NTID 73.4
IMPACT CHARACTERIZATION OF NOISE
INCLUDING IMPLICATIONS OF
IDENTIFYING AND ACHIEVING LEVELS
OF CUMULATIVE NOISE EXPOSURE
ENVIRONMENTAL PROTECTION AGENCY
AIRCRAFT/AIRPORT NOISE STUDY REPORT
27 JULY 1973
-------
IMPACT CHARACTERIZATION OF NOISE
INCLUDING IMPLICATIONS OF IDENTIFYING AND
ACHIEVING LEVELS OF CUMULATIVE NOISE EXPOSURE
ENVIRONMENTAL PROTECTION AGENCY
AIRCRAFT/AIRPORT NOISE STUDY REPORT
27 JULY 1973
HENNING VON GIERKE, TASK GROUP CHAIRMAN
This document is the result of an extensive task force effort to gather all
available data pertinent to the subject discussed herein. It represents the
interpretation of such data by the task group chairman responsible for
this specific report. It does not necessarily reflect the official views of EPA
and does not constitute a standard, specification, or regulation.
-------
PREFACE
The Noise Control Act of 1972 (Public Law 92-574) directs the Environmental
Protection Agency (EPA) to study the adequacy of current and planned regulatory action
taken by the Federal Aviation Administration (FAA) in the exercise of FAA authority to
abate and control aircraft/airport noise. The study is to be conducted in consultation
with appropriate Federal, state and local agencies and interested persons. Further,
this study is to include consideration of additional Federal and state authorities and
measures available to airports and local governments in controlling aircraft noise. The
resulting report is to be submitted to Congress on or before July 27, 1973.
The governing provision of the 1972 Act states:
"Sec. 7(a). The Administrator, after consultation with appropriate Federal, state,
and local agencies and interested persons, shall conduct a study of the (1) adequacy
of Federal Aviation Administration flight and operational noise controls; (2) adequacy
of noise emission standards on new and existing aircraft, together with recommenda-
tions on the retrofitting and phaseout of existing aircraft; (3) implications of identi-
fying and achieving levels of cumulative noise exposure around airports; and (4)
additional measures available to airport operators and local governments to control
aircraft noise. He shall report on such study to the Committee on Interstate and
Foreign Commerce of the House of Representatives and the Committees on Commerce
and Public Works of the Senate within nine months after the date of the enactment of
this act."
Under Section 7(b) of the Act, not earlier than the date of submission of the report to
Congress, the Environmental Protection Agency is to:
"Submit to the Federal Aviation Administration proposed regulations to provide such
control and abatement of aircraft noise and sonic boom (including control and abate-
ment through the exercise of any of the FAA's regulatory authority over air commerce
or transportation or over aircraft or airport operations) as EPA determines is
necessary to protect the public health and welfare. "
The study to develop the Section 7(a) report was carried out through a participatory
and consultive process involving a task force. That task force was made up of six task
groups. The functions of these six task groups were to:
111
-------
1. Consider legal and institutional aspects of aircraft and airport noise and the
apportionment of authority between Federal, state, and local governments.
2. Consider aircraft and airport operations including monitoring, enforcement,
safety, and costs.
3. Consider the characterization of the impact of airport community noise and to
develop a cumulative noise exposure measure.
4. Identify noise source abatement technology, including retrofit, and to conduct
cost analyses.
5. Review and analyze present and planned FAA noise regulatory actions and their
consequences regarding aircraft and airport operations.
6. Consider military aircraft and airport noise and opportunities for reduction of
such noise without inhibition of military missions.
The membership of the task force was enlisted by sending letters of invitation to a
sampling of organizations intended to constitute a representation of the various sectors
of interest. These organizations included other Federal agencies; organizations repre-
senting state and local governments, environmental and consumer action groups,
professional societies, pilots, air traffic controllers, airport proprietors, airlines,
users of general aviation aircraft, and aircraft manufacturers. In addition to the invita-
tion letters, a press release was distributed concerning the study, and additional persons
or organizations expressing interest were included into the task force. Written inputs
from others, including all citizen noise complaint letters received over the period of the
study, were called to the attention of appropriate task group leaders and placed in the
public master file for reference.
