some source other than airp. lanes, such as
+rucks or motorcycles. In pract ce, noise
above 90 dBA usually comes from aircraft.
31 The ,-V-weighted noise is played to a
graphic recorder which plots it against time,
this permitting calculation of CMEL (Community
Ncise E^Dosure Level) fiau^es.
was checked out during a mor1toning
eotember, 1970. Also in December,
clerical consul ring firm did a more
ed analysis of nine recorded flyover
no. computer calculation techniques
suits in dBA, SENEL, and EPNI units.
results in dBA correlated «i"hin 2
ewood's data, showing that
system correlates ve'~y wH I with
oated measurement techi' iqu -AJ
06-008
",eh i , '
Innersoll-Rand Research, Inc., Princeton, NJ
Instruments used for sound measurement and
the function of each are discussed. The
basic instrument is 1 he sound level meter.
It consists of a nonairectionaI microphone,
a calibrated attenuator, an amplifier, an
indicating meter, anc weighting networks.
The meter reading is in terms of root-mean-
square (rms) sound pressure level. The
instrument cannot measure the peak level
of high-speed sounds, as those produced by
hammer bfows, punch presses on gunshots.
Special i ns n umen t a f i o> \f require' f°r su'i-h
appIicat ions .
Usually, three weighting networks are included
in these instruments—A, B, and 0. Originally
ihe A network was to be used for sounds below
55 dB, tne B network for sounds between 55 ana
85 dB, and C for levels =bove 85 dB. The
A network gives a very good indication of the
loudness of sounds regardless of the level
and is most irnporrant. Ihe C network is
essential ly flat, arid sounds read with if are
called sound pressure levels. AM freguency
analyses mus+ be measured on the C scale.
The A network reported as dBA fa I Is of^
sharply at lov/ frequencies, to correspond to
the response of the par. The microphone is
the most important part of the sound-
measuring iris r.Jmen1 a 11 jn . frequency response,
sensitivity, directio la I ity, and range are
primarily determined ^y the microphone.
The octave-band analyzer is the most common
analyzer for ndustrial noise measurement. it
separates the complex noise into frequency
bands one octave in width, and measures the
level in each of the bands. Narrow-band
analysis must be performed when the source of
a noise component must he identified for
purposes ot sound reducfion, or some other
reason, for ~hese analysis, half-octave,
third-octave and tenth-octave analyzers are
used.
An acoustic calibrator fits over the
microphone and calibrates the entire system
of microphone, attenuator, amplifier, and
meter. The microphone should be shielded by
a wind screen when wind veloci ly is high.
Noise recorded for analysis in the laboratory
can be analyzed with various band-width
analyzers, displayed on a graphic chart, and
retained for other purposes if desired.
However, recording supplements, rather than
replaces, Directly measured d^ta.
Microphone placement depend^ upon objective,
noise at a workers ear, of a cornpresser
inlet, e+c. /it each of !"he microphone
locations, the following data 'houid be
Taken with the machine operating: 1)
oprnll sound level using rhe A-woig-i * i rg
network; an.', .:' oc. tave-baiid sound pressure
levels using Ihe flat response or C network.
A similar set of data, background noise,
should be taken at one ot the locations wirh
the machine shut down. A sketch should be
made showing the mct<-!ii nc , locations of other
100
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06-009
MEASUREMENT
machinery building walls, and microphone
locations, as well as a description of the
machine and operating conditions.
Certain calculations are required to
interpret data taken in sound tests. It is
often necessary to combine sounds made by
different machines, or even octave-band
data measured on the same machine.
Background noise often must be subtracted
from the total noise to obtain the sound
pressure level of a machine alone.
06-009
Diehl, G. M.
Ingersoll-Rand Research, Inc., Princeton, NJ
THINK QUIET: PART IV—NOI SE CRITERIA
Compressed Air Magainse
Vol 76 No 5:12-13, 1971
Preventing community complaints about noise
from industrial sources is discussed. Criteria
to prevent annoyances are more restrictive than
criteria to prevent hearing damage or speech
interference. Annoyance depends upon the
level of the offending noise compared to the
pre-existing background level, its absolute
value, its frequency, how it varies with time,
and whether it occurs during the day or night.
While it is impossible to predict exactly the
response from any particular neighborhood
to any specific noise, a fairly reliable
method has been developed by Stevens,
Rosenblith, and Bolt. One can plot the
measured octave band sound pressure levels on
Figure 1 to determine the initial level rank.
The highest zone into which any of the octave
band levels penetrates is the level rank of
the noi se.
RESIDENTIAL NOISE LEVEL
Corrections are next applied as follows:
CONDITION CORRECTION
Pure-tone components +1
Wide-band noise 0
Impulsive +1
Not impulsive 0
Continuous exposures, to
1 per mi nute 0
10-60 exposures per hour -1
1-10 exposures per hour -2
4-20 exposures per day -3
1-4 exposures per day -4
1 exposure per day -5
Very quiet suburban +1
Suburban 0
Residential urban -1
Urban near some industry -2
Area of heavy industry -3
Nighttime 0
Daytime only -1
No previous conditioning 0
Considerable previous conditioning -1
Extreme conditioning -2
•The sum of the various corrections then is
applied to the original level rank to obtain
the corrected level rank. The expected
community response can then be predicted by
Figure 2.
COMMUNITY RESPONSE TO NOISE
Community
Action
Threats of
Community
fiction
Widespread
Complaints
Sporadic
Complaint*
No Observed
Reaction
c d e f g
COMMUNITY NOISE RANK
Figure 2
NOISE CRITERIA (Nc CURVES)
OCTAVE PASS BANDS (HI)
MTTT
NOT RECOMMENDED
ANY OFFICE
^ LARGE
-1 FNUNFERiNG
D DRAFTING
--- — - ROOMS
-.«, PRIVATE OFFICES
63 125 250 500 IK 2K 4K BK
OCTAVE-BAND CENTER FREQUENCY (Hz)
Figure ]
Figu.a 3
101
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06-010
MEASUREMENT
A widely used set of noise criteria for various
offices, conference rooms, residences, and the
like was developed by Dr. Leo Beranek (Figure
3.) The International Standardization
Organization also has recommended a similar
set of criteria, called NR (Noise Rating)
curves. The National Electrical Manufacturers
Association (NEMA) has produced a set of noise
criteria for gas turbine installations.
Precautions should be taken when using dBA
levels. The popularity of A-waighted sound
levels is increasing rapidly as a means of
expressing all types of sound criteria, whether
it be hearing damage, speech interference
levels, community annoyance levels, or
machinery acoustic performance. However, it
should be remembered that dBA levels must
be used with caution; whatever noise control
must be engineered, octave band data are
needed. Sound should be combined on an
octave band basis only, and not by adding
or subtracting overall levels.
06-010
Organization for Economic Co-Operation
and Development, Paris /France/
Consultative Group on Transportation Research,
2, rue Andre-Pasca I
URBAN TRAFFIC NOISE: STRATEGY FOR AN IMPROVED
ENVIRONMENT
Paris, OECD, 1971, 166p.
An Organization for Economic Co-Operation
and Development report recommends international
abatement measures for traffic noise. The
sponsoring committee set two goals for public
policy: to prevent further increases in traffic
noise, and to roll back present levels at an
economically, technically, and politically
feasible rate. Limits on maximum noise at the
source should receive priority over limits on
method of operation because they automatically
bring more widespread benefits. Source limits
should be at levels consistent with the
technology available at the time, but should
be made more stringent as improvements in
technology permit. Governments should promote
production of quieter vehicles by specifying
them in their procurements, and with
progressively more stringent limits that
will encourage research and investigation of
alternate urban transportation modes which
offer a long term solution to the problem.
Measurement techniques should conform to
International Standards Organization (ISO)
recommendations. Governments should encourage
control of traffic noise by urban planning
and highway engineering techniques such as
rerouting noisy traffic, better traffic flow
to minimize noise from acceleration, zoning
and land-use planning, location of new major
roads to take advantage of existing natural
acoustic barriers, more use of tunnels and
open cuts, better location and sound insulation
of housing, and development of alternative,
quieter modes of urban transportation.
Since motor vehicles move in large numbers in
international trade, government regulation of
vehicular noise limits should be internationally
compatible. The work done so far by the
Economic Commission for Europe (ECE) and the
Common Market (EEC) is clearly only the first
step. Any internationally agreed-upon limits
should encourage reduction from current levels
and not merely underwrite the status quo.
Three chapters of technical background
information summarize the nature of the
urban traffic noise environment, effects of
traffic noise on man, and methods of control.
The chapter on the urban environment discusses
the predominance of urban traffic noise, its
peak/background structure, specific noise
sources, and noise level factors (weather
conditions, night driving, natural barriers,
speed, flow, ard density of traffic).
The chapter on effects of traffic noise
discusses subjective effects, speech
communication, interference with sleep, effects
on learning and task performance, and immediate
and cumulative physiological effects.
The chapter on noise control discusses source
modification by vehicle type and subsystem;
operational modification such as rerouting,
limitation of night operation, improvement of
traffic flow; transmission path modification
such as road design, noise barriers, proper
siting of buildings, and zoning; and
architectural modifications such as window
treatments and interior bui iding layout.
There are two Annexes. Annex One contains
current administrative and legislative
practices of OECD member countries Canada,
France, Italy, Japan, Netherlands, Denmark,
Norway, Sweden, Switzerland, and the United
Kingdom.
Annex Two presents the directives of the
UN (ECE, Geneva) and the Common Market
concerning maximum noise levels from
veh i cles.
102
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MEASUREMENT
06-011
06-011
Williams, C. E.
Pearsons, K. S.
Hecker, M. H.
Naval Aerospace Medical Inst., Pensacola, FL
Zip 32512
SPEECH INTELLIGIBILITY IN THE PRESENCE OF
TIME VARYING AIRCRAFT NOISE
Journal of the Acoustical Society of America
Vol 50 No. 2:426-434, 1971
A discussion of the large number of complaints
made about aircraft noise and its disruptive
effect on speech communication suggests that
a measure of speech interference may be
useful for evaluation of the annoyance of
ai rcraft noise.
Usually the level at only one point in
time (the peak level) or the average sound
pressure level, is used to predict the
amount of speech interference that would
occur during an aircraft flyover. Since
the sound-pressure level and spectral
contents of an aircraft flyover change with
time, such predictions are often inaccurate.
A meaningful definition of speech interference
should take into account both the degree to
which speech is masked by aircraft noise and
the duration of such masking.
For various kinds of steady-state noises,
the amount of speech interference produced
is uniquely related to the Articulation
Index (Al). There is some question,
however, as to whether relations established
for predicting speech intelligibility in
steady-state noise can be applied without
modification to a situation involving time-
varying noise. The objective of this study
was to determine whether the relation between
speech Intelligibility and Al for time-vary!ng
aircraft noise is different from that for
steady-state noise.
The results show that, for a given Al, the
time-varying noise masked speech less than
the steady-state noise.
The magnitude of the difference cautions
against the use of relations established for
steady-state noise to predict speech
intelligibility in the presence of time-
vary ing noi se.
It is concluded that the relation between
word intelligibility and Al for time-
varying aircraft noise is different from
that for steady-state noise. There n\\\ be
an appreciable disruption of contextual
speech when the peak level of an aircraft
flyover exceeds 88 PNdB, an SIL (speech-
interference level) of 68 dB, or an A-
weighted sound-pressure level of 76 dB.
06-012
Cohen, A.
Anticaglia, J. R.
Carpenter, P. L.
Department of Health, Education 8, Welfare,
Ci nci nnati , OH
National Inst. for Occupational Safety and
Health, 1014 Broadway, 45202
TEMPORARY THRESHOLD SHIFT IN HEARING FROM
EXPOSURE TO DIFFERENT NOISE SPECTRA AT EQUAL
DBA LEVEL
Journal of the Acoustical Society of America
Vol 51 No 2:503-507, 1972
This study seeks some clarification of the
adequacy of dBA measures for rating hearing-
loss risks for assorted noises which may
display broad differences in spectral,
temporal, or other acoustic features. Its
specific intent was to test whether sound-
level readings in dBA could suitably depict
the harmful ness to hearing from exposures to
noises differing greatly in spectral shape.
Three test noises having spectral slopes of
6 dB/oct, 0 dB/oct, and +6dB/oct provided
the test conditions of interest. These three
noises were presented at a constant 100 dBA
level in three separate 30 min exposure
sessions to each of 11 male subjects, and
then presented again to the same listeners in
three additional retest sessions. Figure 1
shows the spectral shapes of the three noises
at the prescribed 100 dBA sound level. Also
noted in Fig. 1 is the frequency response
curve for the A-weighting network. It is
relatively insensitive to low-frequency sound
energy. This weighting curve is most biased
against the energy contained in the noise with
the 6 dB/oct slope.
Temporary threshold shifts in hearing served
to evaluate the degrading effects of the
different noise spectra on the ear. Such
hearing thresholds were measured for pure-
tone frequencies 250, 500, 1000, 2000,
3000, 4000, 6000, and 8000 Hz. Each tone
was presented for 30 sec in which fime the
subject controlled the attunuator so as to
fluctuate about his threshold level for that
sound. The attenuation rate was 4 dB/sec.
During the postexposure test, the listener
was allowed to stabilize his 500-Hz threshold,
beginning at 1-1/2 min after noise cessation,
the actual posrexposure test commencing at 2
mi n.
Temporary-tnreshold-shift data for the various
pure-tone frequencies were corrected to
postexposure measurements at 2 min,
abbreviated as TTS2.
103
-------
06-012 (CONT.
MEASUREMENT
If dBA is a satisfactory indicator of noise
hazard to hearing it would be expected that
equal dBA exposures to the test noises,
despite their spectral variations, should
cause equivalent amounts of TTS2. Spectral
differences among the noises caused no
statistically significant differences in
threshold shift wh.-sn pooled for all pure-tone
frequencies. Over-all TTS2 means for the
various noise spectra were nearly identical
with mean differences less than 0.5 dB.
However, significant interactions between
noise spectra and pure-tone test frequencies
were also found. At pure-tone frequencies
below 3000 Hz, frequencies above 3000 Hz, the
reverse was true; the +6 dB/oct noise caused
more threshold shift than the 0 dB/oct noise
which, in turn, caused more TTS2 than the -6
dB/oct noise. The -6 dB/oct noise is more
harmful to hearing than the other two test
noises for equal dBA exposures. Perhaps the
weighting curve for dBA is too severely biased
against low-frequency energy, and thus does
not adequately take account of its degrading
effects on hearing relative to that caused by
high-frequency sound. The +6 dB/oc slope
noise should be most harmful to hearing
followed by fhe -6 dB/oct slope noise and the
flat spectrum noise.
In short, dBA ratings of noise hazards to
hearing may be discounting too much low-
frequency energy. Except for one procedure
which simply averaged the sound levels of
octave bands with midfrequencies 500, 1000,
and 2000 Hz, other noise rating schemes using
spectral determinations did not improve on the
amount of TTS2 produced by the test noises of
variable spectra.
&3
"?50 500 1U03 ?OOC 400O 6000
BArD CIMER FREQUENCY 'N HZ
100-dBA NC'SE WITH RISI'v. SPECTRUM
125 25O 500 IOOO 2000 «OOO 8000
FREQUENCY IN HZ
SOUND-LEVEL METER A-B-C FREQUENCY RESPONSE
104
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06-013
MEASUREMENT
06-013
Langdon, j.
Building Research Station, Garston /England/
TRAFFIC NOISE CONTROL CRITERIA
Bui Id InternationaI
Vol 2 No 6:26-30, 1969
The pecularities of traffic noise are
characterized and the essential pre-conditions
for a useful noise nuisance criterion
outlined. The nature and origin of the
Traffic Noise Index (TNI) developed by
building research studies are discussed,
and comparison is made with the equivalent
noise level (END as an alternative method
of devising such criteria.
Numerous efforts to relate traffic noise
level to human response have failed to produce
measures with real predictive value.
tn order to measure and control traffic
noise nuisance, there are at least three
points to consider. First, noise produced
by traffic is exfremely varied in both
intensity and character. Second, its
propagation is complex and imperfectly
understood. Third, there are great
differences between individuals in the
degree to which they can tolerate noise.
A practical noise control criterion must be
based upon correlations between measured noise
and social nuisance, resulting in a functional
relationship which permits the interplay of
all the relevant variables correctly weighted.
Two methods are discussed: the technique of
the ENL and the method of the (TNI) developed
by Building Research Station. In short, the
ENL is the mean of a logarithmically weighted
summation of all noise levels at 5 dB
i nterva I s .
In developing the TNI, variations of traffic
over 24 hours were taken into account by
noise sampling, over an adequate period, 1)
the relative attenuation bases by recording
noise at building facades over a wide range
of distances, and 2) individual differences
by using a sample large enough to obtain a
normal distribution. A multiple weighted
correlation was obtained to enable prediction
of social nuisance with fair accuracy over
the range of noise climates.
In comparing the two measures, the TNI gives
greater weight to peak noise as against
background levels, whereas the ENL tends
to give weight to situations in which
high noise levels will prevail. Also,
the TNI gives better predictions of
nuisance and disturbance of sleep during
the evening and night than between hours 1-5
in the morning. This is important because
most sleep disturbance due to noise occurs
during the first hour of sleep.
Both indices have their advantages and
shortcomings. The most important requirement
for noise control, given the measure of social
nuisance, is to reduce the peaks and surges in
traffic noise.
Purely physical scales will not be useful in
noise control, since they measure only the
intensity. Only indices such as the ENL
and the TNI assess the degree of disturbance.
07-001
Department of Housing and Urban Development,
Washington, DC
AIRPORT ENVIRONS: LAND USE CONTROLS
Washington, HUD, MAY, 1970, 35 p.
This environmental planning paper points out
some of the problems, methods and prospects
for solving a variety of aircraft noise
problems facing urban communities.
The comprehensive planning process for
compatible land use and airport development
is directed toward achieving an optimum
relationship between an airport and its
environs. As such, planning for compatible
land use in the airport environs and
planning for the airport itself should be
integral parts of an areawide comprehensive
planning program.
The compatible land use approach must be
related to noise alleviation made possible
through engine modification, aircraft
certification, and revised operational
procedures. All relevant avenues must be
considered and applied to the problem in a
coordinated fashion. Research and development
efforts on methods of reducing noise at the
source and modifying flight paths and
operating procedures to bring about further
reductions should proceed simultaneously
with similar investigations of airport
community land use strategies.
The conflicting pressures for both the further
expansion of the air transportation system
and for urban and metropolitan growth in the
United States are so strong that further
impact ion of airport environs is almost
i nevitable.
105
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07-002
PLANNING & SITING
Therefore, the use of innovative approaches
to land use planning and controls for
development, as well as the proper application
of existing controls, is urgently needed.
Land use controls must apply also to the
airport itself, in terms of maximum acreage
and intensity of use, so that the airport
is compatible with the area in which it is
located and so that changes in the character
of the airport and its operations do not
continually expose new areas to noise. The
costs and benefits of airport development
must be weighed against those associated
with incompatible neighboring uses. Further,
the costs and benefits of "on-the-ground"
and "in-the-air" solutions must be assessed
to develop a total program to reduce aircraft
noise impact.
07-002
Schmidt, H.
6079 Sprendlingen/Hessen, Am Trauben 9
LEGAL MEASURES FOR PROTECTION FROM AVIATION
NOISE
Stand der Gesetzlichen Massnahmen zum Schutz
vor Fluglaerm
In: Fluglaermtagung, Wiesbaden, MAR 17-18,
1969
Wiesbaden, Deutscher Arbeitsring Fuer
Laermbekaempfung, 1969, 2 p.
The Inter-parlimentary Committee, which is
represented by a I I Government factions,
has presented its first draft as publication
V/355 in 1966, dealing with all air-traffic
noise problems. It intended to divide the
vicinity around airports in three noise
zones. The average noise level for Zone I
should be about 72 dBA, Zone II, 67-72
dBA, and Zone III, 62-67 dBA.
There should be no construction of hospitals,
orphanages, retirement homes, sanitariums
and schools in any zone.
In Zones I and II, there should be no new
residences constructed; and Zone III only
residences with good sound-protection.
Finally, it was proposed that owners of Zone III
residences should be granted allowances for
the insulation of their homes, and restitution
for landowners whose land could not be used
for construction.
Financially, this plan was found to be
unrealistic because the cost for the civil
airports would amount to about $630 million
and that of the military-airports $3.15
billion. In September, 1968, a new draft
was drawn up. Now there are only two zones,
Zone I - noise level can exceed 75 dBA
and Zone II 67 dBA. In Zone I, residences can
only be constructed in populated areas with
special insulation regulations. In Zone II,
all new construction requires all insulation
regulations. The cost is carried by the airport
owners, and in case of military airports, by
the Federation.
The cost estimated for the civil airports is
from $10 to maximum $12.6 million, and those
of the military airports between $37-47
mi I I ion.
In addition, airports are required to erect
noise monitoring stations. Also, local
commissions should be established as advisory
organs for the communities. They should
comprise representatives from the communities
surrounding airports, airplane owners,
Federal agency for air safety, and Federal
organization against aviation noise and the
Health Organization.
It is also necessary to enforce certain noise-
reducing measures, especially in respect to
arrival and departure. It is believed that
take-offs and landings can be curbed during
the night time.
07-003
Stacy, E. F.
Building Research Station,
Garston /England/
Dept. of the Environment
Watford WD2 7JR
MOTORWAY NOISE AND DWELLINGS
Building Research Station Digest
No 135:1-7, 1971
Introduction of the "10$ Level" (L10), a
single figure measure of traffic noise
exposure, is proposed for measuring design
purposes. This unit is related to subjective
reactions, in this case dissatisfaction with
traffic noise. The unit gives a fair
correlation with dissatisfaction and makes
the best use of the current state of knowledge.
L10 is the arithmetic average of the hourly
values, over a weekday period from 6 am to
midnight, of the levels in dBA just
exceeded for 10? of the time at one meter
from the facade of a dwelling. The practical
application of L10 to traffic noise control at
housing sites involves obtaining the noise
exposure by direct measurement, by estimation
106
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07-004
PLANNING & SITING
from design data, or by a combination of the
two. The maximum level for LIO recommended by
the Noise Advisory Counci I is 70 dBA. To
apply this standard to all new housing and to
existing houses affected by new urban motorways
is useful in reducing the nuisance of traffic
noise.
Where a road already exists, noise exposure
is measured at the housing site, provided that
no major changes, such as pulling down old
buildings which intervene, are proposed. The
measured noise levels should be adjusted to take
account of any foreseeable increase in traffic
flow on the road. If the motorway does not
exist at the building design stage, noise
levels are estimated. Adverse wind conditions
should be the basis for design purposes,
even though more favorable conditions sometimes
prevai I .
Ground surface that is grassed or planted
(not paved in any form) will absorb energy
at some frequencies from sound waves that
are propagated close to the ground. For
propagation distances greater than about 20 m,
this absorption can reduce the noise exposure
level in a complex manner.
Traffic composition, particularly the proportion
of heavy trucks, sometimes affects noise level.
However, in fairly fast, free-flowing traffic,
heavy vehicles and normal gradients have only a
minor effect on noise levels.
Well-designed noise screens can sometimes
achieve as much as 20 dBA reduction, although
10 dBA would be more typical. It is an
advantage to put it close to the noise source,
to make it as high as may be practicable and
of adequate length. Buildings may themselves
be used as noise screens for screening other
buildings. However, the noise levels behind
the screen building itself, close to the facade
facing away from the road should take into
account that other buildings can reflect noise
back to the otherwise shielded facade.
To be effective, tree belts must be wide and
dense. A width of at least 50 m is necessary
to give a reduction of about 10 dBA, and a high
proportion of the trees and shrubs must be
evergreen if the protection is to be
maintained at all times of the year.
Every building gives to its occupants some
measure of protection from external noise. The
noise level inside an uninsulated dwelling,
away from the windows, should be at least
10 dBA less than the outside level. If the
external level of 70 dBA cannot be met, it
may still be possible to restore a satisfactory
acoustic environment indoors by improving the
sound insulation of the structure.
A method has been proposed for estimating
L10 due to free-flowing traffic for a
range of circumstances. This exposure
level provides a basis for planning against the
noise from urban motorways. Until more
knowledge is obtained, it is suggested that
the same procedures may be useful for other
free-flowing traffic.
07-004
Kraege, R.
Institut Fuer Schall- und Schwingungstechnik,
2 Hamburg 70, Fehmarnstrasse
AIRPORT NOISE AND ITS CONTROL
Flughafenlaerm und seine Bekaempfung
In: Fluglaermtagung, Wiesbaden, MAR 17-18, 1969
Wiesbaden, Deutscher Arbeitsring Fuer
Laermbekaempfung, 1969, 2p.
This paper discusses abatement measures
taken to reduce the noise from an air-freight
terminal in West Germany.
Initially an embankment was planned to be
planted with trees and was found to be
unsatisfactory due to the time it would
take for them to grow. A sound protection
wall was constructed at the airport boundary and
all freight handling sections were confined to
a large hangar. By these means the noise level
was reduced about 13 dBA at the adjacent
residential area.
07-005
Lane, S. R.
California Univ., Los Angeles
School of Arch, and Urban Planning
Zip 90024
FREEWAY AND HIGHWAY NOISES: AN INFORMATION
BASE FOR URBAN DEVELOPMENT DECISIONS
Springfield, VA, NTIS, PB204434, 1971, 90p.
HC: $3.00 MF: 95 cents.
In the 30 by 50 mi le core area of Los
Angeles there are 350 mi les of freeways
causing almost continuous noise levels of
70-90 dBA in the five block wide strips on
either side. Because of this, most new
proposed freeway routes meet active opposition
from the communities that would be affected.
Criteria should be developed for compatibility
of transportation routes with human activity;
107
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07-006
PLANNING & SITING
these criteria would relate the costs and
benefits of noise reduction to impacted
communities.
Data for Los Angeles are presented for
residential population densities, freeways
and traffic volume patterns, leading to
calculation of the number of residents near
freeways.
Cars and trucks on freeways are then
considered as noise sources, and together
with other considerations such as surface
street traffic noise and noise reduction in
buildings, this information is used to specify
zones of intrusion. Data from other U. S.
cities and from the United Kingdom are
i ncorporated.
Much past work done on subjective response to
motor vehicle noise has not succeeded in
giving an accurate picture of the degree of
annoyance individuals actually experience in
the contextual situations of their various
daily activites. One reason for this
failure has been the artificiality of the test
setting and the limited number of subjects
used; another reason is that the descriptors
of degrees of annoyance were chosen by the
experimentor. The research done by the
Building Research Station in the United
Kingdom avoided some of these pitfalls by
using survey methods in actually impacted
residential areas.
Criteria for acceptable residential noise
limits from various sources, including the
City of Inglewood Ordinance, and various
standards widely used in Switzerland, England,
and the Scandinavian countries are
compared with each other, and with noise
levels implicit in the California Vehicle
Code.
It is concluded that about one million people
currently live within four blocks of a
freeway in Los Angeles. Traffic noise is
likely to exceed 75 dBA within one or two
blocks of a freeway, and 60 dBA within four
blocks. The latter figure is about 10 dBA
above urban residential background levels
where there is no high level noise source.
The freeway system will problably double
to 750 miles by 1980. Exact delineation of
impacted zones will require detailed surveys,
because of complex sound propagation
patterns caused by variations in shielding
and reflection. There is a need in Los
Angeles for a noise data system commensurate
with the current level of effort in other
environmental activities. Community
resistance to expansion of the freeway system
has already been effective, forcing
government and the transportation industries
to account for the costs of noise production.
A comprehensive decision/allocation system
is needed to deal with the problem.
07-006
Dobson, D. E.
South African Council For Scientific
and Industrial Research, Pretoria /S.
Africa
NOISE ABATEMENT: THE NEED FOR A MULT I -
DI SCI PL I NARY APPROACH
Municipal Administration and Engineering
Vol 36 No 430:1971
The first committee on noise abatement in
South Africa was established in 1969 by the
Johannesburg City Council. The committee
has not only concentrated on Johannesburg's
municipal problems, but has resolved to
form a national coordinating committee to
deal with noise in all municipal areas as
well .
In addition, there is a call for a multi-
disciplinary approach to a I I forms of
pollution, in which cooperation and
coordination of various pollution
organizations are the keynotes.
Ekistics, or the science of human
settlements, must be an integral part of
architecture. As far as this relates to
noise abatement, consideration must be
made for factors affecting outdoor urban
noise, such as spacing between buildings,
as well as silence within the buildings
themselves.
Other ekistical schemes include creating
areas of the city which are relatively
free from motor traffic at certain times of
the day, designing quieter motor vehicles
and construction equipment, and asking for
government grants to encourage program
development.