OBJECTIVE
As part of the aircraft/airport noise study required by Section 7 of the Noise
Control Act of 1972, the Environmental Protection Agency must study the "implica-
tions of identifying and achieving levels of cumulative noise exposure around airports. "
In support of this requirement, TaskGroup 3 was asked to:
1. Determine the merits and shortcomings of methods to characterize the
impact of noise of present or proposed airport/aircraft operations on the
public health and welfare.
2. Determine which of such methods is most suitable for adoption by the Fed-
eral Government, keeping in mind (1) the role of airport operators and
IV
-------
owners and the rights of the public; (2) the costs of noise monitoring, (3)
the implications for enforcement of regulations; and (4) the relationships
to other measures for environmental source description and control.
3. Determine the implications of issuing Federal regulations establishing a
standard method for characterizing the noise from air craft/airport oper-
ations and of specifying maximum permissible levels for the protection of
the public health and welfare.
APPROACH
The Task Group met five times at intervals of two or three weeks (see Appendix
F for minutes of meetings and list of organizations and individuals participating)
to collect the necessary background information (see Appendix G) and to arrive at
the conclusions and recommendations presented in this report. The difficult and
controversial subjects of the Task Group assignment made a complete agreement and
a consensus of all members on all subjects impossible. Exceptions and objections to
the report by individual members or organizations are listed in Appendix H. In
spite of these it is hoped that the report contains the reasonable and balanced majority
view as integrated by the chairman.
The fundamental bases for the Task Group's approach were:
1. A scientifically, economically, and socially sound and defensible noise
control program requires that any measure or method used to characterize
the impact of aircraft/airport operations noise on the public health and
welfare must in principle also be able to characterize the impact of all
other types of noise regardless of their origin. Aircraft noise exposure mus
be measured by the same yardstick as other noises. Neglect of this require-
ment is to a large extent responsible for some of the controversies in this
area and the absence of clearly identified national noise goals.
2. Only if this first condition is fulfilled can aircraft noise exposure be added
to other noise exposures to which people are subjected, so that the total
noise exposure of individuals or the public can be measured or calculated.
Discussion of noise effects with respect to health and welfare make sense
only in terms of total noise exposure. Permissible or maximum desirable
levels of noise for each source, and the duration of people's exposure to
these levels must therefore be derived from the permissible or maximum
desirable noise from any source to which the public may be exposed without
-------
an undue effect on health or welfare. (Choosing the same measure for
people's exposure to aircraft noise as is used to measure noise exposure
from other sources does not necessarily imply that the same criteria of
acceptability must be chosen for all sources.)
3. If permissible noise levels are determined on the basis of the total noise
exposure of individual people, any system used to characterize noise impact
with respect tc public health and welfare must be able to measure and/or
calculate the noise exposure of individuals moving through different noise
environments during their daily living routine. For example, occupational
noise exposure during working hours, traffic noise during transportation to
and from work, and the noise of the environment at home during evening and
night all must be added to give the average noise level to which an individual
is exposed during a day. All regulations and standards with respect both to
environmental noise levels and to individual source emissions must ultimately
be based on and justified by desirable or permissible values for total individual
noise exposures, even though such regulations may be stated in terms of the
average daily exposure level, at a specified location, due to an individual
source (such as aircraft), or in terms of exposure of individuals to this source
only.
4. The requirement to agree on such a universal measure to characterize cumu-
lative human noise exposure is very urgent. Without such a measure no
long-term, meaningful goals and standards can be set. This urgency clearly
justifies selection of the best characterization method presently available
without waiting for further research data and refinements. The urgency to
develop a common measure for all types of noise exposure justifies whatever
simplifications are required now to make it a practical tool for environmental
noise control requirements and standards.
5. A practical simple measure of environmental noise cannot and need not take
into account secondary effects. Neglecting secondary details in the measure-
ment and control of environmental noise does not mean that these details are
not important or that attention should not be paid to them through other con-
trol measures. For example, one-time noise events, high instantaneous
peak values or objectionable discrete tones of individual sources must be
separately controlled by emission noise standards. Standards for cumulative
VI
-------
environmental noise exposure and emission/certifications standards must
complement each other. The emission or source standard can consider the
details of the source characteristics and can employ methods of measure-
ment, data analysis and interpretation appropriate for the characteristics of
the particular noise or for effective noise control engineering on this noise
source. However, it is mandatory that all detailed source standards can be
translatable into one common noise measure. Exposures to all kinds of
noise can then be added in this common measure of exposure to give a
measure of total accumulated noise exposure.
Section 1 of this report gives the selected common measure of average
noise level recommended by the Task Group for general use by the Federal
Government for characterizing all types of environmental noise exposures.
Appendix A gives the justification for the recommended procedure and its relation
to other existing methods.
Section 2 gives details about the application of the noise exposure measure
to the aircraft/airport noise situation, and about predicting, measuring and
monitoring environmental noise. Most task group members agreed with the
approach of Sections 1 and 2.
Section 3 discussesr the basis for selecting maximum permissible noise exposure
with respect to public health and welfare and recommends specific maximum cumulative
exposure for the average person, to be adopted by the Federal Government.
Detailed justification for the health and welfare criteria selected, and for the
maximum permissible noise exposures recommended is presented in Appendix B
(with respect to hearing loss), Appendix C (with respect to interference with speech
communication) and Appendix D (with respect to annoyance).
The economic impact of these recommendations is discussed semi-quantatively
in Section 3 and in more detail in the reports of task groups 1, 2, 4 and 5. An
analysis of the overall economic impact of achieving these permissible levels, and an
analysis of a recommended time schedule was beyond the task group's scope. These
recommendations should, therefore, be considered by the Administrator in the overall
context of the requirements of the Noise Control Act. The agreement among members
of the task group with respect to the maximum permissible noise exposure was not as
Vll
-------
good as for Sections 1 and 2. However, it was felt by the majority of the task group
that the adoption of a goal for maximum permissible exposure in clearly
defined and measurable units would be an important and significant step forward.
Progress on specific tasks, such as the aircraft/airport study directed by the
Noise Control Act of 1972, can then be evaluated in terms of progress toward this
goal.
Section 4 presents the conclusions and recommendations of the task group.
viu
-------
CONTENTS
Section Page
1 THE MEASURE OF ENVIRONMENTAL NOISE EXPOSURE 1
Physical Attributes of Sound Affecting Human Response 2
Magnitude 2
Frequency Distribution 2
Time Distribution 4
Development of the Measure of Community Noise 5
Frequency Weighting 5
Average Sound Level 6
Daytime/Nighttime Average Sound Level 6
Seasonal Factors 8
Indoor-Outdoor Factors 8
Psychological/Sociological Factors 10
Definition of Day-Night Average Sound Level as the
Measure for Community Cumulative Noise Exposure 10
Sound Exposure Level - A Measure of Noise from
One Event 11
2 APPLICATION OF DAY-NIGHT SOUND LEVEL TO AIRPORT