The cooperation of business interests is
essential. In addition, an emphasis must
be put on the individual citizen's role in
noise abatement by being quiet, cooperative,
and considerate.
The noise pollution problem has been recognized
by the parent organizations of the neighborhood
schools and they in turn have sent expressions
of their feelings to the local school board,
city, state, and Federal governmental bodies
in this regard.
The following suggestions are made in
reference to any proposed standards:
1) Well established criteria include some means
of limiting noise at any time, even for short
duration, to 85 dBA minimum. Energy averaging
or similar integration procedures probably do
tend to predict hearing damage, but they do not
define annoyance, nuisance, or other subject
effects.
108
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07-007
PLANNING & SITING
2) It is simple to measure noise levels in dBA
with simple, low cost equipment, which can be
operated by competent law enforcement
personnel; or to automate such measurement
quite simply.
3) It is simple to forecast noise exposures on
the ground whenever airport configuration and
aircraft type and operational procedures are
known. Thus, it is possible, without any
measurement procedure at all, to establish the
operating parameters of aircraft, the airport
layout (especially runway direction and
orientation), and to determine zoning areas
near the airport in advance.
This would tend to preclude the need for much
of the proposed complex measuring procedure;
and it would go a long way toward avoiding the
nuisance of noise.
A reduction in speed from /O mph to 50 mph
would reduce the sound level by about 4 dBA.
The economics of doing this for long-distance
rural motorways could be investigated but
would undoubtedly be unpopular, even if shown
to be econom i c.
Urban main roads include commuter, bus and
commercial routes. In general, both flows and
speeds are moderate, but the noise is increased
by the starting and stopping at traffic signals,
rotaries, pedestrian crossings and other
interruptions. Distance is not available as
an alleviator and in many circumstances
barriers would be unacceptable. Alleviation
from noise must therefore be sought by
reducing the flow as far as possible and by
smoothing it out to achieve moderate but steady
speeds, by the use of clearways, over and
underpasses, etc. In these respects the
means of noise reduction seem quite compatible
with other aspects of traffic engineering.
07-007
Burt, M. E.
Road Research Lab., Crowthorne /England/
ASPECTS OF TRAFFIC DESIGN AND TRAFFIC
MANAGEMENT
Journal of Sound and vibration
Vol 15 No 1:23-24, 1971
This discussion is centered on three types of
road: 1) through motorways: 2) urban main
roads: 3) residential roads. In general,
noise increases with the traffic flow, with
the steady speed, and with the degree of hill
climbing and acceleration. All three are
clearly correlated with the type of road
concerned.
For through motorways, a reduction of 10 dBA
in the average sound level would require a
reduction in flow from 10,000 to 1,000
vehicles/hr. For a flow of 10,000 vehicles/hr,
a six-lane road would have to be replaced by
ten 3-lane roads operating near their maximum
economic flow. The cost per vehicle/km would
be increased and the resulting nuisance from
the numerous smaller roads might well be
worse than that from the roadway itself.
In rural areas, noise is likely +o be a problem
only where the motorway passes near towns or
particular buildings. In general, therefore,
distance can be used as an alleviator, possibly
aided by the use of trees in suitable areas.
In sensitive rural localities, and more
generally in urban areas, the policy clearly
seems to be to use motorways to their
capacity and to provide noise protection
by use of sound barriers or by environmental
planni ng.
An experiment in area traffic control was
made in which 80 signalized Intersections in
central Glasgow are brought under computer
control. Various control strategies are
being tested, and results to date indicate
an improvement of 10-13% in journey time? over
the pre-existing system, with a probable
reduction in noise. No "before and after"
noise measurements were made.
The provision of noise barriers by means of
walls, embankments, or cuttings, raises a
number of problems. If a roadway has a waI I
placed near the edge of the shoulder, the wall
will be struck occasionally by vehicles, and to
avoid casualties it will have to have the
qualities of a good crash barrier or bridge
parapet. It must present a smooth surface
to the vehicle and must be strong and stiff
enough to deflect the vehicle back along trie
roadway so that the driver has some chance of
regaining control. The ends should be tapered
to avoid "gust" effects on cars caused by
s i de winds.
Roads in Britain are wet for about one-quarler
of the time, and skidding plays an important
part in accidents. At low speeds the friction
between +he tire and the road surface is
affected by the material and the fine texture
of the surface, but as speeds increase a
rough surface is required for adquate braking.
This tendency \s unfortunately adverse as far
as noise is concerned. "Grooving" the concrete
surface to improve skid resistance produced
high frequency noises in one test.
The Traffic Noise Index (TNI) is an advance in
that it draws attention to the importance of
the range of noise levels in addition to the
upper and lower limits. But as the range to
be expected from a proposed new road wiI I no+
be known in advance with any certainty, and
indeed may well change with time, it may be
difficult to use the TNI as a design criterion.
Assuming that in many cases some reduction
in noise level is desirable, the following
broad conclusions are reached.
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07-008
PLANNING & SITING
1) On mdjor through motorways reduction of
traffic noise by control of traffic flow,
speed or composition is unlikely to be viable.
It may be necessary to accept the generated
noise and alleviate its effects by barriers
or environment design.
2) On urban main roads, carrying mixed traffic
whore there is a conflict between transport
and environmental considerations, some reduction
in flow should be sought, and traffic management
techniques used to encourage modest but steady
traffic speeds.
3) In residential and other areas where a quiet
environment is the dominant consideration, it
may be necessary to discourage through traffic
and take measures against individual noisy
vehicles.
4) ihe incorporation of noise barriers into the
highway does not present serious engineering
problems, but snow removal problems are
possib!e.
5) Developments in road surfacings need
investigation from the point of view of noise.
07-008
Kui fu, H. G.
Minneapolis-S1. Paul Metropolitan Airports
Commission
JET NOISE AND ITS IMPACT
Airport Services Management
Vol 12 No 10:16-18, 1971
The evolution of the jet noise situation in
the Minneapolis-St Paul area (Wold-Chamberlain
Field) and the efforts of the Minneapolis-St.
Paul Airports Commission (MAC) to deal with
it are described. Persistent and organized
opposition to jet noise came in 1967-68,
as exemplified by news stories reflecting
public concern. In 1962, MAC established
a Noise Abatement Committee, whose members
included representafives of the FAA, airlines,
the Air Transport Association, and the Airline
Pilots Association. Positive results included
the introduction of a visual approach slope
indicator (VASI) with the minimum approach
slope angle first set at 2.7 degrees (1966)
and later at 3 degrees, advisory signs on the
runways reminding pilots of take-off procedures
to minimize noise, and new traffic patterns
directing aircraft away from populated areas.
In response to increased public concern the MAC
staff prepared a comprehensive report in 1967-
68, which concluded that a solution to the local
noise problem was not possible until Federal
regulations limited the noise of the aircraft.
The MAC actively supported such legislation
in the following period, writing to each member
of the Minnesota Congressional delegation and
briefing two members of the Senate Aviation
Subcommittee on the noise problem faced by
the airport operator.
In 1968 MAC created the Metropolitan
Aircraft Sound Abatement Council (MASAC) to
provide continuous study of the problem and to
advise MAC.
A positive feature of Wold-Chamberlain is that
cleared land at the end of instrument runways is
far in excess of federal requirements (one mile
or more; the FAA requires 2,500 ft). However,
volume of traffic at the airport has increased
from 1.4 million passengers in 1956 to 4.3
million in 1967. Use of terminal air space
will increase 10 times in the next 30 years.
Retrofitting of the present generation of jet
aircraft is advised, because NASA studies
indicate that the cost of not retrofitting is
greater than the costs of retrofitting, if one
considers costs of alternative methods to
reduce noise around airports. Alternate
methods include expensive land acquisition
contiguous to present airports and reduction
of airport capacity. The latter results in
increased operational costs to airlines
caused by delay in departing and arriving.
It is suggested that the aviation industry
and the general public share the cost of
retrofitting. Moving airports to isolated
locations is not feasible because this method
defeats 1he goal of providing fast and
convenient transportation and also because
such airports only remain isolated for a very
short time. New economic activities generated
by the airport attract people who soon begin
the crowd the airport boundaries.
There is presently worldwide opposition to
expansion of airline facilities. The noise
of the jet engine is used as a catalyst for
arousing anti-airport attitudes. Without
quieting of the jet engine source, maximum
efforts by airport owners and operators will
not be enough to prevent strong community
reaction.
110
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07-009
PLANNING & SITING
07-009
Townend, D. S.
British Petroleum Co.,
London /England/
Britannic House, Moor Lane
London E.G.2
NOISE FROM PLANT AND EQUIPMENT—AN OIL
INDUSTRY APPROACH
Annals of Occupational Hygiene
Vol 14:101-107, 1971
The Oil Companies Materials Association (OCMA),
a British association of oil companies, has
developed specifications that will enable the
prediction of plant noise levels, both within
the plant and also for noise emissions to the
community. These specifications enable the
oil company to require builders and suppliers
of equipment for new plants to provide noise
data in their bids in a standard, comparable
way. They have been used by British
Petroleum Co. for some time in draft form,
and Esso Petroleum has used similar
specifications for about 5 years. The
specifications are:
NWG-1 Procedural specification for limitation
of noise in plant;
NWG-2 Noise limitation for individual items of
equi pment;
NWG-3 Guide to the setting of limits and use of
NWG-1 and NWG-2.
NWG-2 consists of the excerpts of NWG-1 of most
interest to suppliers bidding on petroleum plant
projects. While manufacturers' representative
bodies often seek limits set in dBA for
simplicity, OCMA felt that at least octave band
data were needed for the effective design of
new plants.
Part 4 of NWG-1 contains a system for dividing
the entire plant area and environs into four
types of areas for the purpose of setting
Iimits:
G—general work area limits
R—restricted exposure work area limits
S—speech and work interference limits
C— community area limits.
Part 5 gives standard forms for equipment
noise limits that can be used by the plant
operator equally well in the case of user
designed plant or contractor-designed plant.
Part 2 of NWG-1 details standard noise
measurement procedures; Part 3 gives standard
calculation methods to be used. These standard
calculation methods—one for large and one for
small equipment—are not scientifically precise
but experience has shown that they are
sufficiently accurate to meet the demands of
plant situations. For plant design work and
for calculating the total effect of an array
of installations at a point distant from the
plant, the approach of Part 3 is to measure
sound pressure levels around sources, convert
to sound power figures for each source, and
combine the individual power levels to get a
total power level that can be converted to
sound levels at distant points. The
calculation method for predicting noise to
the community considers not only ground
absorption, but also two degrees of screening.
The plant operator must go through three
important steps for controlling noise. First,
he must decide on limits for the four types of
areas mentioned. In some countries limits
already imposed by authorities decide this
for him; otherwise he must decide for himself
on the basis of "good neighbor" and "good
employee relations" considerations.
Second, he must have a way to break down the
limits he has chosen into limits for individual
items of equipment that can be passed on to
suppliers and manufactures.
Third, he must have a standard for measuring
the actual noise performance of the completed
plant as compared with the specified limits,
so that it may be objectively determined
whether guarantees by contractors or suppliers
have been met. The OCMA Specifications give
the plant operator the tools to accomplish
steps two and three.
Insofar as guarantees are concerned, the
principle is that the user/operator takes
responsibility for remote area noise, while
the plant designer/contractor takes
responsibility for meeting limits within the
plant area. This principle has also been seen
in operation in other industries, but not in
a forma Ii zed way.
07-010
Anderson, G. S.
GottemoeI lor, F.
Bolt, Beranek, and Newman, Inc.,
Cambridge, MA
URBAN HIGHWAY PLANNING FOR MINIMUM NOISE
At: American Association For the Advancement of
Science, Philadelphia, DEC 29, 1971
Cambridge, Bolt, Beranek, and Newman, 1971, 7p.
Noise control through highway design is
discussed.
In Baltimore City a screening procedure has
been developed that combines the distance to
the projected highway with estimates of future
111
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07-011
PLANNING& SITING
traffic flow and speed to predict a new
highway noise level - both its average level
and its degree of fluctuation. These
predictions are then compared to noise design
goals derived from land use and estimates of
the existing noise. Using this procedure, ten
neighborhoods in Baltimore have been spotlighted
as potential problems.
Four case studies on Baltimore neighborhoods
are discussed. Highways were designed for
noise control by use of earth berms, transparent
acryllic shields, and corrugated steel barrier
waI Is.
Noise control designs for projected highways
in the North-Central and Northeast Corridors
in the District of Columbia should reduce noise
impact from 970 dwelling units to 45; from
325 dormitory rooms to zero; from 11 school
buildings to zero; and from 54 acres of parkland
to zero.
Baltimore City's interstate noise control
should cost $3,500,000 - a large figure, but
only one-half of one percent of the total
construction cost. For the District of
Columbia, the additional construction cost is
estimated between 0.2 and 0.5 percent of the
total project cost, for a sum of $3,600,000
if all sections of the highway network are
constructed. Funding is available from the
federal government for well-designed noise
barriers. The problems of esthetics are being
overcome by the more imaginative designers
who have accepted the chal lenge. What is
primarily needed now is a broader acceptance
of these goals, and a wider application of the
handbook methods.
conveyors when pipes are transferred, pipe
assembly lines, and boring machines. They
produced more than 60-70 dBA at the eight
different measuring points alongside the
residential ares.
The factory studied three possibilities for
noise reduction: 1) suppression of the noise
sources (machines and conveyors); 2) building
a wall between the factory boundary line and
the highway (33.5 meters wide between the
factory and the residential area); and 3)
building a noise barrier alongside the
residential area facing the highway and the
factory. Because of economic factors and
probable hindrance of production, the factory
abandoned all of the possible plans. Instead,
the factory finally came up with the idea of
building a warehouse, which was needed for
storage, and at the same time getting a noise
barri er.
The wall of the warehouse alongside the highway
was 5.6 meters high, and 6 meters from the
factory boundary line. The wall facing the
factory bui I ding was 8 meters wide and 11 meters
high so that fhe warehouse could act as a
barrier between the factory and the residential
area.
After the construction, the noise level
conformed with the environmental standard set by
Noise Abatement Law of 55 dBA during the night
time. Measurements before and after the
construction show the amount of reduction
achi eved.
Measuring Place
Before After
Construction Construction
of Warehouse of Warehouse
07-011
Mugi kura, K.
Kajima Construction Research Institute /Japan/
CASE STUDY OF REDUCTION OF FACTORY NOISE
EMISSIONS
Koojoo Sooon Koogai Taisaku Jitsurei
Sangyoo Koogai
Vol 7 No 5:241-245
Boundary Lines
(1 and 21
Resi dential
Areas (3 to 8)
3
4
5
6
7
Mean Values
63 - 73 dBA 57 - 59 dBA
62 - 71 52 - 55
- 71
53 - 58
64 - 69 53 - 56
64 53 - 57
65 - 72 53 - 57
71 53 - 57
65 - 72 53 - 57
65 - 72 dBA 54 - 57 dBA
As an example of achieving 12 - 15 dB noise
reduction at little extra cost, a warehouse
was built between a residential area and the
factory. The factory which manufactured pipe,
was 140 meters long; the residential area was
70 meters away. The residents were mostly
employed by the factory. Both employees and
residents who were not employees complained,
but the latter complained more. Noise sources
were clankings between pipe and the roller-
112
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07-012
PLANNING & SITING
Bolt, Beranek, and Newman, Inc.,
Cambridge, MA
Washington, Supt, of Documents, US6PO,
SN 2300-1194, 1971, 20p. 70 cents
Paper-and-penci I cak'ilat
presented by the Dept. of
Development (!tUD) for eva
exposure oi a hoiis j ^r, cjt
from aircraft, nearby roa
Designed a*:, a pre! irni nary
guidelines do riot const it
HUD is encouraging their
be evaluated. he site i
four eategories. Clearly
both indoors on;i outdoor"
(som'j i o-. e exn* :, ure, ! u1
with common building tech
pleasant outdoors), Ncrma
(unusual and cos"Iv ionsr
sore i idoor quiet, ,.nd Oa
noi;>e -ourv.e and site no-
on methods are
Housing and Urban
uating the noise
-_• 1o intrudi ng noi so
ds and rai I reads.
sc1oening tool, I he
. fe riUD pol icy, but
.->e so that they may
nIaced in one of
acceptable (pleasant
. 'formally Acceptable
• ,,', ah « i ridoors
iques and reasonably
ly unacceptable
ue f i or _^ reeded for
r K r ^ separating
ed outdoors), Clearly
' ' ^n~ rr-eded for
oxpens oj, and
rolerabIe at any
The ea'^jory dot er r.ii r,-d >oi norse f rcrn the
worst so^r> e is Jeemea the category of the
site, e/ •- tn^ueh the ~'~ o-sori e3 dictated by
noise f r ON 'iher so jr v a, v Owre tavorablo.
The calculation tor • >. . at r noise presupposes
the aval la1, i ' ir, or • ' e oois^ Rating (oTIR)
or Noise exposure Fot <, asi (tCF) cornours for
the nearby (15 rn'ie, . i less) airport, but a
simple method is prox'Jed 4o cor.oiruct
app rox i ma t e feniojre i i <'. ^e a r, dp with CNR
or I-IEF contours can u. bv 17 and
adding llos to the number (jf dayTir:ie operations.
The resulting number • u^ed to lay ou1 the
30 and 40 UEF r--,nt^->jr; jr,.,i,.id 4- - airport's
r u r i w a y s .
I f the s i +e is i rs i -i;
con!oui , i i is C'eur i
between the NEF 30 an
Norma I I y Unaoceptc-D ! •;
outside both the NLL
decision ahout /.nethu
Acceptab 'e or C'> • > '
close i t ; , to i;,
•1-0 NIC F-40 (or CNR-1 15)
, iirtCk' 'ptau le. If it is
40 contour;,, it is
\*Hien "the s i f e lies
- and 40 con tout s, the
it is ,'Jorrna I ', y
''. ceptabL, dc-pends on how
30 cr,,,tou. .
For roadway noiS'",f all major roads within 1000
feet o* the . iK~ -^r- considered separately, and
the worst case -!s the determination of
the category. !_••<. AM se, separate evaluations
are tiade of noise fret;1 autoriiobi les and from
trucks *or tach roadway, and The worst case i .-
cent r c i I i r,q. ro> automobile nr_ise 4"e datr.
required are 1) the effective distance of rni
road from *he iite (a function ct 1 he distartt
from, the s] *e to the center lines ot the noaicj
lane and In farthest lane; th' effective
Distance i - oj off of a nomo/.!'!' /' ' Lo roa*
hourly *loi, o* tratf-c (vot''
directions combined/. Ir trio ^iiipic^. co L-
which assumes a mean vehicle speed of 60 mph,
these numbers are plotted on a araph end The
category ct the sr'o is '^ao t i •' direct!-,.
However, for o^he' sreeds, -:nti f^ir r*- - ' a^ '
like the existence z' shie'-'i'ir tarro.1
stop-and-go tral.ic, appropri-j. ad f
made to ~rne vehM c les-per-hour riuriber betv,r'
is plotted on tne araph. (No CxO,"rectiOn fo~
night-tir.e HI;H :e is offer?'!.)
if 1he nrad:ent is more than j% this fa t rru^r
be taken into ac^o.nt. If fne giauiert i'. ft,re
than (}%, tre ei'.-c+ o4 the cr>l c .i I,,'. io' Piefhod is
to double the ..I'octive, i. uc f.i-[ si-ho i nu,''n, r
actually LiS'-d "io plot the nc i so r'i'fec
The calculation ^ positive stti,o'j i _>, j. ,
shielding barriers (either ..utlings or fer;ce;
and learns) i , r ?(]uired only when the noise
effect is j Poroe' i rie case L -,!.-erir' to
categories. i\, Take an adju *ner.t i O' shielding
' > a r r i c i s , f h >- n, > u t v] a t a ' f ,' 11 • •_ a > .
distane he r vscun The .•..,"< i i . .. r.-,r,.:
and the Darner,
distni";e oetween the s tc .r u -f--,c ,;r , l( ,
._, lev -I t i ,' o f the, • i aow iy
olevar , -,. o: the _ • Te
elevoiio. '-i ihe i'-,p ct the barn
hoi 4h t of :i,e bu, ! i'i', • f - e err •• d
the si;e.
A s i n; ';''•"! , ''---, mot hod, J: ' o
interrelated sets of families of cai y^s oi1
laid out en one work sheet, is provided to aid
in the acttal -r rmuf a f io"
ra i li.ay has more than 10 "i
(10 fir, -7 am) . Tor les; -ii
distances t ron the rai lre,a'
adjusted before tne 4i!,ilc i
A final 0,11 i on,si eve! uat ior ,
Test, i - j .-!•;.!., ,\. i ><- i',_ i
tlit. to1 a i Ticis^ level fr.jri' all
the use or ' "n s pre,suro l-,v
oth^r" -',^iprnci *, no relafi.
accepfan i lit/ I]T ^ ruousing si i
the mea >urerner't. One mian hoic^. readii'i
material ,/i rh A/hioh, f,c,th aro f.imi liar in sucti
a wav ab noi t - hhaoK ;',e ,,CM Between himself
and the other Man. The other" man backs slowly
away as the first man reads aloud, riot raising
his voice MI an attempt to main t.. in
comrnunicat on. 'At the pcin' wneit, Ts'e I 'Stener
can only understand a iCut'e, •'-_ i-oro or I ao
113
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07-013
PLANNING& SITING
over a period of 10 seconds or more, he stops.
The distance between the two men is measured.
Several trials are taken, with the men
changing roles, and the results are averaged.
If the test is performed on the site during
peak noise periods (e.g., during traffic
rush hours) and also at times when the noise
is likely to be least annoying (e.g., between
10 pm and midnight), then the averaged
distances for the worst trial period may be
used to evaluate acceptability:
Distance Where
Understanding
Becomes Very
Difficult
More than 70 ft
26 - 70 ft
7 - 25 ft
Less than 7 ft
Acceptabi Iity
Category
Clearly Acceptable
Normally Acceptable
Normally Unacceptable
Clearly Unacceptable
07-013
Lane, S. P.
California Univ., Los Angeles
School of Architecture and Urban Planning,
Zip 90024
AUTOMOBILE AND TRUCK TRAFFIC NOISE INTRUSION
In: Lane, S., Freeway and Highway Noises:
An Information Base for Urban Development
Decisions
Springfield, VA, NTIS, PB 202434, 1971, 90p.,
(p. 8-42) HC:$3.00 MF:95 cents
A study designed to estimate residential
interior noise levels in Los Angeles houses
near freeways is presented. In order to
determine truck noise and automobile noise as
a function of distance from the freeway,
generalizations were made from data from four
studies in the Los Angeles area and one from
Detroit. Because the reporting formats varied,
adjustments and approximations had to be made.
The reference point for distance was chosen to
be the cenrer line of near traffic flow.
Measurements made from other reference points
were adjusted.
The assumption, substantiated by a separate
Michigan sfudy, was made that peak noise levels
correlafed with truck traffic and the average
of the continuous noise level correlated with
automobile traffic. A composite of various
noise levels as a function of distance from the
freeway follows.
Type of
Source
Sound Path
Distance (from center
Iine of near traffic
flow)
100ft 200ft 500ft
Steady flow Unobstructed 75dBA 70dBA 68dBA
traffic
(2000-4000
per hour
in the Obstructed 62 57 53
near-side
lanes),
avg. sound
level
Freeway truck
traffic, Unobstructed 82 75 68
typical peak
sound levels
(one peak
per truck)
These composites were then used in the
estimation of noise intrusion into the
residential areas.
The outdoor background noise (without nearby
traffic) was taken to be an average of 50 dBA.
Measured background levels for other U.S.
communities were taken into account, as well as
the following data from Inglewood, in the
Los Angeles area:
Location
Time Range,dBA Ave.,dBA
Middle of residential Day 42-56 48
area
Periphery of area Day 52-58 55
Residential area
adjacent to main
roads 5 am 37
Residential area 4 pm 58
Although adequate theories for noise reduction
of assembled buildings are still in the
formative stages, a review of observations made
in several U.S. cities indicated that, in
general, the average noise reduction for traffic
noise of residential buildings is 10 dB with
windows open and 23 dB with windows closed.
In Los Angeles, residential unit lots start at
least 100 feet from the center of the near
lanes. There are about three blocks within
1000 feet (or 1/5 mile) of a freeway. Since
the average outdoor background noise level in
a quiet neighborhood is about 50 dBA, the
interior noise level (windows closed) will be
about 30 dBA. Combining all the variables, it
was estimated that one block from a freeway,
auto and truck noise will cause intrusion levels
of 15-25 dBA. Three blocks from the freeway,
intrusion levels are still greater than 10 dBA.
These estimales apply when the sound path is
unobstructed, e.g., houses located on a street
perpendicular to the freeway.
When the sound path is obstructed (e.g., houses
in the middle of a block on a street parallel
to the freeway), estimated intrusion levels are
about 6 dB loss than those given above.
With windows open, the interior background
noise is about 40 dBA (50 dBA outdoor
background noise level minus 10 dBA noise
reduction of the residential building). Again,
114
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07-014
PLANNING & SITING
intruding freeway noise can cause noise levels
10 dBA above background interior levels within
three or four blocks of the freeway, and greater
than 20 dBA within one block.
The estimates are probably conservative.
Although there were few actual measurements
to compare with the estimates, observed
noise level contours obtained in one
residential area were plotted against the
computed contours because of differences
in attenuation in various sound paths. In
this case, actual observed noise levels were
significantly higher than was expected, perhaps
because of above-average volume of truck
traffic and underestimation of noise on nearby
surface streets.
designs that utilize higher temperature
insulation and smaller, unidirectional fans.
When fan noise is the problem, external
treatment is effective. AcousticaI Iy-lined
fan covers and enclosures are used for
noise control.
Control valves are responsible for nearly all
the noise generally blamed on piping systems.
Valve noise often persists for long distances
For noise control, there are valves with
special low-noise internal design, or inline
silencers. Valve designs which limit the
internal velocity to substantially less than
sonic are most effective. Acoustic lagging
is the least effective noise control because
of the downstream propagation of valve noise.
07-014
Seebold, J. G.
Standard Oil Co. of California,
San Francisco, CA
NOISE CONTROL IN OUTDOOR PROCESS PLANTS,
GENERAL DESIGN CONSIDERATIONS AND SPECIAL
PROBLEMS
In: Crocker, M., Proceedings of the Purdue
Noise Control Conference, JUL 14-16, 1971
Lafayette, Purdue Univ., 1972, 594p.
(p. 163-168)
Corrective measures taken in a noisy plant
after startup are more costly and less effective
than proper design of original plant equipment
as long as you know what to do at the design
stage.
The remote effect of an outdoor plant depends
on the nature of outdoor sound transmission.
The designer has little control over this
problem. However, the designer can deal, to
some extent, with the sound power generated
within the plant.
Intense noise accompanies the high rates of
heat release inside process plant furnaces.
There is a general agreement that combustion
roar is the most serious problem. Combustion
roar, inherent in today's burners, has to be
confined to the firebox. Other design
alternatives for noise suppression lack
practicality, effectiveness, or both.
Fan noise is produced by turbulence created
by blade passage through air. Except for
motor fans, external acoustic treatment is
rarely practical. Designs that minimize
turbulence are used for noise control. Fans
are usually the major source of noise in
air-cooled motors. In large motors
electro-mechanical noise may become important.
Some relief from fan noise can be obtained from
Like valves, compressors produce noise of high
intensity in a frequency range which spreads
easily in the connected pipework. Inlet
and outlet silencers may provide sufficient
noise reduction without total enclosure.
Further technological development is needed
here.
In many piping systems, noise can build up
in the fluid or more can escape through the
pipe, or both, and probably explains why a
normally unimportant noise source is
occasionally found to be a real troublemaker.
Recent studies suggest that for high speed
compressors and valves in gas service, most
of the energy wi I I remain in the gas, and
inline silencers are most effective. For
pumps and valves in liquid service, it appears
that most of the energy is transferred to the
pipe, suggesting that vibration isolation
should be most effective. Flares used to burn
excess process gases can be sources of
community annoyance. In the simple steam
jet, the major source of noise is the highly
sheared mixing zone just downstream of the
nozzle. Combustion noise and light are the
major problems in elevated flares. Flare noise
can be reduced to some extent by using multiport
steam nozzles. The quicker the steam becomes
thoroughly mixed with the inspi rated air, the
less the noise produced.
To be successful today, specifications should
set forth specific minimum design features for
noi se control .
A process plant should be viewed as a noise
producing system. Many sources contribute to
the composite noise levels. For each source,
some noise reduction can usually be had by
several different means, each having its
own effectiveness and cost. This suggests
that a system approach needs to be taken to
' "ist-cost designs.
Where design solutions are available,
corrective measures taken in a noisy plant
after startup are more costly and less
effective than proper design of original
p lant equi pment.
115
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07-015
PLANNING & SITING
07-015
Matheson, W. K.
Wold-Chamberlain Field,
Minneapolis-St. Paul, MN
OPERATIONAL PROCEDURES
Airport Services Management
Vol 12 No 10:19-20, 1971
Operational procedures already carried out at
Wold-Chamberlain Field (Mi nneapol i s-St. Paul)
that have reduced aircraft noise include
reduction of training flights, installation
of more electronic navigational aids, take-off
signs, and partial nighttime curfew. Further
measures under consideration are extension of
the curfew to charter aircraft and the
introduction of special ground run-up areas.
Northwest Orient Airlines and North Central
Airlines, both of which use Wold-Chamberlain
as home base, have cooperated in removing all
training flights except the minimum required
by FAA for pilot certification. Other training
flights use less noise-sensitive airports.
Large yellow and black noise abatement signs
installed at the take-off end of five runways
request pilot's cooperation; signs also serve
as a visible reminder to passengers of the
airport's effort to reduce noise.
Aircraft approaching the airport on the back
course I LS fly over noise-sensitive areas.
The installation of glide slope and marker
beacons on the back course ILS, the first of
its kind in the US, has furnished the pilot
the electronic guidance needed to follow a
3-degree descent slope, insuring higher
approach altitudes than before.
After a public hearing in 1970 showed that
night operations were the primary reason for
complaints, scheduled carriers voluntarily
agreed to limit night flights in the
11 pm-6 am period.
Further noise abatement measures are under
consideration. The night curfew does not
now apply to charter aircraft, which may
legally refuse to accept a noise-preferential
runway and instead take off at night over
heavily populated areas. A proposed field
rule would apply night curfew rules to
charter ai rcraft.
A second proposed measure is the desi
o1 a specific it-cund run-up area chosen m
, i 1 1 i-ii rj ^' j
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07-017
PLANNING & SITING
suggest that in busy urban areas 50 dBA by day
and 35 dBA by night should not be exceeded for
more than 10% of the t i me i ns i de dwe iIings.
Methods of achieving these standards for
existing buildings near motorways may range
from providing openable double windows for
bedrooms only, to sealed double windows for
both bedrooms and living rooms.
The Greater London Council is urging the
Government to recognize for grant purposes
unavoidable expenditure in dealing with the
noise factor and with daylighting and amenity
problems when new motorways are introduced
into 'quiet' urban areas.1
Before motorway M.1 was opened into the
northern suburbs in 1967, a survey in the
residential Mill Hill and Hendon areas was
carried out to establ ish existing noise
levels. Measurements were repeated on the
same day of the week and at the same time.
The main conclusions found were that the
biggest increase in noise levels due to the
motorway occurred at night, up to 14 dBA. In
the case of houses whose back gardens were
3-4 meters above the motorway, the noise levels
dropped rapidly from the back fence to the back
wall of the house, which shows the effectiveness
of route selection combined with taking
advantage of ground contours.
At Heston, M. 4, at a height of 2-4 meters,
passes only 16 meters from typical three-
bedroom semidetached houses. As a noise
abatement procedure, the simple wooden fences
now standing will be replaced by a purpose-built
noise barrier 2.5 meters high and consisting
of a double skin of plastic with an overall
surface density of 12 kg per sq. m.
On the two shorter lengths of motorways within
London, the A.102CM) and A.4CKM), measurements
were also made before and after the opening
of the roads. The most striking results were
found in Tunnel Avenue and Westcombe Hill,
two roads parallel to the A.102(M). When the
motorway was opened, noise levels at the front
of the houses, which faced away from the
motorway, dropped by about 5 dBA (daytime) and
rose by about 5.6 dBA at the rear.
In the case of the A.4CKM), measurements are
not complete. However, in several previously
quiet roads consisting of older 3-4 storey
houses, noise levels of up to 80 dBA were
recorded by day outside windows.
07-017
Zeller, W.
Siepmann, J.
Institut Fuer Schall-und Waermeschutz,
Essen /West Germany/
Krekelerweg 48
NOISE PROTECTION IN A LARGE REFRIGERATION
PLANT LOCATED IN A RESIDENTIAL AREA
Laerm-Immi ss ionschutz bei Einer Groesseren
Kaelteanlage im Wohngebiet
Lae rmbekaemp fu ng
No 2/3:33-35, 1970
The City Hospital in Essen, Germany had to
expand its refrigeration plant to provide
ai r condition i ng.
The neighboring residences were located only
30 meters away in a totally residential area,
where the noise level could not exceed 35 dBA
during the night. Therefore special sound
protection measures had to be used in order
to comply with the prescribed standards.
After two prospective cooler sites (A&B) were
established, considerable measurements were
taken at 6 measuring points in order to
determine the noise levels and thereby the
appropriate location. The noise levels at
cooling tower A at a thirteen (13) meter
distance reached 65 dBA when in full operation.
The background noise there reached 57 dBA.
The Cooling Tower location B showed noise
levels of 63 dBA at a 13 meter distance.
Therefore the noise level had to be reduced
by about 30 dBA by means of damping devices.
Absorbant materials staggered in baffle boxes
on the ducts were chosen. After these devices
were installed, measurements were taken between
midnight and 1 o'clock at night at the nearest
home, with the following results:
Number of
Coolers in
use
Noise Levels
Fu I I Power
(dBA)
Ha I f Power
(dBA)
46
44
42
42
41
117
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07-018
PLANNING & SITING
07-018
Sadowski, J.
Instytut Techniki Budowlane, Warsaw /Poland/
Ul. Wawelska 2
TRAFFIC NOISE IN WARSAW, GDANSK AND POZNAN
Untersuchungen Ueber den Verkehrslaerm in
Warschaw, Danzig and Posen
Lae rmbekaemp fung
No 3:65-69, 1969
In 1966 the Institute for Building Technique
(ITS) in Warsaw conducted its first survey on
traffic noise in Warsaw. Later the cities of
Gdansk and Poznan were included.
As a result, uniform measurement and noise
maps and a catalogue with the acoustical
characteristics of various city planning
elements were prepared. These were later
used as a basis for aviation, city, traffic,
and railway noise measurement investigations.
Measurements were taken in;
1) Warsaw at 1500 measuring points and included
aviation, railway, truck and street car noise,
2) Gdansk at 500 measuring points (railways,
truck and street car noise),
3) Poznan at 100 measuring points (truck and
street car noise).
The heaviest traffic intensity was between
1-5 pen, with hardly any variations between the
time span, whether 20 or 240 minutes. During
that time the traffic noise level reached
above 90 dBA in the heart of Warsaw.
The surveys and noise maps have produced
valuable material for future projects and
further city planning.
Growing airport development and advancing
aircraft technology have not only resulted in
higher noise levels, but in public awareness
as well. As a result, ordinances regulating
aircraft noise have been passed. Noise
regulations are now in effect at London's
Heathrow Airport, and in New York. A critical
look at these ordinances is presented.
The State of California has proposed the most
complex regulations against aircraft noise
to date. The two-fold purpose of their
regulations is: 1) to bring about cooperation
between airport personnel and the community,
and 2) to impose penalties on aircraft
operators exceeding set noise limits. The
proposed regulations are based on perceived
acceptable noise limits of the communities
surrounding the airports and the economic
and technical feasibility of complying with
the standards. The regulations contain eight
separate airport classifications based on
traffic density and aircraft type. Maximum
single event noise exposure levels are
established for each type and measured as
the noise exposure level for a single event
with a duration of 10 seconds. Any aircraft
exceeding specified limits would be committing
a misdemeanor and the operator could be
subjected to a $1,000 fine. To maintain
these standards, elaborate noise monitoring
equipment will have to be used 24 hours a day.
The airport operator is responsible for the
monitoring and maintaining records, county
inspectors to review the records.
Economic questions arise. Typical installation
at Los Angeles International Airport will
initially cost $200,000 to $250,000 to
monitor 4 run/jays on a 24-hour basis at
30 points surrounding the airport. Installation,
operation and maintenance will cost about
$1,000,000 for the first year.
Older jet aircraft will have to be retrofitted
with noise attenuation kits to meet regulations.
It will not be feasible to enforce regulations
untiI then.
Although unduly complex and very costly, it
is felt that the proposed regulations wiI I
accomplish a much needed reducfion of noise
levels in and around U. S. airports.
08-001
Schneider, M.
California State Dept. of Public Health,
Los AngeIes
Bureau of Occupational Health & Environmental
Epidemiology
P. 0. Box 30327, Terminal Annex
A CRITICAL LOOK AT AN AIRPORT CONTROL ORDINANCE
American Industrial Hygiene Association Journal
Vol 32 No 7:480-487, 1971
08-002
THE FIRST TRUCK RESTRICTION ON FEDERAL
HIGHWAYS DURING NIGHTTIME
Erstes Lastkraftwagen Fahrverbot auf
Bundesstrassen fuer die Nachtzeit
Kampf dem Laerm
Vol 18 No 6:166, 1971
118
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LEGISLATION & STANDARDS
08-003
The first truck restriction on Federal highways
was passed in Hessen, Germany. The law passed
in Hessen pertains to Highway 354 between
Alsfeld and Homberg in North Hessen for
night-time between 10 P.M. and 6 A.M., and
restricts the passage of trucks over 4 tons.
Minister Karry explained that all attempts
must be made to restore peace at night to
citizens living near Federal highways. It
is unfortunate that the restriction does
not apply to other main routes in Hessen as
well. Consideration was given to the
citizens instead of to the freight industry
in this case because a parallel route was
available that could be used by trucks instead
of Highway 354.
08-003
Goldstein, S. N.
Mitre Corp., Mclean, VA
A PROTOTYPE STANDARD AND INDEX FOR
ENVIRONMENTAL NOISE QUALITY
At: The Eighty-Second Meeting of the Acoustical
Society of America, Denver, OCT 21, 1971
McLean, VA, Mitre Corp, 1971, 11p.
Author
A prototype technical standard for environmental
noise is proposed in terms enabling an index of
noise quality to be defined and calculated. The
standard takes into account the damaging
aspects of chronic exposure to loud noise as
well as psychologically disturbing aspects of
typical community noises which are not loud
enough to be physically dangerous. Inasmuch
as the standard is intended to portray
environmental quality rather than to reflect
damage risk criteria, it is generally
conservative with respect to work-related
noise standards, such as those specified by
the Walsh-Healey Act. The basic standard
specifies a distribution of noise intensities
to which an individual might be exposed in
a 24 hour period. The distribution may be
approximated by the composite of three
Gaussian distributions with means and
standards deviations of (30 and 3), (50 and
8.5), and (70 and 14) dBA. These component
distributions correspond to 8 hour periods
for sleep, miscellaneous daily activities, and
work, respectively. Alternative strategies for
obtaining data for calculating the related
noise quality indices are discussed.
08-004
Denisov E. I.
Institut Gigiyeny Truda i Profzabolevaniy
AMN SSSR, Moscow
NEW HEALTH NORMS ON NOISE
Novyye Sanitarniye Normy po Shumu
Gigiyena Truda i ProfessionaI'nyye Zabolevaniya
Vol 14 No 5:47, 1970
"Health norms and regulations on noise
abatement in areas and rooms of industrial
enterprises," No. 785-69, promulgated by the
Ministry of Health of the Soviet Union on April
30, 1969, was elaborated by the Laboratory for
Noise and Vibration of the Institute of
Labor Hygiene and Occupational Diseases. The
norms and regulations were based on in-house
documents and international recommendations.
The document establishes permissible noise
levels, conditions and specifications for
measuring it, basic measures for noise
abatement and for prevention of harmful
effects.
The norms regulate the maximum permissible
spectra of noise using the family of criteria
curves recommended by the TK-43 Committee on
Acoustics of the ISO. Rooms used for
intellectual work (offices, design bureaus,
etc.) have a maximum permissible noise limit
equivalent to about 50 dBA; rooms for office
work (typing pools, rooms with office
calculators, etc.), 60 dBA; control consoles
and observation rooms, 65 dBA; laboratories
with noise sources, 75 dBA; and work areas in
rooms and areas of industrial enterprises,
85 dBA. The norms allow for corrections for
duration of the noise during the work shift
and for the character of the noise (a correction
of 5 dB is allowed for tonal or impulse noise
measureable by a standard noise level meter).
The norms also indicate measures for technical
and medical prevention of adverse effects of
noise. They require periodic medical
observations of persons working under noise
conditions beyond the permissible levels
and give contraindications to employing persons
in noisy shops. These are based on domestic
research on the effects of noise not only on
the auditory organs, but on the organism as
a whole. The norms allow for elaboration of
departmental norms on noise, with subsequent
promulgation by the Ministry of Health of the
Soviet Union and by the State Construction
Agency of the Soviet Union (Gosstroy SSSR).
These are to be based on ergonomic requirements
and not solely on established maximum
permissible levels of noise.
119
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08-005
LEGISLATIONS STANDARDS
08-005
Lesser, J.
Port of New York Authority, NY
THE AIRCRAFT NOISE PROBLEM: FEDERAL
POWER BUT LOCAL LI ABI LITY—PART I
The Municipal Attorney
Vol 13 No 1:13-21, 1972
It is largely because of aircraft noise that
new desperately needed airports cannot be
developed and existing air terminals cannot
be expanded.
Since 1815, courts have been deciding questions
of who owns the air above property. The first
Supreme Court decision on aircraft noise came
in 1946, in the case of United States v. Causby.
The court found in favor of Causby, ruling that
the low aircraft altitudes caused trespass and
nuisance. The owner and operator of the
aircraft was held liable; the case did not
involve possible liability of the airport
operator.
In 1952 local government attempted its first
regulatory role in the field of air traffic
control. The Village of Cedarhurst, NY, near
Kennedy International Airport, enacted an
ordinance forbidding aircraft flyovers at less
than 1,000 feet altitude. The Airline
Association and Port of New York Authority
brought suit in Federal Court to enjoin
enforcement and were upheld. A similar
ruling was made in New Jersey in 1954.
Three 1958 Court of Claims decisions, all
on cases modeled after Causby, awarded
compensation for de facto taking of
easements. Since each suit dealt with
military aircraft, the government was held
liable as owner and operator.
08-006
Lesser, J.
Port of New York Authority, NY
THE AIRCRAFT NOISE PROBLEM: FEDERAL POWER
BUT LOCAL LIABILITY—PART II
The Municipal Attorney
Vol 13 No 2:30-39, 1972
The impact of the Supreme Court decision
rendered in the Griggs litigation against
the operators and users of the Greater
Pittsburgh Airport is discussed. This 1953
litigation was a test case. The Board of
Viewers awarded $12,690 to Griggs for the
condemnation of his property as of the day
in 1952 when "he Pittsburgh Greater Airport
opened.
Federal court:; have held that before a property
can be condemned aircraft must physically invade
the landowner's airspace. On the contrary, some
state courts have ruled that lateral flights
can constitute compensable takings within the
meaning of constitutional standards. The
burden of proof that property has been
constitutionally appropriated is in dispute,
as well as the statute of limitations.
The effect of the Griggs ruling was to direct
property owners to sue the airport operator
in an inverse condemnation action, thus
placing the f'nancial burden on the segment
of the aviation community least able to do
anything about it. In a recent inverse
condemnation action involving over 1,500
plaintiffs owning 750 separate residential
properties in the vicinity of Los Angeles
International Airport, total damages of
$750,000 were awarded. Similar awards have
been made in other states.
Local ordinances have generally been defeated,
but have prompted regulatory action by airport
authorities. Zoning laws by themselves have
not been much help in fighting aircraft noise,
because when they limit the use of property of
existing owners, they constitute a taking of
private property without compensation.
The 1968 Federal legislation on aircraft
noise requires the FAA not only to prescribe
standards for measuring noise, but also issue
rules for its control and abatement. In
1969 the FAA's standards for noise took effect.
Unfortunately, the noise standards were not
as strict as airport neighbors and airport
operators had hoped, since the FAA had previously
stated that noise levels of 106 EPNdB measured
at three statute miles from the start of
take-off roll, one statute mile from the landing
threshold, and 1,500 feet from fhe center line
of the runway were 'well within the state of
the art.1 Yet, the FAA's rule would permit
noise levels on very heavy future aircraft to
reach 108 EPNdB at measuring points farther
from the runway than originally proposed and
contains a "trade-off" provision which would
mean that noise levels as high as 110 EPNdB
would be permissible. Since the EPNdB scale
is constructed on logarithmic base, the
difference between 106 and 110 EPNdB alone
would reflect about a 50 percent increase
in annoyance. The "trade-off provision
would allow noisier take-offs and landings,
for instance, if they were compensated for
by a reduction in sidel ine noise. In addition,
the rule was further diluted by exempting the
initial group of approximately 160 Boeing
747's, the jumbo jets, from its coverage.
However, the FAA makes no claim that the rules
are acceptable or unacceptable for particular
a Irports.
120
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08-007
LEGISLATION & STANDARDS
08-007
Hurlburt, R. L.
Inglewood Department of Environmental
Standards, CA
105 East Queen St, Zip 90301
NOISE REDUCTION DESIGN SPECIFICATIONS FOR A
SOUNDPROOFING ORDINANCE FOR SINGLE AND
MULTIPLE FAMILY DWELLINGS
In: Inglewood's Community Review Program:
Final Report
Inglewood, CA, City of Inglewood, 1972
(p. 64-68)
The City of Inglewood proposed a special
residential sound proofing ordinance because
of Inglewood's particularly high exposure to
aircraft noise from Los Angeles International
Airport and aircraft operations associated
with it. However, the ordinance is not
applicable to communities generally or even
to those impacted by aircraft noise, without
further study of the particular local
conditions. These conditions include housing
practices in the area and the particular
aircraft noise environment.
The zones and design criteria envisage a two
stage reduction of noise levels inside single
and multiple family dwellings. They were
developed primarily from the results of
soundproofing programs in a localized area
around the airport. For the Inglewood area,
residential areas outside the 65 CNEL contour
need only normal housing construction to
provide an acceptable noise environment
i ndoors.
Areas in the 65-75 CNEL range require that the
building construction provide a reduction of
28 dBA, and those inside the 75 CNEL contour
need a 35 dBA reduction, which appears the
practical limit without detailed soundproofing
studies and designs in each new construction
at extreme increases in cost. Zones in the
soundproofing ordinance bounded by the 65 and
75 CNEL contours seem the best choice for
specifying two stages of soundproofing, with
the goal of providing uniform indoor noise
environments for all the dwellings in Inglewood.
These zones are to be selected not on present
CNEL contours, but rather on those estimated
for the year 1980.
New housing (and additions costing more than
$10,000) in the 65-75 CNEL contour interval
must provide at least 28 dBA noise reduction
with all external doors and windows closed,
according to the proposed ordinance, which
specifically requires certain construction
features. These features include an air
conditioning system, interior fiberglass
linings in air ducts, solid core external
doors, special workmanship on external doors
and windows, and well-fitting dampers on
chimneys. Prohibited outright are direct
openings to the outside such as mail slots.
Also prohibited are jalousie windows and
skylight constructions (unless the skylights
provide overall reduction of at least 28
dBA) .
Requirements within the 75 CNEL contour are
for a noise reduction of at least 35 dBA.
In addition to the specific construction
requirements needed for 28 dBA reduction
the following are mandatory: external
doors of sealed acoustical design with an
STC rating of at least 36 dB; sealed
acoustical double-glazed windows with an
STC rating of at least 39 dB; vents to the
outside having fiberglass lined baffle
boxes in addition to the normal grills.
The use of exposed beam ceilings is prohibited
unless special plywood and fiberglass acoustical
treatment is provided between the ceiling and
roof line. Details of this treatment, or its
equivalent, are specified.
The Building Director would have the power to
require changes in design plans that he deems
necessary to meet the 28 dBA and 35 dBA noise
reduction requirements, according to the
proposed ordinance. Details of field tests
are to be specified.
08-008
Cuadra, E.
Environmental Protection Agency, Washington, DC
Office of Noise Control & Abatement
1835 K St. NW, Zip 20036
A FRESH BREEZE IN STANDARDS WRITING
Sound and Vibration
Vol 5 No 11:24-27, 1971
Noise ratings for mass consumer oriented
products are complicated by the number of
requirements such ratings must satisfy:
1) rank-order the noisiness of various models
and brands of a products; 2) relate the
noisiness to sounds familiar to the consumer
so that he may easily interpret the rating
number; 3) provide repeatable measurements,
so that the manufacturer can be sure of
conformance, avoiding the possibility
that he will have to redesign; and
4) be simple enough to be approximated in
the home rather than the laboratory, for
purposes of preliminary screening by regulatory
officiaIs in the field.
121
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08-009
LEGISLATIONS STANDARDS
The office of Noise Abatement and Control
welcomes the cooperation of the various
professional societies in developing
measurement standards, because a combination
of voluntary action and regulation will mean
better progress in noise control than
regulation alone.
08-009
Sutton, P.
Esso Petroleum Co.
Fawley /England/
Esso Refinery, Fawley, Southampton,
England
NOISE AND THE COMMUNITY
Annals of Occupational Hygiene
Vol 14 No 2: 109-117, 1971
4) The corrected criterion, together with the
background noise, is compared with the corrected
noise level to determine the likelihood of
compI a i nts.
Generally, if the corrected noise level equals
the corrected criterion, complainfs are not
likely to occur. If it is 10 dBA higher than
the corrected criterion, complaints are likely.
The Standard only enables assessment of the
problem and the prediction of complaints; it
does not set criteria for acceptability or
limits. It seems to be a fairly reliable
guide, although one shortcoming is that the
measured nightime background noise level is
often significant I/ lower than the corrected
criterion. Actual background noise level can
vary from urban to rural areas and is greatly
affected by transient noises such as
intermittent traffic, dogs barking, and wind
noise. Besides these factors, wide variations
exist depending on local activity and noise
from distant sources.
Increasing attention is being paid to
neighborhood noise from industrial plants
and increasing costs are being incurred in
noise control. The first step in neighborhood
noise control is a realistic assessment of
noise as a nuisance or source of discontent.
The legal position in Great Britain is reviewed
and the problem of insufficient information on
public response to the relatively low level of
noise generated by industrial plants is
discussed.
The ideal is obviously that no one should be
disturbed, and the only way to do this is to
keep industrial noise totally from the
community. However, this is unreasonable, and
so perhaps the most common criterion is that
noise be kept as unobtrusive as possible
without causing widespread or persistent
comp I ai nts.
The British Standard BS4142 (British Standards
Institution, 1967) sets the following procedure
for predicting noise complaints:
1) A "corrected criterion' is calculated based
on factors such as the type of neighborhood,
the location of the plant in relation to the
neighborhood, and the time of day the noise
occurs.
2) A measurement is made of the background noise
alone (without the noise from the factory) if
possible.
3) The noise level from the factory is corrected
by factors such as noise character to determine
the ''corrected noise level."
08-010
Hansen, P.
Verein Deutscher Ingenieure, Duesseldorf
/West Germany/
Ruschenstrasse 20,
43 Essen-Bredency, West Germany
ACTIVITIES REPORT FOR 1971
Taetigkeitsbericht 1971
Duesseldorf, Verein Deutscher Ingenieure,
1971 , 33p.
The Annual Report for 1971 of the
Commission on Noise Abatement of the
German Engineer Association details
its activities in +he field of noise
abatement and control.
As of December 1971, membership in the
Commission amounted to 300 voluntary
workers. It is subdivided into sub-
commissions and groups concerned with
the following noise areas: 1) industrial
noise, 2) traffic noise, 3) residential
noise, 4) effects of noise,
5) application of measurement methods,
6) special problems, and 7) less
noisy construction.
The first colloquium of the Commission
was convened in 1971 and covered the
theme of 'Noise Reduction in Rail Traffic"
122
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08-011
LEGISLATIONS STANDARDS
The Commission on Industrial Noise met
twice with the Commission on the
"App I i cat ion of Measurement Methods"
and drafted a number of guidelines,
one of which became a DIN-norm. Many
of these guidelines resulted from
effort1*- of sub-groups working on the
various subjects of industrial noise
and some tasks were even undertaken
by pri vate f i rms.
The Commission on Traffic Noise wi^h the
cooperation of the sub-commission on ''Rail
Noise' held a colloquiurn entitled "Noise
Reduction in Rail Traffic" on FEB 9, 1971,
in Duesseldorf, with not only domestic
but also international participation.
In FEB, 1971 the sub-group on ''Rail Noise1'
drafted a guideline on Noise Measurements
in Rail Traffic, which will be printed as
a DIN-norm, after its revision.
The various other sub-commissions and groups
concerned with the aspects of traffic noise
were preoccupied with other research tasks
and the drafting of guidelines.
The Commission on "Residential noise" met
in OCT 28, 1971 in Duesseldorf. The main
purpose of this conference was the
discussion on the draft of the VDI 2719
guideline on "sound-damping of windows,"
produced by the sub-commission by the same
name. II was decided to reedit the draft
and a spring 1972 publication date was set.
Other sub-groups dealing with elevators,
heating systems, armatures and home
appliances, in general, have also dealt
with noise control and the establishment
of guidelines in these areas.
The Commission on Measurement Methods has
been busy with other sub-commissions on
guideline draft VDI 2058 "The Assessment
of Occupational Noise within the
Neighborhood'1. This commission also
convened study conferences, such as the
"Noise Reduction in the Bottling Industry"
conference held in Munich in OCT, 1971.
All manufacturers and operators of bottling
plants agreed to conduct measurements
and comp iIe all pert i nenf da+a in
order to coordinate plant measurement
tec.iroiogy ,/ith DIN 45635 'Noise
Measurements in Machines.'
The VDI-Commission on Noise Abatement made
plans to draft guidelines on the "Constructive
Measures Toward Noise Reduction - General
Principles" and "Constructive Measures Toward
Noise Reduction - General References".
The importance of this work was stressed
in a meeting in DEC and a "Sofort" (Priority)
plan was initiated for the drafting of those
guidelines. Part of the work is to be
finished by mid-MAY 1972.
In sum total the Commission has drafted over
18 guidelines, some of which have already
been pub Iished.
08-011
Caccavari , C.
Chicago Department of Environmental
Control, IL
Engineering Division, Dept. of Environmental
Control, 320 N. Clark St., Chicago, Zip 60610
A NEW COMPREHENSIVE CITY NOISE ORDINANCE
In: Crocker, M., Proceedings of the Purdue
Noise Control Conference, JUL 14-16, 1971
Lafayette, IN, Purdue Univ, 1972, 594p.,
(p. 263-268)
Chicago's quantitative noise ordinance, passed
in 1957, set a nationwide example, but increased
urban noise required design of a new ordinance
which, after a preliminary study and extensive
hearings, was passed in MAR 1971 and went
into effect in JUL 1971. The main source of
thrust of the new ordinance is directed at
motor vehicles. Sales and operational limits
are both used. By 1980 all vehicles
manufactured to be sold in Chicago must meet
a 75 dBA criterion at 50 feet from center line
of travel. By 1978 vehicles travelling at 35
mph or less in the City must emit no more than
78 dBA (motorcycles) and 70 dBA (cars),
respectively, at the 50 ft distance. Trucks
(= any motor vehicle with gross weight of
8000 Ib or more) travelling 35 mph or less
must emit no more than 86 dBA at 50 ft by
the beginning of 1973, including noise from
their auxilliary equipment.
In the month before the new ordinance went
into effect, vehicle measurement teams measured
about 200 motorists per week, both to develop
proper enforcement techniques and to provide
motorists with a courtesy warning. In the
first week of actual enforcement, 48 vehicles
were given citations, almost all of which were
trucks.
Restrictions on the sale or leasing of noisy
powered equipment or hand tools is given in
the followi ng table:
123
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08-012
LEGISLATIONS STANDARDS
Type of Equipment
Noise Limit
at 50 ft
(1) Construction and industrial
machinery—not including pile
drivers, manufactured after:
1 JAN 1972 94 dBA
1 JAN 1973 88 dBA
1 JAN 1975 86 dBA
1 JAN 1980 80 dBA
(2) Agricultural tractors and
equipment manufactured after:
1 JAN 1972 88 dBA
1 JAN 1975 86 dBA
1 JAN 1980 80 dBA
(3) Powered commercial equipment
of 20 HP or less intended for
infrequent use in a residential
area, such as chain saws, powered
hand tools, etc., manufactured
after:
1 JAN 1972 88 dBA
1 JAN 1973 84 dBA
1 JAN 1980 80 dBA
(4) Powered equipment intended for1
repetitive use in residential areas,
such as lawn mowers, small lawn and
garden tools, snow removal equipment,
manufactured after:
1 JAN 1972 74 dBA
1 JAN 1975 70 dBA
1 JAN 1978 65 dBA
Restrictions on the sale or leasing of
recreational vehicles are as follows:
Date of Manufacture after:
Noise Limit
at 50 ft
Snowmobi le
1 JAN 1971 86 dBA
1 JUN 1972 82 dBA
1 JUN 1974 73 dBA
Any other vehicle, including
dunebuggie, all-terrain vehicle,
go-cart, mini-bike
1 JAN 1971 86 dBA
1 JAN 1973 82 dBA
1 JAN 1975 73 dBA
A further restriction on the operation of
recreational vehicles is that they may not be
operated on property zoned for business or
residential use so as to create noise levels
exceeding 86 dBA at 50 ft. This limit
will be tightened to 82 dBA at the beginning
of 1973.
A restriction on the operation of motor boats
operating in the harbor of Chicago, or anywhere
on Lake Michigan within two miles of the city
limits, is that they may create noise levels
of no more than 85 dBA at 50 ft. This
Iimit will be tightened to 76 dBA at the
beginning of 1975.
Measurement of all the limits listed above are
to be made in accordance with ANSI, SAE, and
IEEE standards specified in the law.
Noise at the boundaries of construction sites
is not covered in the new ordinance because
it was felt that more technical data was needed.
Data needed to design noise limits on
construction sites is now being gathered.
Meanwhile, disturbing the peace statutes,
persuasion, and the limit on operating hours
are all being used to achieve some control over
construction site noise.
Noises emitted from buildings or equipment on
property is covered by the old ordinance, which
has been modified in the new ordinance in three
ways:
1. Introduction of the new preferred octave
band center frequencies.
2. Use of the "A" scale (use of dBA units)
for monitoring purposes.
3. Noise limits are now applied to the lot
lines of business, commercial, and residential
property, instead of to the zoning district
boundary lines as before.
08-012
Caccavari, C.
Chicago Department of Environmental
Control, IL
Engineering Division, Dept. of Environmental
Control, 320 N. Clark St., Chicago, Zip 60610
URBAN NOISE LEGISLATION
In: International Conference on Transportation
and the Environment, Part II
MAY 31-JUN 2, 1972
New York, Society of Automotive Engineers, 1972
The sources of noise in urban areas, existing
regulations in Chicago to control such noise,
and needs for additional legislation are
discussed.
Transportation noise is the major source of
noise in Chicago. Trucks operate in close
proximity to residential dwellings. Trucks
on inner city expressways, operating at night
at higher speeds that make tire noise a more
severe problem, create a very intrusive noise
124
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LEGISLATION & STANDARDS
08-012 (CONT.
problem because of lower background noise
levels at night. Specialized truck noise
problems occur when large numbers of
refrigerated vans stand at terminals with
motors left running, and when scavenger refuse
pickup trucks (engine noise plus noise from
the packer unit) and oil delivery trucks
(pump noise) operate at night.
In addition to trucks, automobiles and
motorcycles can be noise problems when the
exhaust muffler systems are defective or
modified. Automobile horns are another
problem, especially when used for prodding
traffic or alerting passengers waiting
to be picked up.
The older elevated system in Chicago is
a nuisance to the community 24 hours a day.
The subway system affects only its passengers,
but is a more severe problem in the summer
when train windows are open.
Railroad noise comes not only from pass-bys
on the right of way, but also from switchyards,
where diesels are run night and day. A new
noise problem is the loading of "piggy-back"
trucks onto raiI road cars in the rai I road yard
near residential areas—both the noise of the
diesel-driven loading equipment and the trucks
themselves, which are often refrigerated and
left standing with equipment running. Train
whistle intensity, which has been increased
to penetrate the newer sound proof cars, is
another problem.
Chicago has three regulatory instruments for
dealing with transportation noise: limits
on new equipment sold for use in Chicago
(Table 1), limits on use (Table 2), and
limits on noise levels at boundaries of
Zoning Districts.
Table 1 - Sale of new vehicles
Vehicle Type
1 )
Motorcycles
Same
Same
Same
Same
Date of
before
after 1
after 1
after 1
after 1
Manufacture
1 JAN 1970
JAN 1970
JAN 1973
JAN 1975
JAN 1980
Noise Limit
at 50 ft.
from center
1 i ne of
travel, dBA
92
88
86
84
75
2) Trucks (gross
weight of 8,000
Ibs. or more) after 1 JAN 1973 86
Same after 1 JAN 1975 84
Same after 1 JAN 1980 75
3) Passenger cars,
(and any other
motor vehicle) before 1 JAN 1973 86
Same after 1 JAN 1973 84
Same after 1 JAN 1975 80
Same after 1 JAN 1980 75
The manufacturer, distributor, importer, or
designated agent shall certify in writing to
the Commissioner that his vehicles sold within
City comply with the provisions of this section.
Table 2 - Maximum noise levels during operation
of motor vehicles under any condition of grade,
load, acceleration or deceleration.
Noise Limit at 50 ft.
distance in Relation
to Posted Speed Limit
Type of Vehicle
35 MPH or Less
(dBA)
Over 35 MPH
(dBA)
1) Trucks (gross
weight of 8,000
Ibs. or more)
before 1 JAN 1973 88
after 1 JAN 1973 86
2) Motorcycles
before 1 JAN 1978 82
after 1 JAN 1978 78
3) Passenger cars
(and any other motor
veh icle)
after 1 JAN 1970 76
after 1 JAN 1978 70
90
82
82
79
This section applies to the total noise from
a vehicle or combination of vehicles.
As Tables 1 and 2 show, lower limits will be
required in the future. One automobile
manufacturer removed six car models from the
Chicago market because they did not meet
Chicago's law. Three of these models were
reinstated after exhaust systems were
redes i gned.
The problem of several trucks with refrigeration
units running simultaneously on a factory
property can not be handled with the motor
vehicles codes, because the individual units
can all meet the noise limits. However, in
these cases the property line noise limits
can be used to regulate the nuisance.
In Chicago's enforcement program, most of the
citations were given to trucks (nearly 50?)
followed by cars and motorcycles. In addition,
1800 complaints were responded to, not all of
which proved to be violations. Most frequently
complained about were air conditioners,
construction noise, scavenger trucks, other
trucks, factory noises and musical instruments.
Even when there was no violation, the Department
of Environmental Control made suggestions for
quieter operation, such as moving the air
conditioner to another location. In a case
involving residential complaints about
'piggy-back'1 unloading in a railroad yard,
a violation of the district zoning noise
125
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09-001
ENFORCEMENT
restriction was found. Action was taken
inducing the railroad to undertake a major
noise reduction program, including removal
of refrigeration units to a different yard
and design of sound absorbant enclosures for
the diesel engine and mechanized arms of the
unloader. The program will gradually reduce
noise from the railroad yards to the legal
limit of 55 dBA at the residential/manufacturing
zone boundary Ii ne.
Excessive hornblowing has been controlled using
the provision of the ordinance prohibiting use
of any audible device on a moving vehicle
unless it is an emergency, and no use whatsoever
while the vehicle is standing. This provision
is also used to restrict excessive noise from
ice cream trucks.
A drawback to the present limits on sales of
new vehicles is that the manufacturer may be
faced with a multiplicity of local and state
requirements. Uniform federal regulation of
noise from new equipment would ideally solve
this problem, and still give local governments
the option of setting more stringent use
requ i rements.
Local restrictions would be need€;d even if
Federal restrictions on noise sources were
set. One example is trucks accelerating
from a stop sign in a residential area.
Another example is the grouping of trucks
with refrigeration units, although the
individual trucks could meet Federal limits.
Finally, construction equipment could meet
Federal standards individually but when
operating all at once on a construction
site, create a community noise problem that
should be regulated locally.
Another problem is that it is financially
impossible for cities like Chicago, New York,
and Boston to replace existing mass transit
systems with something quieter. Controlling
this noise source will be a slower process,
with the gradual purchase of quieter equipment
and installation of smoother rails. Cities
buiIding new systems should not repeat the
mistakes made by those with existing systems.
A problem in enforcing against railroad noise
is that noisy rolling stock is owned by dozens
of different lines, and the local yard has
little control over what comes in. This is a
suitable area for Federal action.
Proposed Department of Transportation standards
for noise from new expressways—recently revised
to 70 dBA at the property line—will be only
marginally useful in protecting adjacent
residential communities because the 70 dBA
number is too high. Noise problems around
existing airports occur because buildup of
residential communities close to traffic
patterns has been allowed. With present
knowledge of airport noise, it should be
possible to avoid similar problems in the
future through land use planning. Information
of the design guide type, supplied by several
Federal agencies, can be useful only if it is
incorporated into the development and growth
of our urban areas. The EPA should provide
both technical and financial assistance to
state and local agencies.
09-001
Schenker-Spruengli, 0.
Schweizerische Liga Gegen den Laerm
Zurich /Switzerland/
PROGRESS OF NOISE ABATEMENT IN SWITZERLAND
Fortschritte der Laermbekaempfung in der
Schwei z
Laermbekaempfung
No 3:27-28, 1969
Since 1957 Switzerland has established a
Federal Expert Commission for Noise Abatement.
It consists of 52 experts and is divided into
5 sub-commissions dealing with the following
probI ems:
1) Medical, acoustical and technical
principles,
2) Motor vehicles, Railroads, Ships and Cable
cars,
3) Aviation noise,
4) Construction and industry noise, Sound
protection in buildings, etc.,
5) Legal problems.
It has accomplished considerable progress with
the cooperation of the Swiss League Against
Noise. The biggest enlightment action resulted
in 1962 through the conference of city police
directors in which 150 communities participated.
In 1963 a special instructional course in Noise
Abatement and Control for law enforcement groups
was conducted in Zurich. The League also
conducted 4 big scientific conferences, 6
technical exhibits and numerous demonstrations
concerning the practical and technical aspects
of noise abatement.
One big progress is the establishment of the
recommended noise levels. The noise levels
are measured on a dBA scale according the CEI
publication #123 taken in an open window.
Background
Noise
Night Day
35 45
45 55
45 60
50 60
55 65
60 70
Frequent
3eaks
Night Day
45 50
55 65
55 70
60 70
60 75
70 80
Occas iona I
Peaks
Night Day
55 55
65 70
65 75
65 75
70 80
80 90
Zone
A
B
C
D
E
F
126
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09-002
ENFORCEMENT
A - Recreational areas
B - Quiet residential areas
C - Mixed areas
D - Commercial areas
E - IndustriaI areas
F - Main traffic artery
Desirable Values: about 10 dB less, however
not below 30 dBA
Background noise: mean value (average level,
w i thout peaks)
Frequent Peaks: 7-60 sound peaks per hour
Low Peaks: 1-6 sound peaks per hour
Also many other reasons and ordinances were
instituted, for instance: the health insurance
was revised to incorporate hearing loss as an
insured occupational illness; the establishment
of Noise Abatement Commission in various cantons
and cities; and Noise Abatement offices
supervised by the police in many cities, as
Basel, Bern, Lausanne, Luzern, Lugano and Zurich.
Zurich's office is an exemplary and most
active one.
The biggest battle is civil supersonic
overflight. Much has been done, although
much still remains to be accomplished.
09-002
Smith, W. A.
University of South Florida, Tampa
NOISE CONTROL LEGISLATION IN FLORIDA
At: Noise Control Workshop, Harriman, NY, JAN
18, 1972
Tampa, University of South Florida, 1972, 4p.
Activities of the Florida Legislature in the
area of noise control are discussed. The
State Environmental Protection Agency has been
given authority to set standards. The State's
particular interest is vehicular noise and it
wi I I set up noise test equipment at its Motor
Vehicle Inspection stations.
State and local governments are interested in
control Iing noi se, but are not yet willing to
fund it. There are no noise control experts
on the State EPA staff.
Most local ordinances are "do not disturb the
peace'1 variety except for a few which set
noise limits. For instance, a cement plant
was forced to close when it could or would not
bring its noise down to acceptable levels.
A survey was made by acoustics students of the
University of South Florida to test the effect
the new proposed standards, such as the Chicago
Ordinance, would have on the noise level. The
results showed a small percentage of violators.
Among those found, the worst offenders were
trucks and motorcycles.
Florida hopes that the new national noise
standard for vehicles will be set considerably
lower than those of the present Chicago
Ordinance and that the enforcement wi I I become
part of the annual motor vehicle inspection
p rogram.
09-003
Warren, D. G.
North Carolina Univ., Chapel Hill
Institute of Government, Chapel Hill, NC
THE PROBLEM OF NOISE: HAS ANYONE HEARD AN
ANSWER?
Popular Government
Vol 38 No 2:16-19, 1971
A discussion of noise pollution and laws,
ordinances and legal actions which involve
noise is presented.
Noise is generally defined as unwanted sound.
Too much exposure to it obviously induces
hearing loss, along with heart disease,
migraines, intestinal disorders and some
allergies. It also interferes with
conversation, hinders concentration and
disturbs sleep.
A study of the Maban tribe in Africa revealed
that its noise-free society left 70 year old
men with hearing as acute as the average 20
year old New Yorker. An estimated 5,000,000
American males from ages 10 to 59 have some
degree of hearing loss, and 1,000,000 need
hearing aids.
A number of legal tools against noise are
avai lable and have been put into effect in
some areas of the U.S. The private nuisance
action, for instance, has been used to a
small degree in North Carolina. This is a
civil tort, and to be used, the interference
must be both a substantial and a legal cause
of the harm involved. Public nuisance affects
the public as a whole. Anything acted upon
under this action must interfere with public
health, safety and peace. The nuisance
ordinances now in effect are very vague. There
is no clear guideline as to what really creates
a nuisance. Furthermore, citizens themselves,
may be unwilling to go through the trouble
and expense of court action.
127
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09-004
ENFORCEMENT
In North Carolina, a farmer complained that
aircraft take-offs and landings in the space
directly above his chicken farm were an
unconstitutional taking of his property
(U.S. v. Causby). He was awarded damages
under the inverse condemnation principle,
which has been applied only against aircraft.
Antinoise laws must be aimed at preventing or
controlling noise. Most of the traditional
laws are zoning, antinoise ordinances, and
muffler controls; some of the new measures
are called decibel ordinances.
If used properly, zoning can be a great aid
in noise abatement and control. It can
separate industry and busy highways from
residential areas, for example. In order
to be effective, however, it must be used
in conjunction with other planning efforts.
California, Connecticut and New York have all
enacted decibel ordinances with maximum
noise levels which traffic noise must not
exceed. Although difficult to enforce, traffic
noise has been reduced.
The answer to noise control lies in the
cooperation of industry, government, city
planners and individual citizens.
produced by the City Police, entitled "Noise1,
was shown in various neighborhood movie-houses
and in schools throughout the week.
The whole teaching community was requested to
dedicate at least 2 hours of their teaching
program on the environmental topic. For
this purpose, a document was distributed
to the teachers. One section of the document
entitled, "Will we, should we, destroy ourselves
by Noise'1 was prepared by the Noise Abatement
Office.
The tasks and methods of the Noise Abatement
Office were investigated by BBC of London and
Norwegian TV. Officials from London, Washington
and other parts of Switzerland also visited
the of f i ce.
The following statistics show actions of the
Noise Abatement Office recorded by noise
sources:
Noise Source
1970
1971
1. Traffic Noise (Various
types of Motor Vehicles)
2. Construction
3. Commercial Noise (incl.
restaurants & private
clubs)
642 1,016
863 898
433
502
09-004
Birchler, F.
City Pol ice
Zurich /Switzerland/
ANNUAL REPORT 1971 OF THE NOISE ABATEMENT
OFFICE
Jahresbericht 1971 der Laermbekaempfungsstelle
Zurich, City Police, JAN 4, 1972, 3p.
4. Other Noise Sources
(household, neighbors,
animals, churcnes,
schools, etc.)
527 583
2,465" 2,999"
Out of 618 vehicles cited for noise violations
in 1971, 27 we^e condemned; 125 inquiries
concerning noi<;e abatement measures were
answered by mai I; 1402 interviews were granted;
16 frequency analyses were plotted; and 3037
inquiries were processed by phone. Only 8
of 2465 recorded actions could not be completely
resolved.
Activities and actions of the Noise Abatement
Office of Zurich during 1971 are outlined in
the Office's Annual Report.
The Noise Protection Law of 1971 was
promulgated by decree of the Zurich Municipal
Council. The law was reviewed by the
Cantonal Health Office and put into effect on
SEPT 1, 1971. This law has been quite
effective and successful in the enforcement
of the prescribed noise measures during the
4 months since its promulgation.
The 'Zurich Environmental Protection Week'
took place between MAY 3-8, 1971. The
program was arranged by the Acoustics Department
of the Health Inspection Office and the Noise
Abatement Office of the City Pol ice. A film
Kvitka, V.
NOISE FROM THE SKY
Science and Engineering Newsletter of Novosti
Press Agency
No 11(525):1-4
Current approaches toward solving the problem
of aircraft noise in the USSR include
introduction of a new generation of aircraft
128
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10-002
PROGRAM PLANNING
with high bypass ratio engines, restrictions
on building near airports, and flight
operating techniques for noise reduction.
The noise during take-off from IL-62 and TU-154
airliners, which have bypass turbojet engines,
\i. ,-12 dB lower than that of the older
generation of Soviet commercial jets. In
order to reduce noise of the exhaust jet on
new planes a special noise-reducing nozzle
operates only during take-off and, consequently,
docs no1 affe':V the flight performance of
the plane.
At present both construction of new airports and
expansion of old airports is regulated for the
purposes of noise abatement. Town building
near airports is restricted. However, new
regulations are being prepared by the USSR
Ministry of Health and USSR Ministry of Civil
Aviation. These are presently in the form of
recommendations on the zoning to provide
rational planning near airports. But they
are being submitted for approval as normative
standards i.e. standards given the force of
I aw.
Changes in piloting methods have yielded a
reduction of 5-8 dB, measured under take-off
paths, and of 7-16 dB during flight over
communities by means of thrust reduction.
Although there is a substantial increase of
noi?e at the airport during the take-off
ru<^ of SST's, due to the high thrust of the
engines, this same high thrust enables the
SSI to climb steeply. Thus, there will be
rather low noise levels at the second ICAO
take-off gauging point, which is located
about 600 meters from the start of rol I .
Furthermore, the Soviet SST engines are
to be fitted with devices for supply of
secondary air flow into the exhaust jet,
\ielding a 5 dB noise reduction during
take-off.
The prediction of 50 to 75? reduction is based
on the following factors:
1) The FAA regulation requires new generation
aircraft to be approximately half as loud
(10 EPNdB quieter) than present generation
aircraft. The 747 is covered by the new
regulation and meets its requirements,
but it will take 15 to 20 years before most of
the present noisy generation of aircraft
has been phased out.
2) In the shorter time frame of 5 years,
there is hope for a reduction if a retrofit
program is carried out on existing aircraft.
3) With community pressure and perhaps
some technological breakthroughs, it may
be possible to achieve a 20 EPNdB reduction
within 20 years.
Criteria for residential development near
an airport with a large number of flights are:
If the noise level exceeds 100 EPNdB,
development would not be satisfactory; if the
noise level is in the 90-100 EPNdB range,
development is marginal, and should only be
undertaken with strict sound proofing
requirements in the initial building design.
10-003
Man, A.
Israeli Medical Corps
NOISE POLLUTION
In: Marinov, U., The Environment in Israel,
Israel National Committee on Biosphere and
Envi ronment
Inglewood Department of Environmental Standards,
CA
STATUS OF AIRCRAFT NOISE POLLUTION
Inglewood, CA, City of Inglewood, FEB 1971, 2p.
The FAA measures aircraft noises in terms of
effective perceived noise decibles (EPNdB).
Ninety EPNdB would be termed noisy, 100 EPNdB,
very noisy; and 110 EPNdB, extremely noisy.
Each increase of 10 EPNdB would be judged to
sound approximately 'twice as loud." Present
noise levels near the airport due to jer
aircraft range from 90 to 120 EPNdB.
Jerusalem, 1971, 60 p. (p. 27-29)
A brief account is given of particular
noise sources, anti-noise laws, and noise
control organizations in Israel.
Because of the country's mild climate, the
population is outdoors-oriented, and spends most
time inside with windows open. Environmental
noise thus leads to psychoacoustic irritation,
although not usually to a loss of hearing.
Major sources of noise are buses and
motorcycles, workshops in residential areas,
and industrial plants, and loud discotheques
and other places of entertainment. The
textile, cement, and metal industries are the
noisiest in Israel, and produce sound levels
above the criteria considered harmful to the
ears. Aircraft noise is becoming an
increasingly serious problem. Agricultural
machinery is also beginning to create noise
problems. In addition, almost every young
129
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10-004
PROGRAM PLANNING
man and many young women have been exposed to
shooting or explosions during military service
and later in the reserve service.
A non-specific anti-noise law, the Kanowitz
Law, now in existence is being amended and
standardized. By-laws have also been passed
in regard to industrial noise and directives
have been issued concerning hearing-loss
compensation.
Governmental institutions which deal with noise
problems include: the Unit for the Prevention
of Air Pollution and Radiation Hazards of the
Ministry of Health; the Unit for Prevention of
Noise Hazards of the Israeli Medical Corps;
the Ministry of Labour; the Institute of
Standards; and a governmental committee assigned
to ammend the Kanowitz Law. Academic
institutions include the Acoustic Department of
the Technion in Haifa and the Department of
Electronics at the Weizmann Institute in
Rehovot. There are also a number of private
organizations serving as advisers on noise
problems to various industries and construction
companies.
10-004
EPA ANALYSIS OF NOISE PROBLEMS POINTS WAY TO
FUTURE LEGISLATION
Automotive Engineering
Vol 80 No 4:28-35, 1972
A discussion of the Report to the President
and Congress on Noise by the Environmental
Protection Agency is reviewed. The Report
presents a summary of the present noise problem
and status of legislation, and the solutions
and directions that engineers and legislators
will probably be taking over the next 15 years.
Aircraft noise, followed by highway noise,
has received the greatest Federal attention in
transportation noise abatement. At present,
Federal regulations are still in the development
stage for retrofitting aircraft for noise
control, controlling sonic boom, and
certifying SST and STOL/VTOL-type aircraft.
The EPA survey reveals that many states
have enacted noise control legislation—
nine states in the first six months of
1971 alone. Laws are incorporating specific
decibel limits. Florida, New York, Illinois,
Hawaii, and North Dakota now have departments
with the authority to set noise standards.
California regulations require the airport
operator to monitor take-off and landing noise
and to set a noise impact boundary around the
ai rport.
Five states have set limits on total vehicle
noise based on subjective standards. Five
states require mufflers on motorcycles.
California, Colorado, and Minnesota have set
overall limits on these vehicles that become
tougher with time. Five states currently
require mufflers on boats. Snowmobiles are
receiving more attention, with Maine and
Wisconsin requiring mufflers and Montana,
New York, Colorado, and Massachusetts setting
limits on new snowmobiles (the latter two
states also regulate snowmobile operating
noise).
The noise recuctions obtained with new
aircraft largely stem from improvements in
engine bypass ratios, fan designs, and new
designs for inlet and discharge ducts.
However, because of the large numbers of
older aircraft in use, most aircraft now in
use exceed the Federal Avioation Regulation
limits for new aircraft.
The noise produced by highway vehicles stems
from three major causes: tires and aearing,
the engine and related accessories, and
aerodynamic and body noise. Despite their
larger engines and tires, newer vehicles are
auieter than older vehicles. Diesel powered
trucks are 8-10 dB noisier than gasoline-
powered trucks, and 12-18$ noisier than
automobiles. One engine manufacturer estimates
a $1,500 increase in the $5,000 base price of
a 250-hp diesel engine to drop noise 10 dBA.
Recreational vehicles—motorcycles, snowmobiles,
all terrain vehicles and pleasure boats often
reach levels of 92 dBA. Typical noise levels
contributed bv the various subsystems in a
motorcycle range from 59-69 dBA at 20 mph
to 78-86 dBA at 60 mph. Most motorcycle noise
reductions have been achieved by exhaust
system changes. Snowmobile noise stems
primarily frori poorly muffled exhaust systems.
Current models generally are in the 77-86 dBA
noise band. EBoth inboard-and outboard
powered pleasure boats range from 65-105 dBA at
50 ft, with exhaust systems being the major
noise contributor.
Typical noise levels measured 50 ft from
construction equipment range from 72-96 dBA for
earthmoving equipment from 75-88 dBA for
materials handling equipment, and from 70-87 dBA
for stationary equipment. In almost all of
this equipmen"1", the e.ig'ne is the primary
source of noise.
EPA concludes that for engine-powered equipment,
the qreatest noise reduction may be obtained
by quieting the engines.
130
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10-005
PROGRAM PLANNING
10-005
Munich /West Germany/
MUNICIPAL-POLITICAL ASPECTS OF
ENVIRONMENTAL PROTECTION IN
MUNICH
Kommunal Politische Aspekte des
UmweItschutzes in Muenchen
Arbei tsberi cht zur Fortschrei bung
des Stadtentwicklungsplanes Nr 3
Munich, 1971, 163p.
Since JAN 4, 1971 Munich's council group
presented six proposals with 40 individual
points for an effective Environmental
Protection Plan for the city. A greater
publicity program, improvement of
measurement systems, restrictions on
individual traffic, introduction of
exhaust-free vehicles, restriction of
certain refuse, better supervision of
water and vegetation resources and a
catalogue with special preventive
measures are beinc planned. Proposals
are established en the basis of studies
of these measures.
A general inquiry and survey of all the
big cities in the German Federated
Republic helped to set up this working
group and establish these plans.
According to the proposal #255 (der
Gesamtdeutschen Partei) of JAN 9, I97I,
the following is planned:
I) A network throughout the city with
separate detectors for automatic
measurement of traffic flow and air and
noi se polIution.
2) Constant observations of the influence
of traffic on health, independent o*
weather, season and time (daily) factors.
Special noise measures are proposed to
include: strict rupervision of all
construction work, consultation with
builders, and investigation of new
construct ion.
Improvement of traffic flow on national
and state highways and main arteries of
the city and construction of park and
greenbelts and other means of traffic
directions are anticipated.
A street directory of the city district
is planned with the description of its
present situation, excluding the
strictly residential areas.
The Office or Economy Is responsible
for the measurement of landing and
take-off noise at the Munich airport.
For noise-reduction purposes the city
council recommends the following
measures:
1) No flight paths over the city
(especially supersonic).
2) No over city flights by old
ai rplanes.
3) Restriction on the number of
helicopter observation flights.
An inquiry was conducted which
showed that 63? of residents of heavily
populated areas complained about noise.
A noise level ranging from 30 - 90 Phon
can cause insomnia, disturb rest resulting
in a reduced concentration span,
decreased productivity, irritability and
nausea, affect the vege+ative nervous
system, cause gastritis and colitis,
increase metabolism, lessen proper
circulation and also cause
arteriosclerotic changes, as well as
psychic illness. Levels above 90 Phon
cause physiological damages such as
hearing loss or other hearing problems.
According to the proposed prognosis the
vehicular traffic will increase about
55? by I985. This means an increase of
1 - 2 dBA, and because the speed will
increase, 4 dBA will be added.
Physiologically this means that the noise-
level of street-traffic will increase
about 50?. In addition, a 70? increase
in large aircraft in civil flights can be
expected.
Special emphasis is put on public-
opinion and media, such as the press,
television and radio to inform the
general public and arouse greater
interest.
Munich teachers and scientists are
asked to form workshops to introduce
interdisciplinary courses in the field
of environment. Presently only the
biological aspects are encompassed
in the environmeital curriculum.
A commission selects short films
about various themes of environmental
protection. These films are offered
weekly to the local theater.
Amusement taxes serve to finance these
films. A 4% budget increase in social
products is suggested.
'n order to have greater enforcement
of the existing laws, increased
fines and other penalties
(especially in respect to water-
pollutants) are recommended.
Enforcement measures and
further research is encouraged concerning
restrict, ions on city overflights,
stricter supervision over construction
noise, improvement of damping materials
131
-------
10-006
PROGRAM PLANNING
and devices and other preventative
measures like greenbelts, earthbanks,
divj sunken highways for Traffic.
In this respect, recommendafions for
public transportation are proposed.
In order Tc set all the proposals
int action, formation of project
groups is necessary. Presently there
are 11 of then dealing with various
arpeci; of environmental protection.
Schwe izeri sche Liga Gegen den Laerm,
Zi-ricn /'Sv. i rzerl and/
PPCGREfj OF NO ISC ABATEMENT IN SWITZEPLAN
rorfschri tte der Laermbekaempfung in der
Schwe i z
The present major program is the national
campaign against civil supersonic jefs.
10-007
Kraege, R.
Institut fuer Schall- una Schwingungsfechnik,
Hamburg /West Germany/
2000 Hamburg 70, Fehmarnstrasse 12, West
Germany
NOISE MEASUREMENT CONDUCTED BY THE PARCEL
POST OFFICE IN HAMBURG
Laermmessungen bei der Paketpost in
Hamburg
Kampf dem Laerm
Vol 19 No 1:6, 1972
After the Noise Abatement '_eague of Switzerland
w=is formed and achieved considerable progress
in its efforts, the government came to its
support and endorsed in October 1957 the Federal
Exoc-f ? '-"Trillion for Noise Abatement. This
commission for Noise Aba+enenf, cornposec of
52 ^xperls from +he various seicnlific fields,
war- O'vced info 5 sub-comrru ssions :
1) medical, acoustical and technical principles;
?} motor xeb'oles, rai Iways and ^hips;
3) aviation no I so;
4) construction and industrial noise, sound
protection in residences, etc.;
5> ;u'Hi'iid! o rob] ems.
After five years of study a comprehensive
report was published in 1962.
ln^ League has conducted education programs
i
-------
10-008
PROGRAM PLANNING
10-008
Munich /West Germany/
On: LOCAL POLITICAL ASPECTS OF ENVIRONMENTAL
PROTECTION IN MUNICH
KommunaIpolitische Aspekte des UmweItschutzes
in Muenchen
Arbe itsbericht zur Fortschrei bung des
StadtentwicklungspIanes Mr. 3
Munich, 1971, 163p. (p. 55, 68-70)
As to industrial noise, a federal law is
planned to enforce noise reduction techniques
in all kinds of machinery and equipment.
In spite of increased costs, measures should
be taken to continue and improve building
techniques. Careful planning of residences
and other structures is also recommended.
A draft paper discusses proposals for
prospective noise laws for the city of Munich
in light of draft norms for the Federal
Republic of Germany.
No noise-measures have been established as yet
in Munich. Single noise sources are
investigated solely when there is a complaint.
So far only a system for aviation noise-
measurements has been set up.
Presently the Federal German Republic is
compiling general norms. The draft encompasses
the following noise levels:
Area
Strictly Industrial areas
Predominantly industrial area
M i xe d a rea
General residential areas
Strictly residential area
Day
(dBA)
70
65
60
55
50
Night
(dBA)
70
50
45
40
35
The law against aviation noise would contain
two noise-projection zones.
Zone I - noise exposure over 75 dBA
Zone I I - noise exposure over 67 dBA
Traffic noise ordinance would limit noise
levels as folIows:
Passenger car - max 84 dBA
Trucks - max 89 dBA
Motorcycles - max 84 dBA
AI I measurements are taken at a 7 meter
di stance.
During night hours (between 10 pm through 6 am)
all trucks would be restricted in most areas
with the exception of the city's main arteries
and purely industrial areas. (Proposals No.
255/6DP #3A, No. Z85/6PP #2).
Since APR 1, 1971 flight take-offs are limited
between 8 pm to 6 am, with the exception of
mail and freight carriers (No. 255/6DP #1).
Overflights of cities for purposes of
advertisement or observation are considered
unnecessary and should be eliminated. (No.
285 GDP #3).
10-009
Brown, L.
THE PERMITTED NOISE LEVELS FOR HEAVY VEHICLES
ON OPEN ROADS ALREADY EXCEED THE NOISE LEVELS
FOR JETS AT HEATHROW
Municipal Review
Vol 42 No 493:149-150, 1971
A retrospective study covering two years of
admissions to a psychiatric hospital shows
that there is a significantly higher rate of
admission, especially in certain diagnostic
categories, from inside an area of maximum
noise arising from the Heathrow Airport than
from outside this area.
Such information has lead to greater concern
over noise in Great Britain. The realization,
based on scientific research, has hit that
noise is not just an irritant, but is
definitely a mental and physical health hazard.
Some noises are accepted as a part of everyday
life, while there are others that we simply
get used to. But in our rapidly advancing
technological society, noise levels are
advancing also, and there is no getting used
to them.
The Noise Abatement Society (NAS) was formed
in Great Britain in 1959. An independent and
non-political pressure group, it receives no
financial or other help from the government.
Both corporate and individual memberships are
included, and over 600 local authorities are
members.
The society encourages authorities to pass by-
laws of noise levels and makes efforts to
persuade industry to develop quiet equipment.
In another activity, the Society last year
aided London in holding a "Quiet Week" and an
exhibition of silencing equipment.
In its troubleshooting capacity, the NAS will
aid any authority that considers noise a major
environmental problem. The officers know the
official procedures and the correct channels
through which to go for a solution to the
probI em.
133
-------
10-010
PROGRAM PLANNING
Mr. Geoffrey Holmes, Technical Adviser to the
NAS and Chief Public Health Inspector, Royal
Borough of New Windsor, has very definite views
of the problem of noise control and abatement.
He estimates that at least 10% of his work is
concerned directly with problems of noise and
the community.
For instance he relates the problem of traffic
noise to its routing, such as the time when the
opening of a new bridge caused traffic to go
straight into the town of Windsor. The Public
Health Department had just completed a survey
which showed tht 35)5 of the midday traffic
consisted of heavy lorries. Noise levels rose
more than 10 dB over those laid down by the
Wilson Committee. In fact, the permitted noise
levels for heavy vehicles already exceed those
for night jet flights at Heathrow Airport.
In addition a "canyon effect" produced by
traffic in narrow streets could raise the noise
level 6 dB greater, exceeding the daytime
aircraft noise limits. Mr. Holmes' solution to
traffic noise is to confine lorries to specified
routes.
Taking action on a traffic noise problem, Mr.
Holmes was confronted with the situation in
which a residential road was being used by
heavy traffic as a short-cut to the docks. By
merely writing to the companies whose lorries
were using the route and explaining the
discomfort they caused the neighborhood, Mr.
Holmes won his case. The firms cooperated by
re-routing thetr lorries.
He took a similar stance with regard to
aircraft noise at Windsor. The noise is worst
during the three months of the year when,
because of strong winds, aircraft must come in
and go out oy way of the borough. The problem
is that if minimum noise routes are not followed
the noise can be quite loud.
Convinced that some aircraft were not following
minimum noise routes, Mr. Holmes sent a report
of his suspicions to "the Board of Trade. As
a result, two major airl ines were found to be
ignoring the routes. Since then, the situation
has been much improved. At present noise
committee meetings being held at the Board of
Trade have representatives from the airlines but
not from the local authorities.
Looking at America there is apparently a lack of
governmental concern. Boeing is so concerned
that it has made a mathematical model for
evaluation of the various means of reducing
aviation noise. Tests have shown that any
technological changes will be complicated and
expensive, and in Mr. Holmes' view, the only
solution is to keep people and aircraft apart
by proper airport planning.
The NAS, together with other concerned
organizations, has agreed that the third London
Airport should be located at Foulness. If
situated inland, they conclude, it would
sterilize and spoil a large area of countryside.
Besides inland siting would create dangerous
probI ems in air traffic controI .
Airport expansion is not London's problem
exclusively; it is the concern of municipal
airports as well. Mr. Holmes says, one
wonders if sufficient regard is being paid to
the people and districts surrounding these
airports. Airport noise is more of a problem
than traffic noise. The big jet is very
annoying because of the high frequency element
in the noise. At least if heavy noise was
confined to certain routes the noise would be
localized, but no such remedy can be taken with
a i rcraft."
10-010
Schuler, K.
Kamekestrasse 37-39
Cologne /West Germany/
NOISE REDUCTION IN PUBLIC PASSENGER
TRANSPORTATION, ROLLING STOCK AND
INSTALLATIONS
Laermmi nderuncj bei Betriebsmi tte I n und—
anlagen des oeffentIichen Personennah -
verkeh rs
Kampf dem Laerm
Vol 18 No 5:157-130, 1971
The German Feceral Traffic Minister Leber,
while speaking at a session on subway and
motor vehicle construction, made an appeal to
employ all possible means for noise reduction.
The manufacturers and the public transit
concerns have tested various noise reducing
measures, such as sound-damping materials and
construction techniques.
Experiments were held in 10 plants on 30
railed vehicles, street-cars and subway cars.
Polishing of the tracks results in the most
noise level reduction, but spraying the tracks
with water and sand not only quiets the ride,
but also assures a much safer braking power.
It was observed that heavy snow is an excellent
noise-reducing agent. It is suggested that a
similar artificial type of covering would be
an excel lent abatement measure.
Chemical processes are being applied to abate
the "multitonal whines" of overhead tracks in
the interim before they are totally replaced.
In addition, 70 to 100 cm high sound protection
walls are being constructed as noise reducing
devices. One chemical abatement method, curve
lubrication, has proved ineffective.
The investigat'on of the tunnel construction in
Munich, where "he tunnel is deeper and the
134
-------
DATA
11-001
vehicles wider, disclosed that the thicker
tunnel walls contributed considerably toward
noise reduction.
Use of trolley-cars (0-Bus) declined in 1971
in favor of the more economical Diesel-bus,
which is too loud because of its motor and
tires. The Electro-bus (E-Bus), a totally
electrical bus, made its appearance recently;
it is economically less feasible than the 0-bus.
Since fiscal considerations dictate the present
Diesel-Bus, casing and damping measures to
solve at least the present noise situation
are strongly recommended.
11-001
Pinter, I.
Orszagos Munkaegeszsegugyi
Intezet, Budapest /Hungary/
HEALTH PROBLEMS OF NOISE
IN MAN'S ENVIRONMENT
A Zaj Egeszsegugyi Problematikaja
az Ember Kornyezeteben
Orvostudomany
Vol 22 No 2:241-245, 197!
Noise measurements were recorded in
Budapest in schools, medical institutions,
and in the areas surrounding industrial
plants and airports.
Measurements were taken of outside
noise, chiefly from traffic, in 15
Budapest school buildings, 13 of which
were in the inner city, one on the main
traffic artery, and one on the outer
edge of the Capital in quiet
surroundings. Measurements were taken
two or three times in each school,
from 8 am to 4 pm, for a total of
eight hours per school. The dBA levels
and octave band levels were measured.
Noise was measured 2.5$ of the time, or
up to 1.5 minutes in an hour. With
one exception, the noise level of the
classrooms facing the street in inner
city schools exceeded medically sound
limits. Classrooms facing the
courtyard were observed 15 to 25 dBA
lower in noise pressure level.
Studies to determine the amount of noise
entering hospitals from the outside,
chiefly vehicular traffic noise, showed
that rooms facing the street had a noise
level approximately 40 dBA greater, in
certain cases, than rooms on the
courtyard. The noise level of the
hospitals far exceeded health norms,
especially in the 50 to 250 Hz octave
band. Only the suburban Korany
Tuberculosis Institute had a lower
noise level. (See Figure 1.)
Noise Level at 2nd Surgery Clinic (2SC)
and Nat'l Korany TB Inst (NKTBI) Measured in
Octave.,Bands with Windows_O^en and Closed
Medium Frequency Octave Band, Hz
Figure 1 ,
Noise measurements were taken in the
area of the Goldberger Textile
Printing plant which lies in the Obuda
reconstruction area in which a new
residential community is being
developed. Houses are to be built
40 to 50 meters from the north and
east sides of the plant. The purpose
of the tests was to serve as preliminary
data for noise protection in the new
houses and for noise abatement
measures to be executed in the plant.
Prevailing noise levels at various
times of the day were measured at
91 points on the streets bordering the
plant. Base noise was measured when
the plant was shut down. Most
measurements were taken at 1.5 meters
above the street. While the plant was
in operation, the noise level on the
north side was about 30 dBA above the
allowable daytime limits and about 40 dBA
above the allowable nighttime limits.
Noise measurements were taken at the
Budapest-Ferihegy International
Airport to establish the present noise
level and to project the aircraft noise
effect of a planned second runway on
nearly residents. Measurements were
taken on a direct line between the
runway and the Capital, mostly between
840 and 4200 meters from the end of
the runway. Four other measurement
points outside this area were also
used. Data were compiled on the
noise produced by 90 various types of
aircraft during take-off and landing.
Data were recorded on the maximum
level measured during an overflight,
the duration of the noise, the
number of planes and the time of day.
135
-------
11-002
DATA
Maximum noise level was measured in
octave bands and expressed in PNdB
(annoyance index). An evaluation
was made on the basis of the Wesf
German Sforindex Q which recommended
compatible land use planning for the
ai rport area.
11-002
L i n d be rg, Z. Y.
Berzinya, A. K.
Audere, A. K.
Rizhskiy Meditsinskiy Institut, Riga /USSR/
ON HEALTH CHARACTERISTICS OF THE
NOISE BACKGROUNDS IN RIGA
K Sanitarno-Gigiyennicheskoy Kharakteristike
Shumovogo Fona v g. Rige
Medits ina
Vol 288 No 7:134-137, 1971
The following table shows the percentage of
noise annoyance level:
Percentage of Annoyance
Source of Noise At Work On Street At Home
I ndustri a !
Construction
Street Traffic
Truck
Streetcar
Bus
Trol ley
Trains
Aircraft
Recreation
Home Equipment
Stores
11.07
7.41
8.62
2.7
5.01
0.82
0.09
0. 11
0.3
0.01
0.0
1 .3
14
8,
29
29.
4.
5.
1.
7.
3.
0.
0.
0.
.20
.54
.48
.48
.45
.01
,39
.30
.77
,68
.02
71
11 .69
1.08
66.73
16.32
43.68
6.05
0.23
8.31
3.80
1.85
2.01
3.12
TOTAL
28.82
97.69
Complaints seem to increase when the noise
level exceeds 50 dB.
Surveys and measurements were carried out
to determine the intensity of noise in Riga.
Measurements were made on the main
thoroughfares and residential areas, and
questionnaires dealing with various aspects
of noise were passed out to the public.
According to the data gathered, motor
vehicle noise ranged from 70-130 dB,
industrial noise 45-120 dB, and construction
noise 50-58 dB.
Transport noise seems to be the greatest
offender, commencing with aircraft noise
(over-city flights) 100-120 dB, trucks
70-100 dB, street-cars 75-110 dB, buses
60-90 dB, trolleys 70-75 dB, motorcycles
85-120 dB, motor bikes 90-115 dB. Maximum
noise levels were reached from 7-'0 am and
4-5 pm. Cobblestone streets are about 15-35
dB noiser than asphalt-paved streets.
The degree by which noise penetrates into
the surrounding buildings depend on the
sound Insulation of such structures:
-Greenery in front of building seems
to reduce the noise-I eve I by
5-15 dB,
-Windows facing away from the street can
eliminate the noise level by 15-25 dB,
-A good construction of windows and
doors can reduce the noise level by
7-30 dB.
The survey seems to indicate that transport
noise is considered the greatest source of
annoyance (67? of cases).
11-003
Ivanov, N. I.
Skorodumov, G. Ye.
Leningrad, USSR
HYGIENIC ASSESSMENT OF THE NOISE OF HEAVY
DUTY VEHICLES
Gigyenicheskaya Otsenka Shuma Tyazhelykh
Putevykh Mash in
Gigiyena i Sanitariya
Vol 35 No II:98-100, 1970
A hygienic assessment of the noise of heavy duty
vehicles in the USSR is presented.
The Bruel and Kjaer Sound level meter, which
makes third octave measurements, was used to
make cab and exterior (at 1,3,5 and 7 meters)
readings of several dozen tracked vehicle
types.
Diesel engine reading of 113-130 dB and work
area readings of 90-120 dB were taken. The
frequency bands were chiefly middle and high.
Diesel cab levels up to 102-104 dB were
recorded; other cab levels ranged from 96-113
dB; all are above the limits of the existing
standard.
Noise levels for other vehicles and their
work areas are reported and compared. All
levels exceed the existing standards.
136
-------
DATA
11-004
It is recommended that sound insulating
elements in cabs be increased by multilayer
construction of the cabs; that noise .insulation
of hoods be increased by 2-2i times; that
exhaust mufflers be installed on diesels; that
sound damping of diesel engines be increased;
and that cabs be vibration-insulated.
11-004
CampbelI, R. A.
Veterans Administration Hospital, Miami
On: A SURVEY OF NOISE LEVELS ON BOARD PLEASURE
BOATS
Sound and Vibration
Vol 6 No 2:28-29, 1972
A survey of noise on board 17 pleasure boats
ranging in length from 8 to 50 ft under normal
operating conditions showed that noise levels
typically render speech communication and
radio monitoring virtually impossible and
threaten hearing loss in cases where there is
prolonged daily exposure. There is also a
risk of accidents due to unheard spoken
commands. There was no clear relationship
between boat size and noise levels, nor between
type of construction material and noise levels.
Measurements were taken under four conditions:
1) quietest location on board at idling or
trolling speed; 2) quietest location at
cruising speed (calm and open water, slowest
speed at which boat would plane or
manufacturer's recommendation); 3) noisiest
location at cruising speed; 4) noisiest
location at maximum speed.
Noise levels ranged from 60 dBA in the front
cabin of a 36 ft cruiser at trolling speed to
104 dBA in the rear seat of a 15 ft open boat
with a 35 hp outboard at maximum speed.
(Figure 1 .)
TroMing speed
quietest location
Cruising speed
quietest location
noisiest location
Maximum speed
noisiest location
Range
(dBA)
60-79
85-104
Typ i caI
(dBA)
70
79
84
93
For references purposes, 70 dBA is the level
above which face to face speech communication
becomes difficult at distance of d few feet,
and 89 dBA, the level above which it ts
difficult or impossible to be understood at a
distance of a few inches. Noise levels above
89 dB were observed in 13 of the 17 boats at
maximum speed and in 8 boats at cruising
speed. Monitoring of radio-telephones was
difficult, and was routinely attempted in only
two of the eight boats so equipped. On These
two boats, the speaker was turned up so loud
that the level of radio static noise noasured
at the operators' heads was 94 dBA. Inese two
operators, both members of the Coast Guard
Auxiliary, reported that when not on patrol
they did not ordinarily monitor their radio-
telephones. The operators of the boats tested
were willing to accept the noise as a minor
nuisance when it was below the 85-90 dBA level,
but higher noise levels were complained about.
Sleep interference was not mentioned as a
problem because the boats were not slept on
wh i Ie unde rway.
With the exception of one noisier 15 f-f open
boat, noise levels seemed to vary little with
boat length in any of the four types of
measurement conditions, evidently because the
larger engines in larger boats offset the
effects of greater distances and more
intervening partitions. Nine boats were
fiberglass, five were wood, and three were
aluminum, but construction material did not
seem to affect noise levels.
The following measurement conditions were
observed: slow response on portable sound
level meter; microphone fitted with windscreen;
microphone held at head level of seated person
at from two to nine locations per boat,
including heads and helmsman's positions; alI
boats equiped with stock engines, with mufflers
installed on three boats; all boats operated
in ordinary fashion: engine covers in place,
cabin hatches open, head doors closed, normal
equipment including seat cushions and matresses
in pi ace.
Noise levels were also measured within one foot
of an outboard engine or inside the engine
compartment of an inboard, these ranged from
100 to 115 dBA, thus constituting a serious
hearing loss threat to mechanics regularly
servicing marine engines while they are running.
There are about 8,000,000 power pleasure boats
in the U.S. Even if the risk of hearing loss
to the operators is ignored, the risks of poor
speech communication (loss of a total boat ana
its occupants because of missed voice commands
137
-------
11-005
DATA
or warnings) is not acceptable. The range of
cruising speed noise levels found in these
boa-'-s is similar to that found in airline jet
aircraft cockpits (81-96 dBA). Standards
suggested for cockpit noise (by R. B. Stone,
Aerospace Medicine 40,989-993,SEPT, 1969) are
90 dBA maximum and 85 dBA for normal cruising;
these would guard against hearing loss and
insure close-range speech communication,
although with difficulty. Such standards are
directly applicable to power boats.
11-005
Oesterre'chischer Arbeitsring fuer
Laermbekaemptung, Vienna /Austria/
1012 v'iema, Ctubenring 1, Austria
LESS NOISY CONSTRUCTION OPERATION
Laermarmer Baubetrieb
Ossterreichischer Arbeitsring fuer
Laermbekaempfung Industrie-RichtIinie
2nd ed., Vienna, No. 111, APR 1970, 11p.
Maintenance is an important factor of noise
abatement. All plates should always be well
fastened and the sound dampers and gears always
clean. Correct lubrication preserves machinery
and helps to reduce noise. Bi-annually, all
machinery should be inspected and overhauled
to insure that all of the noise-preventive
measures are operating properly.
For huge equipment, tents and shields are
recommended as noise reducing devices.
Shields, of course, can dampen the noise only
against one direction. In order to be
effective they must be at least 3x3 sq. m
and consist of materials such as iron sheet
with 5-8 cm fiber wool behind perforated
sheet metal; such outfitting can reduce the
noise level by 5 dB.
Tents consisting of plastic mats with mineral
fiber filling or foam filling can reduce the
noise level by 10 dB. Huts of light wood
construction can achieve noise reduction of
20 dB.
In planning a construction operation all of
these measures must be taken into consideration
by the firm and the architect involved in order
to avoid any unnecessary and undesirable noise
levels and conditions.
It is the task of technology to offer unlimited
safe working conditions to the worker in all
types of operations.
The best means for noise reduction is to take
measures right at the source, by means of
screening, encasing, etc. Noise levels are
listed for various construction machines
measured a* 1 meter, ranging from 75-85 dBA
for a socket wrench to 120-125 dBA for a
compressed air pile driver. At 7 meters the
noise level should be 15 db lower.
Since noise levels are much more disturbing
during the night, construction work should be
avoided and if it is absolutely necessary, it
should be executed only with quieter equipment.
These are some of the recommended noise levels:
Area
Quiet area
(residential,
Downtown area
Industrial area
Permissible Noise Levels
Day (dBA) Night (dBA)
vi Ilage)
50
60
65
40
50
55
Noise reduction methods are given for
particular individual pieces of equipment.
For instance, whenever possible, combustion
engines should be replaced by electrical
motors. For all equipment such as concrete
mixers, hammers, etc. the same is recommended.
All internal combustion engines may be
equipped with special effective sound dampers
for the exhaust area, as well as the induction
s ide.
11-006
Young, J. R.
Stanford Research Institute,
Menlo Park, CA
Sensory Sciences Research Div., Zip 94025
ATTENUATION OF AIRCRAFT NOISE BY WOOD-SIDED
AND BRICK-VENEERED FRAME HOUSES
Springfield, VA, NTIS, N70-32694, 1970, 37p.
HC: $3.00 MF: 95 cents
Attenuation characteristics of a typical brick
veneer house and a typical wood-sided house
were measured for aircraft noise during the
course of a NASA study of the subjective
evaluation of aircraft noises. The differen-
types of aircraft, a four engine propel lor-
driven Lockheed 1049G, and a four engine
turbofan jet CV-880 were used as the noise
sources. They flew runs directly over the
houses on straight and level flights at
altitudes of 1200 and 2000 feet, respectively.
It was found that in any one-third octave
band of frequencies, the maximum noise outdoors
did not occur at exactly the same time as the
maximum level indoors. Attenuation could thus
be defined ir. several different ways. The
best descripfor of tie effect of the test
house structure on the aircraft noise,
measured inside the -louse, was found to be
138
-------
DATA
11-007
house attenuation defined on a 1/3 octave
band basis by the difference between an
outdoor band maximum and an indoor band
maximum, without regard for when these
maxima occur. Eight indoor locations, two
for each of four rooms, were used.
Measurements were collated so that four
estimates of attenuation were available for
each room. From these estimates, average
attenuations in each band were calculated, and
these average values were used in turn to
plot house and room attenuation characteristics.
The two one story houses were tested with
windows and doors closed and with completely
furnished rooms—carpets, drapes, and the
normal complement of tables, chairs, etc.
The following table shows samples of typical
results of attenuation for the houses (peak
measure statistics, data from four flybys):
Place
BRICK VENEER
Dining room
Living room
Bedroom No. 1
Bedroom No. 2
WOOD-SIDED
Dining room
Living room
Bedroom No. 1
Bedroom No. 2
A-weighted level
Avg., dBA Std. dev., dBA
22.6
20.9
27.1
25.6
20.7
19. 1
24.3
17.3
3.0
4.5
2.6
1.1
0.7
1 .1
1 .9
2.6
Results evaluated in PNdB were within 1-2 dB of
the results expressed in dBA. The house
attenuation numbers obtained in this study
correlated within 2 dB of those given in SAE
document AIR 1081 (1969) for houses in Boston,
New York, Los Angeles, and Miami, with various
numbers of rooms.
A measure of how useful the attenuation data
were for predicting indoor noise levels was
made by weighting outdoor data with the
attenuation characteristic for each room to
compute the estimated indoor levels. A
comparison between the estimated and actual
values showed that the attenuation data are
useful for indoor noise prediction purposes.
11-007
Greater London Council /England/
The County Hall, London SEI
INDUSTRIAL NOISE: REFUSE TREATMENT PLANT
Urban Design Bulletin (London)
No 2, 1970
The Greater London CounciI wi I I use a standard
method of calculating probable communify
annoyance caused by industrial noise in
planning a series of government-owned
industrial plants. In the course of its design
work on refuse treatment plants, it has
published design guidelines illustrating how a
hypothetical plant might be planned (Figure 1).
fit 1 S>Nplino'*nlneu»fllKInpl«l
The standard method used is British Standard
BS 4142:1967, upon wnich the International
Standards Organization (ISO) draft Resolution
1996 is closely patterned. This standard
states that complaints may arise if a new
noise source is introduced to an area,
resulting in a rise in excess of 10 dBA over
the existing background noise levels,
measured just outside the nearest residential
bui Idings. However, in sensitive areas a
possible increase of 5 dBA should be viewed
with caution, because of other possible
insidious rises in background noise levels.
In calculating the noise of a proposed plant,
the level at the site boundary must be adjusted
for duration, presence of pure tones, and
periods of louder or more disturbing noise.
The adjusted caleu I a fed level is then compared
to the background level to judge if the plant
will be suitable. If background levels can not
be measured, a basic criterion of 50 dBA may be
used, which is then corrected according to the
type of district (ranging from purely
residential to industrial).
In planning the refuse treatment plant,
designers relied on noise survey data from
three existing plants and one French plant,
as well as information derived from
manufacturers (see figure 2).
They then used a variety of methods to plan a
plant that would meet BS 4142.
First, noisy processes are concentrated within
a building with walls as imperforate as
possible and with adequate acoustic insulation.
139
-------
11-008
DATA
Windows are minimal in area, on the side of the
building away from nearby noise-sensitive
areas only, and sealed. Second, noisy processes
are located within the site in such a way as to
minimize their noise emissions in a particular
direction, in this case, in the direction of a
hospital to the southeast. Other buildings act
as shields, and one retaining wall and earth
bank is provided to shield the noise from
extensive unloading activity by dump trucks.
C - Castle Brwnwich Refuse Disposal Workt.
D - Direcl Incineralion Plant Derby
P - Usine d'lssy-lef-MouhneauK. Pans
M - Manufacturers Information
F - Folkstone Road Refuse Pulveriser London. E 6
•Plant Noise LevHi
Fin 2.
I External Measurements
Flint
1 Refuse vehicle starting
2 Refuse vehicle on level
ground, steady speed
3 Refuse vehicle on slope,
steady speed
4 Forced draught fan
5 Induced draught fan
6 Cooling tower
7 Cooling tower
8. Cooling tower
9 General plant noise'
(mosily de-duster)
10 General plant rio.se1
11 General plant none '
12 General plant noise '
13 Residuals
(conveyor and chute)
14Sevefalveh.de*
discharging
15 Magnetic separators
+ clinker & fly
ash conveyor
16 Pulveriser only
17 Vibraiory feeder
18 Pulverizer with
vibratory feeder in
Location
at 7 5 metres
at 7 5 metres
at 7 5 metre*
at 3 metre,
at 3 metres
at 30 metres facing
louvres
at 130 metres facing
louvres
at 270 metres facing
'ouvret
at 110 metres from
wall
at 300 metres from
plant
al 50 metres from
plant
at 1 00 metres appro x
at 10 metr«
entrance (outside
reception had
at 10 metres
at 10 metres
at ID metres
at 10 metres
Noise itvet
84dB(A)
80 dBIA)
83dB(AI
76dB(A)
71 dBIA)
69dB(A)
60 dB.A)
54 dB(A)
52-53 dB(A)
45-46 dBIA)
(Hum of de -duster
Clearly audible)
57 dB(A)
S3 dBIA)
75dB(Al
62 dB(A)
B2dB(A)
70dB(A)
81-82 dB(A|
79-83 dB(A>
S/»
C
C
C8.D
C
C
M
M
M
C
C
D
P
0
C
P
F
F
F
b Internal Plant Noi»r
1 Metal press
2 Cardboard press
3 Induced draught fan in
reverberant conditions
4 Collection vehicle,
tipping
5 Water pump, reverberant
c Internal Environmental
fttdbffwurirjiou.ioutt.
1 3 vehicles discharging
2 One conveyor plus
3 Conveyor
4 General plant noise *
5 General plant noise '
6 General plant noise '
7 Refuse feed chute
8 4 bo.ien in use
9 Turbines
at 3 metres
M 3 metre*
at 3 metres
at 3 metres appro*
at 3 metres
Noise Levels
Locrton
Reception hall
on 'bridge'
In elevator room
on 'bridge'
Inside separation
Incinerat.onr-om
(by control desk)
,±r mcineri"'on
.ns,de bo.ler house
Inside turbine hall
84-86 dB(A)
(mostly clangs)
86- 88 dBIA)
91 dB(A)
90-92 dBIA)
91 dB(A|
Notx level
88-91 dBIA)
87dB(A)
79 dBIA)
89-91 d8{A)
7B-82dS(A)
BOdB(A)
IQOdB(A)
81 dB(A)
88 dBIA)
C
C&D
0
D
D
&(*
C
C
C
C
c
D
0
P
P
11-008
Schirmer, W.
Biehn, K.
VEB RFT Messelektronik, Dresden /East Germany/
NOISE SITUATION IN TYPEWRITER TECHNIQUE
Zur Laermsituation in der Schreibmaschinen-
techni k
Fei ngeraetetechni k
Vol 18 No 11:510-516, 1969
Methods used by the office-equipment industry
of the German Democratic Republic to reduce
noise-levels are discussed. Numerous noise-
measurements were carried out on typewriters.
For this purpose, a cabin 3.5 x 4.5 m. and
about 2.5 meters high was employed and
measurements were taken 1 meter from the
noise source by means of the precision impulse-
audiometers fype PSI 101 and PS I 202 installed
by VEB RFT Measuring Electronics, Dresden.
The machines were placed on a 650 mm high table
covered with a plate of 500 x 500 x 20 mm size
consisting o* 200 mm thick foam and 15 mm thick
felt materials. By this means, only the
typewriter noise is captured. The distance
between microphone and the source is 4 m.
The type of stroke and the speed play an
important role in the measurement. The range
of the speed and the troke stresses the
difference in typing. A normal text can vary
up to 6 dB.
It is thus recommended that the same typist be
used in determining the noise-I eve I
measurements.
It was determined that for a significant
difference of about 2 dB between 2 mean values,
10 individual measurements are required to
achieve about a 95% accuracy.
The main source of typing noise is the impact of
the type bar on the recoi I ring and the type
impact on writing-roll. Speed plays an
important role in the above.
Measures taken to combat this type of noise are
to compress felt material with lead around the
recoiI ri ng.
140
-------
DATA
11-009
The noise caused by manipulating the space-bar
can range from 10-25 dB: in portable
typewriters, about 20 dB; office typewriters,
25 dB, and electric typewriters, about 20 dB.
The next source is shifting, which again can
range from 10-20 dB. Investigations were made
on portable-typewriters with plastic casing and
electric typewriters with metal casing. The
parts of the absorbers consist of Moos-rubber
layers.
The movable parts of the machine should be
made of lighter material instead of heavy ones.
Damping by means of plastic and metal casing
seems so far to be most useful.
Impulse-Noise Measurements
Type of
Mach i ne
Portable
Typewri ter
Office
Typewriter
Range of Noise
Level
78 83 dBAI
87 89 dBAI
Mean Va I ue
83 dBAI
88 dBAI
Impulse-Noise Measurements
Function
Typ i ng Noise
Space Bar
Sh i fti ng
Carri age
Hoist
Idling Noi se
Standard
Typewri ter
82 dBAI
60 dBAI
60 dBAI
60 dBAI
Electric
Typewriter
85 dBAI
67 dBAI
62 dBAI
77 dBAI
60 dBAI
35 dBAI
11-009
Vargov i ck , R. J .
Ford Motor Co., Dearborn, Ml
P.O. Box 2053-K237.0 Zip. 48121
NOISE SOURCE DEFINITION - EXTERIOR PASSENGER
VEHICLE NOISE
New York, Society of Automotive Engineers,
1972, 8 p.
Recent studies have indicated that the
passenger vehicle is a major contributor to the
annoyance of traffic noise. A test series was
conducted at the Ford Michigan Proving Grounds
on a concrete surface. The purpose of the
test program was to determine the contribution
of each car noise source. A 1970 high and low
power sedan and a high and low-power sporty
compact were used in the test.
The results of the test show that, for wide open
throttle conditions, engine/exhaust noise
predominates, being 14 dBA above the other
noise sources. Adding another muffler in
series resulted in a sound level redudion of
6 dBA. The engine contributes about 50* of the
total noise below 500 Hz. Tire/road noise is
the major source above 500 Hz. The contributor
of the cooling fan to the total exterior vehicle
noise at cruise is negligibte at alI
frequencies. This conclusion was true for all
engine/vehicle combinations fesfed except the
low power sedan at 65 mph. The tires used in
this study we re typical, original equipment,
bias-belted tires.
The most immediate reduction in levels is
required for trucks, with a reduction of exhaust-
noise as the first goal. A reduction of 16 cB
corresponds to eliminating 97% of the noise
energy emitted. Additional data are needed to
determine the true variation of tire/roadway
noise with speed and thus formulate more
accurately the noise generation model for this
source of noi se.
11-010
Wojtowicz, R.
Zaklad Projektowania Budynkow Sluzby
Zdrowia, Politechnika, Gdansk /Poland/
Poznan
THE PROBLEM OF LOW INTENSITY IMPULSE NOISES
IN HOSPITALS
Zagadnienie halasow impulsowych niskiej
intensywnosci w szpitaiu
Przeglad Lekarski
Vol 25 No 2 255-258, 1969
An investigation was carried out in Poland en
the.major acoustical problem of hospitals and
their construction. Part of its was based
on measurements and on the replies to a
questionnaire sent to 465 physicians engaged
in 25 various departments of 22 hospitals.
Of the inquiries, 47.5^ involved clinical
hospitals, 23.5% regional and the rest
municipal hospitals. The time of this
particular survey was the fall-winter
season when a I I the windows had to be
closed.
Many noise sources (38) were investigated and
some of them compiled into charts on noise
impulses.
141
-------
11-011
DATA
Noise Source
Levels (dBA)
Hospital
Freeway
Distance
(feet)
1. Trolley-street car
2. rush hour
3. street noise 50-80
"». slamming of doors
5. walking in heavy boots
6. ambulance sirens
7. squeaking floor 50-60
8. visiting hour
Noise Source Level (dBA)
1. Radio & TV
2. Refuse removal up to 90
3. School
4. Recreational areas
5. Cleaning
6. Dormitory (for nurses
& medics) 60-85
1. Calls in the ha I Is
All the studies were based on the Chocholle
criterion. Hospitals are built inadequately
and require much better insulation and
architectural design, since what is considered
to be tolerable noise level for a healthy
individual is unbearable and damaging for a
patient. The study showed that impulse noise
levels in the hospitals exceeded norm
PN-63/B-02151.
Noise Level,
dBA (windows
open)
Queen of
Angels (7th
floor)
Deaconess
(7th floor)
S.F. County
(4th floor)
Loretto
St. Lukes
(2nd floor)
Hoilywood
(11,000-
11,600
veh icles/hr)
3rd Ave
(1500
veh icles/hr)
Bayshore
(5,000-
13,000
veh icles/hr)
Congress
(5,000-
8,000
veh icles/hr)
Congress
(8,000-
10,000
veh icles/hr)
400
400
300
200
150
67*
55
60
60
61
* hospital on hill above freeway
For purposes of comparison, data on two air
conditioned buildings with sealed windows are:
48 dBA at 300 feet (6th floor); 43 dBA at 150
feet (2nd floor). With the windows open, the
noise levels were in the 60 dBA range; this is
5-7 dBA higher than what would be expected for
residential under similar conditions. The
possible reasons for the higher levels in
hospitals are first, that these particular
freeways may have had a higher volume of
truck traffic; second, that there was an
unobstructed sound path; or third, that
background noise generated inside the hospital
was not taken into account.
11-01 1
Lane, S. R.
California Univ., Los Angeles
School of Arch, and Urban Planning, Zip 90024
On: NOISE INSIDE HOSPITALS FROM FREEWAYS
In: Lane, S, Freeway and Highway Noises: an
Information Base for Urban Development Decisions
Springfield, VA, NTIS, PB 204434, 1971, 90p.
(p. 36-38)
Data were obtained on noise levels in Los
Angeles hospital rooms, most of which were
upper rooms facing a freeway and with a direct
view of the freeway. The ground distances from
the hospitals to the freeways ranged from 140-
400 feet.
12-001
Rylander, R.
National Inst. For Public Health, Stockholm
/Sweden/
Dept. of Environmental Hygiene,
10401 Stockholm 60
SONIC BOOM EXPOSURE EFFECTS 1.1: INTRODUCTION
Journal of Sound and Vibration
Vol 20 No 4:477-484, 1972
The workshop on sonic boom exposure effects
was convened at Saltsjobaden, Sweden, SEPT
7-9, 1971.
142
-------
12-002
GENERAL
The sonic boom can affect the health of man
directly or indirectly. The prospects are
relatively bright for technical developements
which will limit the exposure to acceptable
levels, and which will allow the establishment
of an exposure control system. Considerable
research efforts have been and are being spent
to understand the effects of exposure to sonic
booms. The workshop was held in the
knowledge that the sonic boom is a basic type
of acoustic stimulus affecting structures,
animals and humans. Consequently the results
achieved from the workshop on sonic booms
should also be applicable to a range of
industrial and other environments where sudden
bursts of noise are present.
The distinction between performance tests and
development tests must be emphasized. A
performance test is carried out to determine
whether or not a product in development has
met its acoustical objectives or specifications.
A development test is conducted by engineering
personnel to guide the design of the noise
control features that must be incorporated
into the new product.
Noise control techniques can be applied to
almost any product, but not without an
economic penalty. If noise control is an
afterthought, the economic penalty is
frequently excessive. Early application
of noise control in a project may minimize
cost for the quietizing features. The
conclusion is drawn that technological
factors are no longer placing a limit on
the control of product noise.
12-002
Lang, W. W.
IBM Acoustics Lab., Poughkeepsie, NY
P. 0. Box 390, Building 704,
Zip 12602
PRODUCT NOISE AND ITS CONTROL
At: American Association for the Advancement of
Science, 138th Meeting, Philadelphia, DEC 29,
1971
Poughkeepsie, IBM Acoustics Lab., 1971, 14 p.
The methods used in a product noise control
program are discussed. The program stresses:
1) the right tools to do the job,
2) the appropriate skills of trained personnel,
3) the motivation to develop a quietized
product and, 4) an early start on the
engineering aspects of noise control.
The development of a quietized product requires
the skills of a team of noise control engineers,
an engineering specialty requiring both formal
training and practical experience.
The motivation to develop a quietized product
is embodied in the acoustical objectives and
specifications for the product. Experience has
shown that without quantitative criteria to
guide the development of a new product, the
desired result is seldom achieved.
The fourth ingredient of a successful program
is an early start on the engineering aspects
of noise control. To achieve the most effective
noise reduction at minimum cost, noise control
features must be carefully planned and
incorporated into the design of the new
product as early as possible. An evaluation of
the new product should be made by skilled
noise control engineers.
12-003
THE DIN OVER MUFFLING NOISE
Business Week
APR 8, 1972, p. 32
Under force of the Occupational Safety and
Health Act, standards have already been set
which limit the amount of noise to which
workers are exposed. The field of product
design, except for airplanes, however, is
totally void of any such standards, and
as a result it is the consumer who pays
the price for noisy equipment. In its
report on noise under the Clean Air Act of
1970, the EPA pinpointed construction
equipment, trucks, motorcycles and off-
the-road vehicles for chief focus. State
and city regulation against noise have
appeared, and some are getting tougher.
California, for instance, will drop its 88
dBA limit on cars and trucks to 83 dBA
by 1975 (measured at 50 feet). Most
manufacturers favor EPA action to keep an
unwieldy patch work of local regulations
from spreading. The cost of noise
abatement and control will not be cheap.
With all the muffling and vibration damping
necessary for a 10 dB decrease in noise, one
manufacturer estimates that the price of a
$5,000 diesel would go up $1500. Another
estimate is that it will cost an additional
$30-$50 per car and up to $125 per truck for
auto makers to meet California's 1973 limits
of 86 dBA.
One aspect of more Federal legislation also
bothers manufacturers. The auto makers, in
particular, are concerned that the government
may not coordinate its demands on noise, air
pollution, and safety. For example, catalytic
air cleaning devices may compete with sound
deadners for limited space in cars.
143
-------
12-004
GENERAL
A second noise source, tires, becomes the
dominant source above approximately 35 mpn,
and noise regulations may eventually focus
on it.
12-004
Toole, F.E.
Brammer, A.J.
National Research Council of Canada,
Ottawa /Ontario/
Div. of Physics, Montreal Road, Ottawa 7
THE "NOISE THERMOMETER": A LARGE-DISPLAY SOUND
LEVEL METER
At: Acoustical Society of America, 82nd Meeting,
Denver, OCT 22, 1971
Ottawa, National Research Council, 197?, 10 p.
A large-display sound level meter to be used for
educating the public as an aid to enforcing
noise laws is described. A prototype of such
a display has been developed by the National
Research CounciI (NRC) of Canada and tested on
the NRC's grounds and by the city of Edmonton,
Alberta.
Although much anti-noise legislation is based on
measurements in dBA, the average citizen often
lacks even an approximate subjective
interpretation of quantitative limits expressed
in dBA.
The complete display is called a "noise
thermometer" and consists of an 8 ft tall display
sign and a remote microphone unit. The acoustic
input is converted into a column of lights that
looks similar to the column of mercury in a
thermometer. The display registers from 70-100
dBA in 2 dBA steps. As the sound level rises
as a vehicle approaches the microphone, the
display develops in 2 dBA increments. The
maximum level is sensed and the full display is
retained for approximately 4 seconds to enable
the driver to observe the level produced by his
vehicle (Figure 1).
Silhouettes attached beside the column of lights
indicate maximum levels permitted by state or
local law for various classes of vehicle.
However, if the law is complex (for example,
specifying different levels at different
speeds), use of the silhouettes is not
advisable.
display; however, the meter can be used as a
check on the calibration of the display. The
circuitry of the display is such that the onset
time is similar to that of a sound level meter
on "fast" response. But the response to
transient signals is slightly faster than a
sound level meter on "fast," resulting in an
exagerated reading for highly impulsive sounds
such as those generated by many motorcycles and
some unmuffled trucks. This error is in a
desirable direction and should not be corrected.
The display will operate with an accuracy of ±
2 dBA within a temperature range of 45-90
degrees F.
The "noise thermometer" was used during the
summers of 1969 and 1970 within the NRC grounds
in Ottawa. Many potential offenders of the
Ottawa City By-Law were observed travelling to
the test site to check out their vehicles, and
some motorcyclists even performed modifications
on the spot.
In Edmonton, Alberta, the display has been used
over 1 million times in five months to publicize
the city's new anti-noise legislation. During
the first six weeks of the campaign, the site
of the "noise thermometer" was changed
frequently, with the news media publicizing each
change and restating the purpose for the device.
One source of concern had been that a possible
slowing-up of traffic in the vicinity of the
"noise thermometer" would lead to congestion and
an unsafe interruption in the traffic flow.
However, although the device attracted increased
traffic, no serious congestion has been
reported.
Display Cleared
""and Ready for
Hext Vehicle
The microphone is situated at a distance from
the traffic that is relevant to the local noise
regulation. Within the microphone housing is
a sound level meter (Bruel and Kj'aer model 2205)
that functions only as a microphone and
amplifier for the circuitry housed within the
144
-------
12-005
GENERAL
12-005
Zimmerman, '-1. 0,
THE POLLUTION PANIC HITS HOME
Machine Design
Vol 43 No 24:19-21, 1971
Environmental noise has been doubling ever/
10 years and the noise levels in domestic
quarters are beginning to approach those
in factories. Kitchen and household
appliances contribute to the moooi and
outdoor noise environment of the home.
Makers of household appliances are already
working to quiet such noisy products as
blenders, exhaust fans, mixers, garbage
disposers, and dishwashers.
Methods for controlling Hie noise levels
of such appliances include yioration-damp ing
mounts, insulating fiberglass shields, lower
motor speeds, and the relocation of noisy
components within machinen/. The use of
rotary heat excnangers in ->• -,ond ' f loners
may i ncrease.
Strict noise ordinances exist in Memphis and
Coral Gables. Chicago set a maximum permissible
noise level for new outdoor power equipment
•_cid ir the city at 74 dBA.
A paper on Pi-ob'ems of Noise Meas ire ,~ if"
in Construction Machinery wa.j pr?<'~ *~ : oy
Dr. K. S/ynaniki. The discus . , wr,,^ <.,!
clearly Pressed uaust'-y's rr ,
lower the noise l-'-yc-ls ,• • i r , , „•
During the conference, Bruel and Kjae'' of
Denmark presented an exh'bit or all rr.ei;
I'-easut i r j cqu i pme'i r. ar c the G • 1 i ' ; V • ' A i-
of Sweden d i sp I av ^ i rhei r aeon - r i •- ; • t i
vibration insulari-,' mater ,1-
Bolt, Beranek, and Newman, Inc.
Cambridge, MA
12-006
Raj chert, W.
Warsaw, Ul. Lwowska K
CONFERENCE ON THE ThE'T OF NOISE ABATEMENT
Konferencja nt. Zw,- I <.^ en I a Halasu
Problemy Rozwoju Budowrii; fwa
Vol 5 No 6.49-50, 19AO
A conference on No'sc "c; France, U. S., Sweden,
Hungary and Italv. p total, there were over
300 Durtir.p-jnK •'-': f=^-nting the industrial,
science and res'V^r'i rields.
The role of the ncise r'vi"*"•'' ,onsult3r
obviously must fe th^t of a probU-
solver, but it i ,o ",•_',t h^ fr^t of
counselor, educaf^jr and advisor. He
must see to it that noise control efforts
will be conauc t ed toward reaI i -^ i;
goals thar are compatible wi+h ^he law
and wilh tne on-going objectives of the
client. A great advantage ot the noise
control consultant is Ms exper ^neo
an*"- his f r oecorn to recorin^i (l a h^i , ^ >
o^ a I f" r nat, ve sc I ut i ^. i .
There are not cn_unn nc i ^e cci'~iio'
e n g i n ee rs I o s c i vc e x i -; ^ i' i g i n d , ' * i -i
problems, eHtv,_r ^-, > :.dep£ ^'{^n~
consu'Tartj o1 as adu.'i^ • iu M ju_- : ' -. i
staff, so it wih fji lo iruu^Tiy 1,1 -DC
end to solve n\.,_-t problem? v» i4 % ,'r'oLse
pe rsci'iio ; . I' t r-r* i r i - r i n,
consultant can pro^ioo sclu'it i, i: t ^
most i iTiiTieu i ate probleri'S ufuj ;t rne sane
time use these problems as nf3r,:, tor
educjriuy I he clienl': sTcfi.
The rrost progress is made when a
consultant, tarriiliar wirh noise cent.-'
materials, methods, and mtatij, vV'fks
intimately with mcrr.be rs "it the s M ei^ ' >
145
-------
12-008
GENERAL
staff, who know the requirements imposed
by production and process control. Only
then can solutions be expected to be
compatible with space, costs, operating
personnel, and long-range production goals.
Often an independent voice is needed to
aid in deciding internal questions to
support a position in a court of law. The
consultant can serve here as an unbiased
expert.
12-008
THE GREAT OFFENSIVE OF THE "NOISE SPIES"
Grossoffensive der Laermspione
Die Presse
Vienna, SEPT 18, 1971
An article reports on an international
noise conference of 100 noise experts,
held in Vienna. The Congress was
promoted by the International Standards
Organization and organized by the
Austrian Standards Institute with the
assistance of Professor Bruckmayer of the
Technical University of Graz and Dr.
Judith Lang of the Noise Control Institute
of the Technical Industrial Museum of
Vienna.
The Congress plans to produce a noise
catalogue and set bases for legal
measures which should effectively protect
individuals from noise-induced health
hazards. The main chapter shall contain
thorough coverage of aviation noise, as
well as noise from heating and refrigeration
equipment, and include protective devices.
It shall also deal with the necessary
guidelines on all noise sources.
As a first step toward effective noise
protection the experts plan to carry
out more precise measurements and set up
noise level survey charts.
The most important task of the Congress
is to formulate International Norms.
146
-------
SUBJECT INDEX
Abatement Devices 02-010
07-007
10-010
12-006
Acoustic Consultants ' 12-007
Acoustic Damping 00-033
01-013
01-023
05-002
10-001
Acoustic Dampers 01-021
01-025
11-005
Acoustic Engineering 12-002
12-007
Acoustic Stimuli 12-001
Acoustic Trauma 02-002
02-006
Adaptation 02-005
03-017
Agricultural Equipment 00-020
Ai r Bags 00-025
Air Conditioners 06-006
07-017
Aircraft 00-016
00-035
02-012
04-003
07-001
07-012
07-015
10-004
Ai rcraft Noise 00-007
00-008
00-013
00-024
01-004
01-017
01-018
03-001
03-009
03-02?
04-005
05-003
06-007
147
-------
Aircraft Noise (Continued) 06-011
07-002
07-004
08-005
08-007
10-001
10-002
10-006
10-008
10-009
Airport Noise 00-007
02-012
03-015
07-004
07-008
07-015
08-001
10-002
11-001
Airport Siting 10-001
10-009
Amplified Music 02-008
Animals, Effects On 00-026
02-016
03-003
Annoyance 00-031
02-015
03-003
03-006
03-012
03-013
03-014
03-015
03-016
06-009
06-013
11-002
Appliances 12-005
Architectural Design 03-019
05-002
05-003
07-007
Arousal Response 02-007
Astronauts 03-010
Attenuation 06-008
06-012
11-006
148
-------
Audiological Investigations 03-001
Auditory Awakening Threshold 02-007
03-007
03-010
03-011
Auditory Preception 03-006
Austria
Automobi les 01-010
07-012
07-013
11-009
Awakening Effects 02-007
Background Noise 02-017
Barriers 06-010
07-010
07-011
07-012
Boats 00-018
00-019
11-004
Bui Idi ng Codes 00-013
08-007
Buses 01-013
10-010
Canada 01-008
01-014
01-015
12-004
Central Nervous System 03-018
03-023
Chicago 01-025
08-011
08-012
12-005
Chi Idren 00-006
00-022
City Planning 00-015
01-027
06-004
07-001
07-006
07-016
07-018
149
-------
Community Noise 00-008
00-027
01-018
01-022
02-009
03-002
03-015
06-003
06-009
07-009
08-001
08-009
10-002
10-007
Compressors 01-022
Computer Printers 01-016
Conoids 01-007
Construction Equipment 00-002
00-003
00-004
00-032
01-001
01-005
04-001
06-005
11-005
Construction Material 00-014
Construction Noise 00-012
01-005
01-025
04-001
Continuous Noise 03-018
Cost-Benefits 00-004
00-023
00-036
01-027
Cost Penalty 00-001
00-002
00-003
Costs 00-017
00-020
00-030
00-032
00-033
00-035
01-013
04-002
150
-------
Costs (Continued) 04-001
05-002
07-002
07-010
10-004
12-003
Court Claims 08-006
Criteria 02-009
06-009
06-013
08-008
11-004
11-005
11-007
Damage Risk Criteria 02-006
03-021
08-003
Diesel Engines 01-013
11-003
Diesel Locomotives 01-011
Discotheques 02-002
Economics 00-001
00-002
00-003
00-004
00-023
01-027
03-022
04-004
06-006
07-007
10-005
12-002
Education 00-006
00-015
00-020
09-004
Enclosures 01-025
Enforcement 00-021
00-029
09-001
09-002
10-006
Engine Design 01-006
England 01-006
151
-------
England (Continued) 11-007
Environmental Protection Agency 00-012
00-024
00-028
00-033
09-002
EquiIibri urn 02-013
Europe 00-034
Explosives 00-022
Exposure Effects 02-009
12-001
Fan Noise 01-012
Fatigue 02-003
02-014
03-017
Federal Aviation Administration 00-024
Forest Noise 01-014
01-015
Gaussian Distribution 08-003
Generators 01-026
Germany/East 02-004
11-008
Germany/West 01-004
07-004
07-017
08-002
08-010
10-005
10-007
10-008
10-010
Ground Absorption 07-003
Guidelines 06-001
12-008
Hearing Loss 00-022
02-009
02-014
03-020
06-012
11-004
152
-------
Hearing Protectors 00-020
03-001
Heathrow Airport 10-009
Helicopter Noise 01-017
High Frequency Noise 02-005
02-007
Highway Design
IndustriaI PI ant Desi gn
Highway Noise 00-010
07-003
07-005
07-013
08-002
Highway Planning
Hospitals 03-016
07-017
11-010
11-011
Hous i ng
Hungary
Impact Noi se
ImpuIse Noi se
Industrial Noise
153
-------
Insulation 01-016
05-001
05-005
11-002
Intel Iigibi Iity 03-001
03-005
06-011
11-004
Intermittent Noise 02-015
Israel 10-003
Italy 03-004
Japan 02-015
03-005
03-008
03-021
07-011
Jet Engines 07-008
Land Use 00-009
07-001
Lawn Mowers 00-019
01-024
02-009
Legislation, Federal 00-005
00-007
00-010
00-011
00-013
00-021
00-024
00-027
00-029
00-037
08-005
08-008
10-004
12-003
Legislation Foreign 00-034
01-002
08-002
09-004
10-003
Legislation, Local 00-005
00-021
00-027
00-038
08-001
154
-------
Legislation, Local (Continued) 08-005
08-006
08-011
08-012
09-003
12-005
Legislation, State 00-005
00-037
09-012
Litigation 08-005
Logging Noise 01 -008
01-014
01-015
Los Angeles 07-005
07-013
11-011
Louvers 01 -012
Machinery Noise 01-003
01-008
01-014
01-016
05-005
06-002
07-014
11-008
12 006
Masking Effect 03-001
06-011
Masking Noise Systems 05-001
Mass Transit 10-010
Measuring Techniques 00-016
06-005
Mental Performance 03-005
Mining 02-010
Monitoring System 00-035
06-007
Motor Vehicles 00-021
00-031
00-034
00-037
01-006
01-010
03-012
155
-------
l"fotor Vehicles (Continued) 05-004
OG-004
07-012
07-013
08-011
11-009
12--003
12-004
Motor Vehicle Noise
Mufflers 00-001
01-021
01-022
01 -024
Neoprene
New York City 00-038
Noise Abatement
Noise Control 00-011
00-018
00-020
00-028
00-038
01-019
01-020
06 -002
12-006
12-007
Noise Control Programs 00-005
00-030
09-004
10-005
12-002
12-007
156
-------
Noise Exposure 02-008
02-009
06-007
08-001
12-001
Noise Intensity 08--003
Moise I sol ati on
Noise Measurements 00-008
01-002
06-001
06-003
06-008
06-013
07-003
07-018
10-007
11-003
12-004
Noise Po!lution 00-006
00-036
Noise Reduction 01-003
01-009
01-010
01-011
01-016
01 -017
01-018
01-020
04-004
05-004
07-016
11 -009
'•ccupationa I Hazards 08-004
Occupational Noise 02-001
02-005
02-014
04-002
Off ice Design 05-001
Off ice Uoise 04-004
Outboard Motors 00-018
00-019
Physiological effects 00-026
02-001
02-003
02-004
02-007
02-011
157
-------
Physiological Effects (Continued) 02-012
02-013
02-014
02-015
03-003
03-013
03-015
03-020
03-021
Pi le Drivers 01-005
01-025
Plumbing 03-019
07-014
10-009
Pneumatic Equipment 06-005
Poland 02-010
02-013
02-014
03-020
06-004
07-018
11-010
12-006
Preemption 00-027
Product Design 12-002
Propagation 01-007
01-015
Property Value 04-003
04-005
Psychoacoustics 03-006
Psychological Effects 02-001
02-003
02-010
03-006
03-013
03-015
03-017
03-018
03-020
03-021
Public Complaints 01-025
01-026
03-014
03-019
03-022
06-009
08-009
158
-------
Pub I ic Education 12-004
Pub Iic Reaction 00-008
03-022
04-002
Railway Traffic Noise 01-011
03-023
06-004
07-012
Recreational Vehicles 00-017
00-018
00-019
01-023
11-004
Refineries 07-009
Refrigeration Plants 07-017
Refuse Treatment Plant 11-007
Regional Planning 00-013
00-030
Regulations 00-011
00-029
00-031
00-032
00-037
08-004
Residential Noise 00-012
00-033
04-003
04-005
07-003
07-005
07-011
07-013
07-016
07-017
Retrofitting 01-013
07-008
10-002
Road Surface 01-001
11-002
Rock & RolI Music 02-002
02-006
02-008
02-009
Rumania 01-002
159
-------
Schools 00-006
01-004
03-005
11-001
Sensitivity Thresholds 02-005
Sensory Overload 02-008
Sleep Interference 02-007
03-003
03-007
03-008
03-009
03-010
03-011
03-023
Snowmobi Ies 00-017
00-021
01-023
06-003
Sonic Boom 01-007
01-026
02-011
02-016
02-017
03-002
03-003
03-007
03-009
03-011
03-013
12-001
Sonic Boom Carpet 01-007
Sound Absorption 05-002
Sound-Absorptive Materials 01-016
05-001
05-005
Sound Power Level 06-002
Sound Pressure Level 01-012
02-002
02-006
06-002
06-011
Soundproofing 00-033
Soviet Union 01-010
01-011
02-012
160
-------
Soviet Union (Continued) 03-014
03-023
08-004
11-002
Space Fl ights 03-010
Speech Interference 03-001
03-005
06-011
11-004
Standards 00-012
00-016
00-029
02-010
03-016
06-005
06-006
08-003
08-004
08-008
10-008
11-005
1 1-007
12-C
Startle Reactions 02-011
02-016
02-017
Stress Reactions 02-001
02-007
Structures, Effect on 01-026
Subways 00-023
10-010
Supersonic Transport 03-002
10-001
Surveys 00-003
00-026
03-007
03-008
03-012
03-021
03-022
07-018
11-002
11-004
11-010
11-011
Sweden 03-004
05-004
161
-------
Switzerland 09-001
09-004
10-006
Temporary Threshold Shift 01-023
02-006
02-008
06-012
Ti re Noise 01--001
03-012
Tractors 00-001
01-010
Traffic Management 07-007
Traffic Noi se 00-005
00-034
01-002
01-006
01-027
03-004
03-012
03-014
04-004
06-004
06-010
07-005
07-006
07-007
10-009
11-009
11-011
Transportation Noise 00-009
00-010
00-015
00-017
04-003
10-003
10-004
10-010
1 1-002
Truck Noi se 01-001
07-012
07-013
08-002
11-003
Typewriter Noise 11-008
Ultra Sound 00-025
Urban Noi se 01-002
03-008
162
-------
Urban Noise (Continued) 06-010
07-006
07-016
11-002
Urban Planning 00-015
01 -027
06-004
07-001
07-006
07-016
07-018
10-003
Ventilation Systems
Vibration Damping 01-009
Vibration, Structural 01-026
Weighting Scales 06-008
06-012
White Noise 02-017
03-010
Wi I derness Areas 00-018
Wildlife 00-018
02-016
Windows 05-003
Zoning 07-002
08-006
08-007
09-003
11-007
Zurich 09-004
163
-------
Abrol, B. M,
Aizawa, R.
Al len, C. H.
Anderson, G. S.
Angevi ne, 0. L.
Anti caglia, J.
Baade, P. K.
Becker, R.
Bennin, R.
Bergsten, L.
Berzinya, A. K.
Biborosch, L.
Biehn, K.
Birchler, F.
Bobin, Ye. V.
Bonk, U.
Borsky, P. N.
Botsford, J. H.
Brammer, A. J.
Bricken, G.
Brown, L.
Brunt, J.
Rurrow;, A. A.
Burt, M. E.
Bystrzanowska, T.
Caccavari, C.
02-002
03-008
12-007
01-019
07-010
03-017
02 -009
06-012
06-002
06-006
02-004
03-013
00-038
00-001
1 1-002
01-002
11-008
09-004
01-011
02-004
03-015
06-003
12-004
00-035
10-009
01-020
03-022
07-007
02-014
08-011
08-012
Campbe II, R. A.
Caputa, T.
Carpenter, P. L.
Chotecki, B.
Cod I i n , J . B.
Cohen, A.
Cottereau, P.
Cuadra, E.
Den isov, E. i .
Dieh I . G. M.
Doak, P. E.
Dobbs, M. E.
Domanska, M.
Domanski , R.
Doster, M. E.
Dougherty, J .
Downs, M. P.
Dri scol I , J .
Emb leton , T. F.
Erski ne, J . B.
Fosca, V.
F I anagan , W.
Goldshore, L.
Goldstein, S. N.
Goncharenko, V, P.
Gorsh kov, S. I .
1 1 -004
02-014
06-012
02-013
00-003
02- 009
06-012
02-016
08-008
08-004
04-001
06-008
06-009
01-012
03-011
03-020
02-014
02-008
00-026
02-008
00-024
01-008
01-014
01-015
01-020
01-002
01-001
00-029
08-003
01-010
02-003
164
-------
GottemoeI i or, F.
Gregoire, M. C.
Gri mster, W. F.
Hansen, P.
Hasten, J,
Heebink, T. B.
Hemenway , \i. G.
Hixon, E.
Hockey, G. R.
Howe, J . T.
Hurlburt, R. L.
Ivanov, N . I.
J ackson, C. E .
Jackson, E. L.
Jones. H. H.
Jonsson, E
Kaj land, A.
Karagodi na, I . L.
Karlsson, C. G.
Kiessling, P.
Ki hI man, T.
Knight, K, G.
Kohan, N. A.
Kolesn i kova, A. V.
Kozerenko, 0. P.
07-010
01 --01 8
01-017
08--010
00-001
05-002
02-008
01-008
01-014
01-015
00-014
03-018
00-037
04-005
06-007
08-007
10-002
11-003
01-017
00-002
02-009
03-004
03-004
02-012
03-023
02-001
02-004
05-005
002-023
02-003
02-003
03-010
Kraege, R.
Kreml , F. M.
Kryter, K. D.
Kugler, B. A.
Kuitu, H. G.
Kvitka, V.
Lane, S. R.
Lang, W. W.
Langdon , J .
Larimore, H. T.
Laudanski . A.
Lentz, J . L.
Lesser, J .
Lewi s, E .
Li ncol n , R.
Lindberg, Z. Y.
Lorenz, W.
Lukas , J . S .
Lumsden, K. G.
Man, A.
Martin, T.
Matheson, W. K.
Matsui, K.
May, D, N.
McCol I om, H .
McHahon , N. M.
07-004
10-007
00-031
02-007
03-013
01-019
07-008
10-001
07-005
07-013
11-011
12-002
06-013
00-032
02-013
00-030
08-005
08-006
00-006
00-019
11-002
03-001
03- 009
00-036
10-003
00-021
07-015
03-021
01-012
00-025
07-012
165
-------
Men'shov, A. A.
Monaghan, J.
Mori, S.
Mug i kura, K.
Myasn ikov, V. I.
Myles, D. V.
Nagata, Y.
Nakamura, G.
Nath, L. M.
Nekipelov, M. I
Nixon, C. W.
Ny I in, S.
Olpin, 0.
Orski. C. K.
Ostergaard, P. I
Owen, D. A.
Paccagnella, B.
Paik, I. K.
Parrott, C. D.
Pearsons, K. S.
Pinter, I.
Popped, N.
Poza, F.
Priede, T.
Puzyna, C.
Rajchert, W.
Rai ney, J. T.
02-005
00-018
03-005
07-011
03-010
01-008
01-014
01-015
02-015
03-016
02-002
03-014
03-019
03-002
05-004
00-017
00-034
04-002
06-007
03-004
04-003
00-015
06-011
11-001
01-002
03-013
01-006
06-004
12-006
01-003
Rice, C. G.
Richards , E. J .
Ri ngham, R. F.
Rintelmann, W. F.
Rosenberg, C. J .
Rupert, H. M.
Ry lander, R.
Sadowski , J .
Sahai , A. N.
Sakamoto, H.
Salter, C. M.
Schenker-Spruengl i , 0.
Schmidt, H.
Schneider, M.
Schirmer, W.
Schuler, K.
Schultz, T. J.
Scott, W. N.
Seebol d, J . G.
Semczuk, B.
S i epmann, J .
Si nger, A . A.
Skorodumov, G. Ye.
Smith, W. A.
Smitley, E. K.
Soldatkina, S. A.
Spahr, H.
Spano, B.
03-007
03-003
00-010
02-006
01-005
00-009
03-003
12-001
07-018
02-002
03-021
01-005
09-001
10-006
07-002
08-001
11-008
10-010
07-012
03-012
07-014
03-020
07-017
00-033
11-003
09-002
02-006
02-012
00-008
00-012
166
-------
Sp i echowi cz, S.
Staadt, R. L.
Stacy, E. F.
Stand I ey, D.
Stan i os W.
Stephens, S. D.
Streckenbach, J . M.
Sulewsky, J . E.
Sulkowski, W.
Sutton, A.
Sutton, P.
Tanner, C.
Thackray, R. I.
Thomas R. J.
Toole, F. E.
Townend, D. S.
Tsysar, A. I.
V i nokur, I. L.
Vargovick, R. J.
Von Gierke, H, E.
VuIka, G. H.
WaIk, F. H.
Walker, B.
Warren, C. H.
Warren, D. G.
Watts, J. A.
Weber, H.
Vtegner, R. L.
W i I I i ams, C. E.
02-010 Wiedefeld, J.
00-010 Wojtowicz, P.
07-003 Yakovleva, I . Ya.
00-027 Verges, L. F.
03-020 Yoerger, R.
03-006 Yoshikai , K.
01-018 Young, J . R.
05-001 Zagurskaya, L. A.
02-013 Zamarin, D. M.
00-028 Zel ler, W.
08-009 Zimmerman, M. D.
00-016
02-011
04-004
12-004
07-009
03-023
02-012
11-009
03-002
07-016
00-004
00-011
01-007
09-003
00-005
00-022
00-013
06-011
01-004
11-010
03-010
05-003
00-020
03-008
11-006
02-005
03-022
07-017
12-005
167
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GLOSSARY
The following explanations of terms are provided to assist the reader in
understanding some terms used in this publication:
A-WEIGHTED SOUND LEVEL -- The ear does not respond equally to
frequencies, but is less efficient at low and high frequencies than it
is at medium or speech range frequencies. Thus, to obtain a single
number representing the sound level of a noise containing a wide
range of frequencies in a manner representative of the ear's
response, it is necessary to reduce, or weight, the effects of the
low and high frequencies with respect to the medium frequencies.
The resultant sound level is said to be A-weighted, and the units are
dB. A popular method of indicating the units, dBA, is used in this
Digest. The A-weighted sound level is also called the noise level.
Sound level meters have an A-weighting network for measuring
A-weighted sound level.
ABSORPTION -- Absorption is a property of materials that reduces the
amount of sound energy reflected. Thus, the introduction of an
"absorbent" into the surfaces of a room will reduce the sound
pressure level in that room by virtue of the fact that sound energy
striking the room surfaces will not be totally reflected. It should
be mentioned that this is an entirely different process from that of
transmission loss through a material, which determines how much
sound gets into the room via the walls, ceiling, and floor. The
effect of absorption merely reduces the resultant sound level in
the room produced by energy which has already entered the room.
ABSORPTION COEFFICIENT -- A measure of sound-absorbing ability
of a surface. This coefficient is defined as the fraction of incident
sound energy absorbed or otherwise not reflected by the surface.
Unless otherwise specified, a diffuse sound field is assumed. The
values of sound-absorption coefficient usually range from about
0. 01 for marble slate to almost 1. 0 for long absorbing wedges such as
are used in anechoic chambers.
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HARMONIC -- A sinusoidal (pure-tone) component whose frequency
is a whole-number multiple of the fundamental frequency of the
wave. If a component has a frequency twice that of the funda-
mental it is called the second harmonic.
HEARING DISABILITY -- An actual or presumed inability, due to
hearing impairment, to remain employed at full wages.
HEARING HANDICAP -- The disadvantage imposed by a hearing
impairment sufficient to affect one's efficiency in the situation
of everyday living.
HEARING IMPAIRMENT -- A deviation or change for the worse in
either hearing structure or function, usually outside the normal
range; see hearing loss.
HEARING LOSS -- At a specified frequency, an amount, in decibels,
by which the threshold of audibility for that ear exceeds a certain
specified audiometric threshold, that is to say, the amount by
which a person's hearing is worse than some selected norm.
The norm may be the threshold established at some earlier time
for that ear, or the average threshold for some large population,
or the threshold selected by some standards body for autiometric
measurements.
HEARING LOSS FOR SPEECH -- The difference in decibels between
the speech levels at which the "average normal" ear and a defec-
tive ear, respectively, reach the same intelligibility, often
arbitrarily set at 50%.
HERTZ -- Unit of measurement of frequency, numerically equal
to cycles per second.
IMPACT -- (1) An impact is a single collision of one mass in motion
-with a second mass -which may be either in motion or at rest.
(Z) Impact is a word used to express the extent or severity of an
environmental problem; e. g. , the riumber of persons exposed to
a given noise environment.
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ACCELEROMETER (ACCELERATION PICKUP) - - An electroacoustic
transducer that responds to the acceleration of the surface to which
the transducer is attached, and delivers essentially equivalent elec-
tric waves.
ACOUSTICAL POWER -- See sound power.
ACOUSTICS -- (1) The science of sound, including the generation,
transmission, and effects of sound waves, both audible and inaudible.
(2) The physical qualities of a room or other enclosure(such as
size, shape, amount of sound absorption, and amount of noise)
which determine the audibility and perception of speech and music.
AIRBORNE SOUND -- Sound that reaches the point of interest by
propagation through air.
AIR FLOW RESISTANCE -- See flow resistance.
AMBIENT NOISE LEVEL -- The ambient noise level follows the usage
of the word "ambient" throughout the environmental sciences
(except acoustics). That is, the ambient noise level is that level
which exists at any instant, regardless of source.
ANALYSIS -- The analysis of a noise generally refers to the exami-
nation composition of the noise in its various frequency bands,
such as octaves or third-octaves bands.
ANECHOIC ROOM -- An anechoic room is one whose boundaries have
been designed (with acoustically absorbent materials) to absorb
nearly all the sound incident on its boundaries, thereby affording
a test room essentially free from reflected sound.
ANTINODE (LOOP) -- A point, line, or surface in a standing wave
where the vibration or sound pressure has maximum amplitude.
ARTICULATION INDEX (AI) -- A numerically calculated measure of
the intelligibility of transmitted or processed speech. It takes into
account the limitations of the transmission path and the background
noise. The articulation index can range in magnitude between 0
and 1. 0. If the AI is less than 0. 1, speech intelligibility is
generally low. If it is above 0. 6, speech intelligibility is generally
high.
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AUDIO FREQUENCY -- The frequency of oscillation of an audible
sine-wave of sound; any frequency between 20 and 20, 000 Hz.
See also frequency.
AURAL -- Of or pertaining to the ear or hearing.
AUDIOGRAM -- A graph showing hearing loss as a function of
frequency.
AUDIOMETER -- An instrument for measuring hearing sensitivity of
hearing loss.
BACKGROUND NOISE -- The total of all noise in a system or situation,
independent of the presence of the desired signal. In acoustical
measurements, strictly speaking, the term "background noise"
means electrical noise in the measurement system. However, in
popular usage the term "background noise" is also used with the
same meaning as "residual noise. "
BAFFLE -- A baffle is a shielding structure or series of partitions used
to increase the effective length of the external transmission path
between two points in an acoustic system. For example, baffles
may be used in sound traps (as in air conditioning ducts) or in
automotive mufflers to decrease the sound transmitted while
affording a path for air flow.
BAND -- A segment of the frequency spectrum.
BAND CENTER FREQUENCY -- The designated (geometric) mean
frequency of a band of noise or other signal. For example, 1000 Hz
is the band center frequency for the octave band that extends from
707 Hz to 1414 Hz, or for the third-octave band that extends from
891 Hz to 1123 Hz.
BAND PRESSURE (OR POWER) LEVEL -- The pressure (or power)
level for the sound contained within a specified frequency band.
The band may be specified either by its lower and upper cut-off
frequencies, or by its geometric center frequency. The width of
the band is often indicated by a prefatory modifier; e. g. , octave
band, third-octave band, 10-Hz band.
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BOOM CARPET -- The area on the ground underneath an aircraft
flying at supersonic speeds that is hit by a sonic boom of specified
magnitude.
BROADBAND NOISE -- Noise with components over a wide range of
frequencies.
C-WEIGHTED SOUND LEVEL (dBC) -- A quantity, in decibels, read
from a standard sound-level meter that is switched to the weighting
network labeled "C". The C-weighting network weights the fre-
quencies between 70 Hz and 4000 Hz uniformly, but below and above
these limits frequencies are slightly discriminated against.
Generally, C-weighted measurements are essentially the same as
overall sound-pressure levels, which require no discrimination at
any frequency.
COINCIDENCE EFFECT -- The coincidence effect occurs when the
wavelength of the bending wave in a panel coincides with the length
of an incident sound wave at the angle at -which it strikes the panel.
At any particular frequency, this effect can occur only if the wave
in air is traveling at a particular angle with respect to the surface
of the panel. Under this condition a high degree of coupling is
achieved between the bending wave in the panel and the sound in the
air. When the coincidence effect occurs, the transmission loss
for the panel is greatly reduced. See also critical frequency.
COMMUNITY NOISE EQUIVALENT LEVEL -- Community Noise
Equivalent Level (CNEL) is a scale which takes account of all the
A-weighted acoustic energy received at a point, from all noise
events causing noise levels above some prescribed value. Weighting
factors are included which place greater importance upon noise
events occurring during the evening hours (7:00 p.m. to 10:00 p.m.)
and even greater importance upon noise events at night (10:00 p.m.
to 6:00 a. m. ).
COMPOSITE NOISE RATING -- Composite noise rating (CNR) is a
scale which takes account of the totality of all aircraft operations at
an airport in quantifying the total aircraft noise environment. It
was the earliest method for evaluating compatible land use around
airports and is still in wide use by the Department of Defense in
predicting noise environments around military airfields.
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COMPOSITE NOISE RATING -- (Cont'd)
Basically, to calculate a CNR value one begins with a measure of
the maximum noise magnitude from each aircraft flyby and adds
weighting factors which sum the cumulative effect of all flights.
The scale used to describe individual noise events is perceived
noise level (in PNdB); the term accounting for number of flights
is 10 log-^gN (where N is the number of flight operations), and
each night operation counts as much as 10 daytime operations.
Very approximately, the noise exposure level at a point expressed
in the CNR scale will be numerically 35-37 dB higher than if
expressed in the CNEL scale.
CONTINUOUS SOUND SPECTRUM -- A continuous sound spectrum is
comprised of components which are continuously distributed over
a frequency region.
CRITERION -- A criterion, in Federal environmental usage, is a state-
ment of the cause and effect relationship between a given level of
pollutant and specific effects on human life.
CRITICAL FREQUENCY -- The critical frequency is the lowest
frequency at which the coincidence effect can occur. At this
frequency the coincidence angle is 90 , that is, the sound wave
is traveling parallel to the surface of the panel. Below this
frequency, the wavelength in air is greater than the bending wave-
length in the panel.
CUTOFF FREQUENCIES -- The frequencies that mark the ends of a
band, or at which the characteristics of a filter change from pass
to no-pass.
CYLINDRICAL DIVERGENCE -- Cylindrical divergence is the condi-
tion of propagation of cylindrical waves that accounts for the
regular decrease in intensity of a cylindrical wave at progressively
greater distances from the source. Under this condition the sound-
pressure level decreases 3 decibels with each doubling of distance
from the source. See also spherical divergence.
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CYLINDRICAL, WAVE -- A cylindrical wave is a wave in which the
surfaces of constant phase are coaxial cylinders. A line of closely
spaced sound sources radiating into an open space produces a free
sound field of cylindrical waves. See also cylindrical divergence.
CYCLES PER SECOND -- A measure of frequency numerically
equivalent to Hertz.
DAMAGE RISK CRITERION -- A statement of noise levels (including
frequency, duration, intermittancy, and other factors) above which
permanent hearing loss of at least a specified amount is likely to
be sustained by a person (to a given degree of probability). See
also hearing loss, criterion.
DAMPING -- The dissipation of energy with time or distance. The
term is generally applied to the attenuation of sound in a structure
owing to the internal sound-dissipative properties of the structure
or owing to the addition of sound-dissipative materials.
DECIBEL -- The decibel (abbreviated "dB") is a measure, on a logari-
thmic scale, of the magnitude of a particular quantity (such as sound
pressure, sound power, intensity, etc.) with respect to a standard
reference value. (0.0002 microbars for sound pressure and 10
•watt for sound power).
DIFFUSE SOUND FIELD -- The presence of many reflected waves
(echoes) in a room (or auditorium) having a very small amount
of sound absorption, arising from repeated reflections of sound
in various directions. In a diffuse field, the sound pressure level,
averaged over time, is everywhere the same and the flow of sound
energy is equally probable in all directions.
DIRECTIVITY INDEX -- In a given direction from a sound source, the
difference in decibels between (a) the sound-pressure level produced
by the source in that direction, and (b) the space-average sound-
pressure level of that source, measured at the same distance.
DIRECTIVITY PATTERN -- The directivity pattern of a source of sound
is the hypothetical surface in space over which the sound pressure
levels produced by the source are constant. See also directivity
index.
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DOPPLER EFFECT ( DOPPLER SHIFT) -- The apparent upward
shift in frequency of a sound as a noise source approaches the
listener (or vice versa), and the apparent downward shift when
the noise source recedes. The classic example is the change in
pitch of a railroad whistle as the locomotive approaches and
passes by.
DUCT LINING OR WRAPPING -- Usually a sheet of porous material
placed on the inner or outer wall(s) of a duct to introduce sound
attenuation and heat insulation. It is often used in air conditioning
systems. Linings are more effective in attenuating sound that
travels inside along the length of a duct, while wrappings are more
effective in preventing sound from being radiated from the duct
sidewalls into surrounding spaces.
EFFECTIVE PERCEIVED NOISE LEVEL (EPNL) -- A physical
measure designed to estimate the effective "noisiness" of a single
noise event, usually an aircraft fly-over; it is derived from instan-
taneous Perceived Noise Level (PNL) values by applying correc-
tions for pure tones and for the duration of the noise.
ELECTROACOUSTICS -- The science and technology of transforming
sound waves into currents in electrical circuits (and vice versa), by
means of microphones, loudspeake-rs, and electronic amplifiers
and filters.
FAR FIELD -- Consider any sound source in free space. At a
sufficient distance from the source, the sound pressure level obeys
the inverse-square law (the sound pressure decreases 6 dB with
each doubling of distance from the source). Also, the sound parti-
cle velocity is in phase with the sound pressure. This region is
called the far field of the sound source. Regions closer to the
source, where these two conditions do not hold, constitute the
near field. In an enclosure, as opposed to free space, there can
also sometimes be a far field region if there is not so much
reflected sound that the near field and the reverberant field
merge. See also reverberant field.
FILTER -- A device that transmits certain frequency components of
the signal (sound or electrical) incident upon it, and rejects other
frequency components of the incident signal.
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FLOW RESISTANCE -- The flow resistance of a porous material is
one of the most important quantities determining the sound absorb-
ing characteristics of the material. Flow resistance is a ratio of
the pressure differential across a sample of the porous material
to the air velocity through it.
FOOTPRINT (NOISE) -- The shape and size of the geographical
pattern of noise impact that an aircraft makes on the areas near
an airport while landing or taking off.
FREE SOUND FIELD (FREE FIELD) -- A sound field in which the
effects of obstacles or boundaries on sound propagated in that
field are negligible.
FREQUENCY -- The number of times per second that the sine-wave
of sound repeats itself, or that the sine-wave of a vibrating object
repeats itself. Now expressed in Hertz(Hz), formerly in cycles
per second (cps).
FUNCTION -- A quantity which varies as a result of variations of
another quantity.
FUNDAMENTAL FREQUENCY -- The frequency with which a
periodic function reproduces itself, sometimes called the first
harmonic, (see also harmonic).
GAUSSIAN DISTRIBUTION (Or NORMAL DISTRIBUTION) -- A term
used in statistics to describe the extent and frequency of deviations
or errors. The outstanding characteristics are a tendency to a
maximum number of occurrences at or near the center or mean
point, the progressive decrease of frequency of occurrence with
distance from the center, and the symmetry of distribution on
either side of the center. In respect of random noise, each
fluctuation of amplitude is an occurrence, whether above or
below the mean level; the peak value of each fluctuation is the
error and the distribution of errors with time is Gaussian.
GRADIENT -- A variation of the local speed of sound with height
above ground or other measure of distance causing refraction of
sound. It is most commonly caused by rising or falling temperature
with altitude or by differences in wind speed.
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IMPACT INSULATION CLASS (IIC) -- A single-figure rating which
is intended to permit the comparison of the impact sound insula-
ting merits of floor-ceiling assemblies in terras of a reference
contour.
IMPACT SOUND -- The sound arising from the impact of a solid
object on an interior surface (wall, floor, or ceiling) of a building.
Typical sources are footsteps, dropped objects, etc.
INFRASONIC -- Of a frequency below the audio frequency range.
INVERSE-SQUARE LAW -- The inverse-square law describes that
acoustic situation where the mean-square pressure changes in
inverse proportion to the square of the distance from the source.
Under this condition the sound-pressure level decreases 6 deci-
bels with each doubling of distance from the source. See also
spherical divergence.
ISOLATION -- See vibration isolator.
JET NOISE -- Noise produced by the exhaust of a jet into its surround-
ing atmosphere. It is generally associated with the turbulence
generated along the interface between the jet stream and the
atmosphere.
L-JQ LEVEL -- The sound level exceeded 10% of the time. Corres-
ponds to peaks of noise in the time history of environmental noise
in a particular setting.
LSO LEVEL -- The sound level exceeded 50% of the time.
Corresponds to the average level of noise in a particular setting,
over time.
L9Q LEVEL -- The sound level exceeded 90% of the time.
Corresponds to the residual noise level.
LEVEL -- The value of a quantity in decibels. The level of an
acoustical quantity (sound pressure or sound power), in decibels,
is 10 times the logarithm (base 10) of the ratio of the quantity to
a reference quantity of the same physical kind.
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LINE SPECTRUM -- The spectrum of a sound whose components occur
at a number of discrete frequencies.
LIVE ROOM -- One characterized by an unusually small amount of
sound absorption. See reverberation room.
LOUDNESS -- The judgment of intensity of a sound by a human being.
Loudness depends primarily upon the sound pressure of the stimulus.
Over much of the loudness range it takes about a threefold increase
in sound pressure (approx. 10 dB) to produce a doubling of loudness.
LOUDNESS LEVEL -- The loudness level of a sound, in phons, is
numerically equal to the median sound pressure level, in decibels,
relative to 0. 0002 microbar, of a free progressive wave of fre-
quency 1000 Hz presented to listeners facing the source, which
in a number of trials is judged by the listeners to be equally loud.
MACH NUMBER -- The ratio of a speed of a moving element to the
speed of sound in the surrounding medium.
MASKING -- The action of bringing one sound (audible when heard
alone) to inaudibility or to unintelligibility by the introduction of
another sound. It is most marked when the masked sound is of
higher frequency than the masking sound.
MASKING NOISE -- A noise which is intense enough to render
inaudible or unintellibilible another sound which is simultaneously
present.
MEAN FREE PATH -- The average distance sound travels between
successive reflections in a room.
MEDIUM -- A substance carrying a sound wave.
MICROBAR -- A microbar is a unit of pressure, equal to one dyne
per square centimeter.
MICROPHONE -- An electroacoustic transducer that responds to
sound waves and delivers essentially equivalent electric waves.
NEAR FIELD -- See far field.
NODE -- A point, line, or surface where a wave has zero amplitude.
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NOISE -- Any sound •which is undesirable because it interferes wit]
speech and hearing, or is intense enough to damage hearing, o:r
is otherwise annoying.
NOISE CRITERION (NC) CURVES -- Any of several versions
(SC, NC, NCA, PNC) of criteria used for rating the accepta-
bility of continuous indoor noise levels, such as produced by
air-handling systems.
NOISE EXPOSURE FORECAST -- Noise exposure forecast (NEF) is a
scale (analogous to CNEL and CNR) which has been used by the
federal government in land use planning guides for use in con-
nection with airports.
In the NEF scale, the basic measure of magnitude for individual
noise events is the effective perceived noise level (EPNL), in
units of EPNdB. This magnitude measure includes the effect of
duration per event. The terms accounting for number of flights
and for weighting by time period are the same as in the CNR
scale. Very approximately, the noise exposure level at a point
expressed in the NEF scale will be numerically about 33 dB
lower than if expressed in the CNEL scale.
NOISE INSULATION -- See sound insulation.
NOISE ISOLATION CLASS (NIC) -- A single number rating derived in
a prescribed manner from the measured values of noise reduction.
It provides an evaluation of the sound isolation between two enclosed
spaces that are acoustically connected by one or more paths.
NOISE LEVEL -- See sound level.
NOISE AND NUMBER INDEX (NNI) -- A measure based on Per-
ceived Noise Level, and with weighting factors' added to account
for the number of noise events, and used (in some European
countries) for rating the noise environment near airports.
NOISE POLLUTION LEVEL (LNp or NPL) -- A measure of the
total community noise, postulated to be applicable to both traffic
noise and aircraft noise. It is computed from the "energy
average" of the noise level and the standard deviation of the
time-varying noise level.
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NOISE REDUCTION (NR) -- The noise reduction between two areas or
rooms is the numerical difference, in decibels, of the average sound
pressure levels in those areas or rooms. A measurement of "noise
reduction" combines the effect of the transmission loss performance
of structures separating the two areas or rooms, plus the effect of
acoustic absorption present in the receiving room.
NOISE REDUCTION COEFFICIENT (NRC) -- A measure of the acous-
tical absorption performance of a material, calculated by the aver-
aging its sound absorption coefficients at 250, 500, 1000, and 2000
Hz, expressed to the nearest integral multiple of 0. 05.
NORMAL, DISTRIBUTION -- See Gaussian distribution.
NOYS -- A unit used in the calculation of perceived noise level.
OCTAVE -- An octave is the interval between two sounds having a
basic frequency ratio of two. For example, there are 8 octaves
on the keyboard of a standard piano.
OCTAVE BAND -- All of the components, in a sound spectrum, whose
frequencies are between two sine wave components separated by an
octave.
OCTAVE-BAND SOUND PRESSURE LEVEL -- The integrated sound
pressure level of only those sine-wave components in a specified
octave band, for a noise or sound having a wide spectrum.
OSCILLATION -- The variation with time, alternately increasing and
decreasing, (a) of some feature of an audible sound, such as the
sound pressure, or (b) of some feature of a vibrating solid object,
such as the displacement of its surface.
PARTIAL NODE -- A partial node is the point, line, or surface in a
standing wave system where there is a minimum amplitude differ-
ing from zero.
PEAK SOUND PRESSURE -- The maximum instantaneous sound
pressure (a) for a transient or impulsive sound of short duration,
or (b) in a specified time interval for a sound of long duration.
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PERCEIVED NOISE LEVEL, (PNL) -- A quantity expressed in deci-
bels that provides a subjective assessment of the perceived
"noisiness" of aircraft noise. The units of Perceived Noise Level
are Perceived Noise Decibels, PNdB.
PERIOD -- The duration of time it takes for a periodic wave form
(like a sine wave) to repeat itself.
PERMANENT THRESHOLD SHIFT (PTS) -- See temporary threshold
shift.
PHASE -- For a particular value of the independent variable, the
fractional part of a period through which the independent variable
has advanced, measured from an arbitrary reference.
PHON -- The unit of measurement for loudness level.
Phon = 40 + Io sone.
PINK NOISE -- Noise where level decreases with increasing
frequency to yield constant energy per octave of band width.
PITCH -- A listener's perception of the frequency of a pure tone; the
higher the frequency, the higher the pitch.
PLANE WAVE -- A wave whose wave fronts are parallel and perpen-
dicular to the direction in which the wave is travelling.
PNdB -- See perceived noise level.
PRESBYCUSIS -- The decline in hearing acuity that normally occurs as
a person grows older.
PURE TONE -- A sound wave whose waveform is that of a sine -wave.
RANDOM INCIDENCE -- If an object is in a diffuse sound field, the
sound waves that comprise the sound field are said to strike the
object from all angles of incidence at random. See also Gaussian
distribution.
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RANDOM NOISE -- An oscillation whose instantaneous magnitude is not
specified for any given instant of time. It can be described in a
statistical sense by probability distribution functions giving the
fraction of the total time that the magnitude of the noise lies within
a specified range.
RATE OF DECAY -- Rate of decay is the time rate at which the sound-
pressure level (or other stated characteristic, such as a vibra-
tion level) decreases at a given point and at a given time after
the source is turned off. The commonly used unit is decibels per
second.
REFRACTION -- The bending of a sound wave from its original path,
either because it is passing from one medium to another or because
(in air) of a temperature or wind gradient in the medium.
RESIDUAL NOISE LEVEL -- The term "residual noise" has been
adopted to mean the noise which exists at a point as a result of
the combination of many distant sources, individually indistin-
guishable. In statistical terms, it is the level which exists
90 percent of the time. (Acousticians should note it means the
same level to which they have customarily applied the term
"ambient. ") See also background noise.
RESONANCE -- The relatively large amplitude of vibration produced
when the frequency of some source of sound or vibration "matches"
or synchronizes with the natural frequency of vibration of some
object, component, or system.
RESONATOR -- A resonator is a device that resounds or vibrates in
sympathy with some source of sound or vibration.
RETROFIT -- The retroactive modification of an existing building or
machine. In current usage, the most common application of the
word "retrofit" is to the question of modification of existing jet
aircraft engines for noise abatement purposes.
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REVERBERANT FIELD -- The region in a room where the reflected
sound dominates, as opposed to the region close to the noise
source where the direct sound dominates.
REVERBERATION -- The persistence of sound in an enclosed space,
as a result of multiple reflections, after the sound source has
stopped.
REVERBERATION ROOM -- A room having a long reverberation
time, especially designed to make the sound field inside it as
diffuse (homogeneous) as possible. Also called a live room.
REVERBERATION TIME (RT) -- The reverberation time of a room
is the time taken for the sound pressure level (or sound intensity)
to decrease to one-millionth (60 dB) of its steady state value
when the source of sound energy is suddenly interrupted. It is a
measure of the persistence of an impulsive sound in a room and
of the amount of acoustical absorption present inside the room.
ROOM CONSTANT -- The room constant is equal to (a) the product
of the average absorption coefficient of the room and the total
internal area of the room, divided by (b) the quantity one minus
the average absorption coefficient.
ROOT-MEAN-SQUARE (RMS) -- The root-mean square value of a
quantity that is varying as a function of time is obtained by
squaring the function at each instant, obtaining the average of
the squared values over the interval of interest, and taking the
square root of this average. For a sine wave, multiply the
RMS value by -\j 2 , or about 1.43, to get the peak value of the
wave. The RMS value, also called the effective value of the
sound pressure, is the best measure of ordinary continuous
sound, but the peak value is necessary for assessment of
impulse noises.
SHIELDING -- The attenuation of a sound by placing walls, build-
ings, or other barriers between a sound source and the receiver.
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SINE-WAVE -- A soundwave, audible as a pure tone, in which the
sound pressure is a sinusoidal function of time .
SONE -- The unit of measurement for loudness. One sone is the
loudness of a sound whose level is 40 phons.
SONIC BOOM -- The pressure transient produced at an observing
point by a vehicle that is moving past (or over) it faster than the
speed of sound.
SOUND -- See acoustics (1).
SOUND ABSORPTION COEFFICIENT -- See absorption coefficient.
SOUND ANALYZER -- A sound analyzer is a device for measuring the
band pressure level or pressure-spectrum level of a sound as a
function of frequency.
SOUND INSULATION -- (1) The use of structures and materials
designed to reduce the transmission of sound from one room or
area to another or from the exterior to the interior of a building.
(2) The degree by which sound transmission is reduced by means
of sound insulating structures and materials.
SOUND LEVEL (NOISE LEVEL) -- The weighted sound pressure level
obtained by use of a sound level meter having a standard frequency-
filter for attenuating part of the sound spectrum.
SOUND LEVEL METER -- An instrument, comprising a microphone,
an amplifier, an output meter, and frequency-weighting networks,
that is used for the measurement of noise and sound levels in a
specified manner.
SOUND POWER -- Of a source of sound, the total amount of acoustical
energy radiated into the atmospheric air per unit time.
SOUND POWER LEVEL -- The level of sound power, averaged over a
period of time, the reference being 10- watts.
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SOUND PRESSURE -- (1) The minute fluctuations in atmospheric
pressure which accompany the passage of a sound wave; the
pressure fluctuations on the tympanic membrane are transmitted
to the inner ear and give rise to the sensation of audible sound.
(2) For a steady sound, the value of the sound pressure averaged
over a period of time. (3) Sound pressure is usually measured
(a) in dynes per square centimeter (dyn/cm ), or (b) in newtons
per square meter (N/m ). 1 N/m = 10 dyn/cm 10- times
the atmospheric pressure.
SOUND PRESSURE LEVEL -- The root-mean-square value of the
pressure fluctuations above and below atmospheric pressure
due to a sound wave; expressed in decibels re a reference
pressure of 0.0002 microbars (2 x 10~5 Newtons per square
meter).
SOUND SHADOW -- The acoustical equivalent of a light shadow. A
sound shadow is often partial because of diffraction effects.
SOUND TRANSMISSION CLASS (STC) -- The preferred single figure
rating system designed to give an estimate of the sound insulation
properties of a partition or a rank ordering of a series of partitions.
It is intended for use primarily when speech and office noise con-
stitute the principal noise problem.
SOUND TRANSMISSION COEFFICIENT -- The fraction of incident sound
energy transmitted through a structural configuration.
SOUND TRANSMISSION LOSS (TRANSMISSION LOSS) (TL) -- A
measure of sound insulation provided by a structural configuration.
Expressed in decibels, it is 10 times the logarithm to the base 10
of the reciprocal of the sound transmission coefficient of the con-
figuration.
SPACE-AVERAGE SOUND PRESSURE LEVEL -- ' The space-average
sound-pressure level is the sound pressure level averaged over
all directions at a constant distance from the source.
SPECTRUM -- Of a soundwave, the description of its resolution into
components, each of different frequency and (usually) different
amplitude and phase.
185
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SPEECH-INTERFERENCE LEVEL (SIL) -- A calculated quantity
providing a guide to the interfering effect of a noise on reception
of speech communication. The speech-interference level is the
arithmetic average of the octave-band sound-pressure levels of
the interfering noise in the most important part of the speech
frequency range. The levels in the three octave-frequency bands
centered at 500, 1000, and ZOOO Hz are commonly averaged to
determine the speech-interference level. Numerically, the
magnitudes of aircraft sounds in the Speech-Interference Level
scale are approximately 18 to 22 dB less than the same sounds in
the Perceived Noise Level scale in PNdB, depending on the
spectrum of the sound.
SPEED (VELOCITY) OF SOUND IN AIR -- The speed of sound in air is
344 m/sec or 1128 ft/sec at 78°F.
SPHERICAL DIVERGENCE -- Spherical divergence is the condition of
propagation of spherical waves that relates to the regular decrease
in intensity of a spherical sound wave at progressively greater
distances from the source. Under this condition the sound-
pressure level decreases 6 decibels with each doubling of dis-
tance from the source. See also cylindrical divergence.
SPHERICAL WAVE -- A sound wave in which the surfaces of constant
phase are concentric spheres. A small (point) source radiating
into an open space produces a free sound field of spherical waves.
SPL -- See sound pressure level.
STANDARD -- (1) A prescribed method of measuring acoustical
quantitites. Standards in this sense are promulgated by
professional and scientific societies like ANSI, SAE, ISO, etc. ,
as well as by other groups. (2) In the sense used in Federal
environmental statutes, a standard is a specific statement of
permitted environmental conditions.
STANDING WAVE -- A periodic sound wave having a fixed distribution
in space, the result of interference of traveling sound waves of
the same frequency and kind. Such sound waves are character-
ized by the existence of nodes, or partial nodes, and antinodes
that are fixed in space.
186
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STEADY-STATE SOUNDS -- Sounds whose average characteristics
remain constant in time. An example of a steady-state sound is
an air conditioning unit.
STRUCTUREBORNE SOUND -- Sound that reaches the point of interest,
over at least part of its path, by vibration of a solid structure.
SUBHARMONIC -- A sound component of frequency a whole-number of
times less than the fundamental frequency of the sounds' complex
wave.
TAPPING MACHINE -- A device that produces a standard impulsive
noise by letting weights drop a fixed distance onto the floor.
Used in tests measuring the isolation from impact noise provided
by various floor-ceiling constructions.
TEMPORARY THRESHOLD SHIFT (TTS) -- A temporary impairment
of hearing capability as indicated by an increase in the threshold
of audibility. By definition, the ear recovers after a given period
of time. Sufficient exposures to noise of sufficient intensity,
from which the ear never completely recovers, will lead to
a permanent threshold shift (PTS), which constitutes hearing
loss. See hearing loss, threshold shift, threshold of audibility.
THIRD-OCTAVE BAND -- A frequency band whose cut-off frequencies
have a ratio of 2 to the one-third power, which is approximately
1. 26. The cut-off frequencies of 891 Hz and 1112 Hz define a
third-octave band in common use. See also band center frequency.
THRESHOLD OF AUDIBILITY (THRESHOLD OF DETECTABILITY) --
The minimum sound-pressure level at which a person can hear
a specified sound for a specified fraction of trials.
THRESHOLD SHIFT --An increase in a hearing threshold level that
results from exposure to noise.
TONE -- A sound of definite pitch. A pure tone has a sinusoidal
wave form.
TRAFFIC NOISE INDEX (TNI) -- A measure of the noise environment
created by vehicular traffic on highways; it is computed from
measured values of the noise levels exceeded 10 percent and
90 percent of the time.
187
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TRANSMISSION LOSS -- See sound transmission loss.
TRANSDUCER -- A device capable of being actuated by waves from one
or more transmission systems or media and supplying related
waves to one or more other transmission systems or media.
Examples are microphones, accelerometers, and loudspeakers.
TTS -- See temporary threshold shift
ULTRASONIC -- Pertaining to sound frequencies above the audible
sound spectrum (in general, higher than 20, 000 Hz).
VIBRATION ISOLATOR -- A resilient support for machinery and other
equipment that might be a source of vibration, designed to reduce
the amount of vibration transmitted to the building structure.
WAVEFORM -- A presentation of some feature of a sound wave, e. g. ,
the sound pressure, as a graph showing the moment-by-moment
variation of sound pressure with time.
WAVEFRONT -- An imaginary surface of a sound wave on its way
through the atmosphere. At all points on the wavefront, the wave
is of equal amplitude and phase.
WAVELENGTH -- For a periodic wave (such as sound in air), the
perpendicular distance between analogous points on any two
successive waves. The wavelength of sound in air or in water
is inversely proportional to the frequency of the sound. Thus
the lower the frequency, the longer the wavelength.
WHITE NOISE -- Noise whose energy is uniform over a wide range of
frequencies, being analogous in spectrum characteristics to
white light. White noise has a "hishing" sound. See also
broadband noise.
WRAPPING -- See duct lining or wrapping.
188
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ABBREVIATIONS
AAT Auditory Awakening Threshold
ADIZ Audible Noise Sensitive Warning
Al Acceptability Index
Al Articulation Index
APNL Average Peak Noise Level
BS British Standards
CDR Composite Damage Risk
CL Comfort Level
CNEL Community Noise Equivalent Level
CNR Composite Noise Rating
CPNL Continuous Perceived Noise Level
DIN German Industrial Norm (Deutsche Industrie Norm)
DME Distance Measuring Equipment
DRC Damage Risk Contours
ECPNL Equivalent Continuous Perceived Noise Level
EDRL Effective Perceived Noise Level
EEC Electroencephalogram
EMC Electromyogram
ENG Electronystagmograph
EN I Environmental Noise Index
EPNDB Effective Perceived Noise
FSTC Field Sound Transmission Class
GNL General Noise Level
HL Hearing Level
HNL Hourly Noise Level
Hz Hertz
ICE Internal Combustion Engine
IDL Intelligibility Disturbance Level
189
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ILS Instrument Landing System
INR Impact Noise Rating
IPNL Integrated Perceived Noise Level Loudness Level
LL Loudness Level
LOA Level of Optimum Articulation
MAT Minimal Aversion Threshold
MEL Mean Energy Level
MPL Multiple Pure Tones
MAC Noise Abatement Climb
NC Noi se Criterion
NIC Noise Isolation Class
NIPTS Noise-Induced Permanent Threshold Shift
NNI Noise Number Index
NPL Noise Pollution Level
NR Noise Rating
NRC Noise Reduction Coefficient
PNDB Perceived Noise
PNL Perceived Noise Level
PSD Power Spectral Density
PSF Comparison Peak Overpressure
PTS Permanent Threshold Shift
PWL Sound Power Level
RECAT Regulatory Effects on the Costs of Automative
Transportation
RE I L Runway End Indicator Lights
REM Rapid Eye Movement
RMS Root Mean Square
ROPS RoI I-over Protective Structures
RRL Road Research Laboratory
190
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RT
SAE
SENEL
SFC
S!L
SIN
SPL
SST
STC
STL
STOL
TACV
TL
TLV
TNI
TPU
TTS
UAN
VASI
VTOL
V/STOL
WECPNL
Reverberation Time
Statistical Energy Analysis
Single Event Noise Exposure Level
Space Flight Center
Speech Interference Level
Spatially Incoherent Noise
Sound Pressure Level
Supersonic Transport
Sound Transmission Class
Sound Transmission Loss
Short Take-off and Landing
Tracked Air Cushion Vehicles
Transmission Loss
Threshold Limit Value
Traffic Noise Index
Transmission Preference Unit
Temporary Threshold Shift
Useful Auditory Area in Noise
Visual Approach Slope Indicator
Vertical Take-off and Landing
Vertical Short Take-off and Landing
Weighted Equipment Continuous Perceived Noise Level
191
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AAAS
AAIN
AAOM
AAOO
ACGIH
AES
AES
AGMA
AHAM
AIAA
AICB
A I HA
AIMS
AI MA
AIP
AIPE
AMA
AMCA
ANSI
ARI
ASA
ASACOS
ASEE
ASHA
ASHRAE
AS ME
ACRONYMS
American Association for the Advancement of Science
American Association of Industrial Nurses
American Academy of Occupational Medicine
American Academy of Ophthamology and OtoIaryngoIogy
American Conference of Governmental Industrial Hygienists
American Engineers Society
Audio-Engineering Society
American Gear Manufacturers Association
Association of Home Appliance Manufacturers
American Institute of Aeronautics and Austronautics
International Association Against Noise (Association
Internationale Centre le Bruit)
American Industrial Hygiene Association
American Industrial Hearing Services
Acoustical and Insulating Materials Association
American Institute of Planners
American Institute of Plant Engineering
Automobile Manufacturers Association
Air Moving and Conditioning Association
American National Standards Institute
Air-Conditioning and Refrigeration Institute
Acoustical Society of America
Acoustical Society of America Committee on Standards
American Society for Engineering Education
American Speech and Hearing Association
American Society of Heating, Refrigerating and Air-
Conditioning Engineers
American Society of Mechanical Engineers
192
-------
ASQC
ASTM
ATA
BBN
B & K
BOCA
BRS
BSI
GAG I
CCH
CEI
CERN
CHABA
C I MA
CLASS
CONGAWE
CSTB
CTA
DAL
DOT
ECAC
ECE
ECE
EEC
Ef'A
ERIC
American Society for Quality Control
American Society for Testing Material
American Trucking Association
Bolt, Beranek, and Newman
Bruel & Kjaer
Builders Official Conference of America
Building Research Station
British Standards Institution
Compressed Air and Gas Institute
Committee on Conservation of Hearing
International ElectrotechnicaI Commission
European Organization for Nuclear Research
Committee on Hearing, Bioacoustic and Biomechanics
Construction Industry Manufacturers' Association
Citizen's League Against the Sonic Boom
International Study Group for Conservation of Clean Air
and Water/Western Europe/
Scientific and Technical Center for Building Construction
(Centre Scientifique et Technique du Batiment-Paris)
Chicago Transit Authority
German Noise Abatement Society (Deutscher Arbeitsring fuer
Laermbekaernpf ung)
Department of Transportation
European Civil Air Conference
Counci I of Europe
Economic Commission for Europe
European Economic Community
Engine Manufacturers' Association
Educational Resources Information Center
193
-------
ERIC/CEF
FAA
FA I
FHA
HUD
HVI
I AC
I ATA
ICAO
ICBO
I EC
IEEE
IES
IFHP
I IHT
I ITR
ILO
IMA
INCE
I RAD
ISA
ISO
JAMA
IBS
LEAA
LIA
Educational Resources Information Center/Clearinghouse
on Educational Facilities
Federal Aviation Administration
International Aeronautical Federation (Federation
Aeronautique Internationale)
Federal Housing Administration
Housing and Urban Development (Dept. of)
Home Ventilating Institute
Industrial Acoustics Company
International Air Transport Association
International Civil Aviation Organization
International Conference of Building Officials
International ElectrotechnicaI Commission
Institute of Electrical and Electronics Engineers
Institute of Environmental Sciences
International Federation for Housing and Planning
Institute in Industrial Hearing Testing
Illinois Institute of Technology Research
International Labor Office
Industrial Medical Association
Institute of Noise Control Engineering
Independent Research and Development Program
Instrument Society of America
International Standards Organization
Journal of American Medical Association
Noise Abatement Office/Zurich, Switzerland/
(Laermbekaempfungsstelle)
Law Enforcement Assistance Administration
Lead Industries Association
194
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MAC
MASAC
NAG
NAHB
NAS/NAE
NASA
NBS
NCTCOG
NEMA
NIOSH
NIPCC
NMBTA
NSBE
NSC
OAL
OCMA
OECD
OSHA
OST
PAN
PHS
PNEUROP
RMA
SAE
SESA
SIA
Metropolitan Airports Commission
Metropolitan Airports Sound Abatement Council
Noise Abatement Committee
National Association of Home Builders
National Academy of Sciences/National Academy of
Engineer!ng
National Aeronautics and Space Administration
National Bureau of Standards
North Central Texas Council of Governments
National Electrical Manufacturers Association
National Institute for Occupational Safety and Health
National Industrial Pollution Control Committee
National Machine Tool Builders Association
Northwestern Students for a Better Environment
National Safety Council
Austrian Noise Abatement Society (Oesterreicnischer
Arbeitsring fuer Laermbekaempfung)
Oil Companies Materials Association
Organization for Economic Cooperation and Development
Occupational Safety Health Administration
Office of Science and Technology
Polish Academy of Sciences (Polska Akademia Nauk)
Public Health Service
European Committee of Manufacturers of Compressed Air
Equi pment
Radio Manufacturers Association
Society of Automative Engineers
Society for Experimental Stress Analysis
Swiss Association of Engineers and Architects
(Schwe i zeri scher I ngen ieur-und "rc'~. i teKter-Vere i n)
195
-------
Sound and Vibration Institute
World Health Organization
Association of German Engineers (Verein Deutscher
Ingen ieure)
196
-------
LIST OF SOURCES
Aerospace Medicine 03-022
Air Force Systems Command,
Wright-Patterson AFB, OH 03-010
Airport Services Management 07-008
07-015
American Industrial Hygiene
Association Journal 08-001
American Journal of Public
Health and the Nation's Health 02-007
Anderson & Angevine, Inc.
E. Aurora, NY 03-017
Annals of Occupational Hygiene 01-020
07-009
08-009
AppI led Acoustics 04-004
Archives of Environmental Health 02-006
03-004
Atlanta, Public Hearings on Noise
Abatement and Control 00-001
00-002
00-003
00-004
Automotive Engineering 01-001
10-004
Bethlehem Steel Co., PA 06-003
Bolt, Beranek & Newman, Inc. 01-005
01-019
Boston, Public Hearings on Noise
Abatement and Control 00-026
00-027
Build International 06-013
Building Research Station Digest 07-003
Business Week 12-003
California Univ., L.A. 07-005
07-013
11-011
Chalmers Univ. of Technology
Goteburg, Sweden 05-005
197
-------
Chicago, Public Hearings on Noise
Abatement and Control 00-005
00-006
00-007
00-008
00-009
00-010
Chicago Dept. of Environmental
Control, IL 08-012
Chrysler Corp., Highland Pk., IL 03-012
Columbia Univ., NY 03-015
Compressed Air Magazine 01-009
06-008
06-009
Crocker, M., Proceedings of the
Purdue Noise Control Conference,
JUL 14-16, 1971 06-002
08-011
07-014
Dallas, Public Hearings on Noise
Abatement and Control 00-011
00-012
00-013
00-014
00-015
Denver, Public Hearings on Noise
Abatement and Control 00-017
00-018
00-019
00-020
00-021
00-022
Deutscher Arbeitsring Fuer
Laermbekaempfung, Wiesbaden, Germany 07-002
07-004
Ergonomics 03-021
Feingeraetetechnik 11-008
Ford Motor Co., Dearborn, Ml 11-009
Gigiyena i Sanitariya 02-003
02-012
03-014
03-023
11-003
198
-------
Gigiyena Truda i ProfessionaInye
Zabolevaniya 01-010
02-005
08-004
Hearing & Speech News 02-008
IBM Acoustics Lab., Poughkeepsie, NY 04-001
07-010
12-002
Indian Journal of Medical Research 02-002
Inglewood Dept. of Environmental
Standards; CA 04-005
06-007
08-007
Jansson, P. G., Conferences in
Connection with the International
Air Pollution Control and Noise
Abatement Exhibition, SEPT 1-6, 1971 01-006
02-001
Journal of the Acoustical Society
of America 03-002
06-006
06-011
06-012
Journal of Sound and Vibration 01-007
01-012
01-017
02-011
02-016
03-003
03-006
03-007
03-009
03-011
03-018
07-007
12-001
Kampf Dem Laerm 01-004
08-002
10-007
10-010
Koogai: Yosoku toTaisaku 03-005
03-016
Laermbekaempfung 01-002
07-017
07-018
09-001
10-006
199
-------
Machine Design 12-005
Malecki, J., Bardadin, T.,
Pamietni k XXVI I Ziazdu
Otolaryngologow Polskich w
Katowicach 1968 r. 02-013
02-014
03-020
Marinov, U., The Environment in
Israel, Israel National Committee on
Biosphere & Environment, Jerusalem,
1971 (60p.) 10-003
Meditsina 11-002
Mitre Corp., McClean, VA 08-003
Monatschrift fuer OhrenheiIkunde
und Laryngo-Rhinologie 03-001
Munich, Arbeitsbericht zur
Fortschreibung des StadtentwicklungspIanes
Nr. 3 10-005
10-008
The municipal Attorney 08-005
08-006
Municipal Review 10-009
Myles, D., An Acoustical Study of
Machinery on Logging Operations in
Eastern Canada 01-014
01-015
NAFTA 02-010
National Research Council of
Canada, Ottawa, ONT 12-004
New York, Public Hearings on Noise
Abatement and Control 00-023
00-024
00-025
Nippon Kooshu Eisei Zasshi 02-015
03-008
Noise Assessment Guidelines 07-012
Noise/News 12-007
OECD 06-010
Orvostudomany 11-001
200
-------
Oesterreichischer Arbeitsring fuer
Laermbekaempfung, Vienna, Austria 06-001
11-005
Ostergarrd Asso., West CaIdweI I, NJ 04-002
Popular Government 09-003
Die Presse 12-008
Przeglad Lekarski 11-010
Problemy Rozwoju Budownictwa 12-006
Saab-Scania/Sweden 05-004
San Francisco, Public Hearings on
Noise Abatement and Control 00-016
Sangyoo Koogai 07-011
Science and Engineering Newsletter
of Novosh Press Agency 10-001
Seewirtschaft 02-004
Sound and Vibration 01-016
02-009
05-001
05-002
05-003
06-005
08-008
11-004
Stanford Research Inst., Menlo
Pk., CA 03-013
11-006
Univ. of So. Florida, Tampa 09-002
Urban Design Bulletin 11-007
Urban Transportation Center,
Wash., DC 04-003
Vooosnabzheniye i Sanitarnaya
Tekhnika 03-019
Washington, Public Hearings on
Noise Abatement and Control 00-028
00-029
00-030
00-031
00-032
00-033
00-034
201
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Washing-ton, (Continued) 00-035
00-036
00-037
00-038
Zagadnienia Akustyczne w Zakladach
Przemyslowych 06-004
Zurich City Police 09-004
202
*U.S GOVERNMENT PRINTING OFFICE:i972 484-487/3561-3
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