NOISE 13
Measurement of Day-Night Average Sound Level 13
Prediction of Day-Night Level for Airport Noise 14
Comparison of Day-Night Average Sound Level with
Other Airport Noise Descriptors 16
The Effects of Other Noise Sources on Day-Night Average
Level from Airport Operations I7
3 BASIS FOR SELECTING MAXIMUM PERMISSIBLE AVERAGE
NOISE LEVELS 19
Hearing Loss 21
Direct Effect 21
Indirect Effects 22
Day-Night Average Noise Levels to Prevent Hearing
Loss 24
Speech Communication 26
Annoyance 28
General Health Effects of Noise 33
Natural Indoor Noise "Floor" 35
Number of People Impacted Versus Various Goals for
the Day-Night Average Sound Level 36
Summary of Effects of Noise on People at Various Values
of Day-Night Average Sound Level 39
ix
-------
CONTENTS (Continued)
Section Page
4 CONCLUSIONS AND RECOMMENDATIONS 41
Conclusions 41
Recommendations 45
R REFERENCES R-l
APPENDICES
A JUSTIFICATION OF THE USE OF THE AVERAGE SOUND
LEVEL AS A MEASURE OF COMMUNITY NOISE A-l
B HEARING LOSS EXPECTED FOR VARIOUS L^ VALUES B-l
C SPEECH COMMUNICATIONS C-I
Speech Interference Due to Noise C-l
Indoor Speech Communications C-5
D RELATIONSHIPS BETWEEN ANNOYANCE AND AVERAGE
NOISE LEVEL D-l
First London-Heathrow Survey D-l
Combined Results of Second London Survey and
Tracer Surveys D-2
Judgment of Noisiness at Urban Residential Sites D-2
Community Reaction D-3
E SPECIFIC RECOMMENDATIONS FOR PREDICTING L,
FOR AIRCRAFT/AIRPORT OPERATIONS E-l
F MINUTES OF TASK GROUP 3 MEETINGS AND LIST OF
ORGANIZATIONS AND INDIVIDUALS PARTICIPATING IN
TASK GROUP 3 ACTIVITIES F-l
G POSITION PAPERS AND MATERIAL SUBMITTED BY TASK
GROUP 3 MEMBERS OR OUTSIDE ORGANIZATIONS G-l
H POSITION PAPERS SUBMITTED BY TASK GROUP 3
MEMBERS WITH RESPECT TO REPORT OF TASK
GROUP 3 H-l
I LIST OF REFERENCES AND MATERIAL NOT PROVIDED
IN THIS DOCUMENT 1-1
GLOSSARY FOR NOISE MEASURES GLOSSARY-1
-------
LIST OF ILLUSTRATIONS
Figure Page
1 Outdoor Environmental Noise 12
2 Maximum Percentage Interference with Sentences as a Function
of the Day-Night Average Noise Level. (Percentage Interference
Equals 100 Minus Percentage Intelligibility, and L, is Based on
Ld + 3) dn 29
3 Intercomparison of Various Measures of Individual Annoyance and
Community Reaction as a Function of the Day-Night Average
Noise Level, L, in Decibels 31
A-l L for Intermittent Lmax Added to L^ A-16
A-2 L6q for a Repeated Series of n Triangular Signals Overlaid on a
Background Level L, dB (r = Duration at L - 10 dB in
Seconds) b m&X A-17
A-3 Difference Between L and L for a Normal Distribution Having
s Standard Deviation6^ °
A-18
A-4 Percentile of a Normal Distribution that is Equal to L A-19
eq
A-5 Difference Between L1rt and L for a Normal Distribution A-20
-Lu GC[
A-6 Permissible Normal Distributions of L under HUD Standards A-21
eq
A-7 Comparison of the Difference Between Day and Night Values of
the Equivalent Sound Level with the Day-Night Average Sound
Level, L, A-22
C-l Maximum Distances Over Which Conversation is Considered to
be Satisfactorily Intelligible {Sentence Intelligibility = 95%
Except as Noted) C-3
C-2 Cumulative Distribution of Typical Community Noises During
the Daytime C -9
XI
-------
LIST OF ILLUSTRATIONS (Continued)
Figure Page
C-3 Maximum Percentage Interference with Sentences as a Function
of the Day-Night Average Noise Level. (Percentage Inter-
ference Equals 100 Minus Percentage Intelligibility, and L,
is Based on Lrf + 3) n C-12
D-l Average Degree of Annoyance as a Function of the Approximate
Day-Night Average Noise Level - Results of First London
Heathrow Survey D-5
D-2 Percentage Highly Annoyed as Function of Approximate Day-
Night Average Noise Level - Results of First London Heathrow
Survey D-G
D-3 Combined Results - British and U. S. Surveys (After Borsky,
Ref. 18) D-7
D-4 Judged Noisiness at Automobile Manufacturers Association
Survey Sites D-8
XII
-------
LIST OF TABLES
Table Page
1 Maximum noise induced permanent threshold shift in decibels,
at various audiometric frequencies, for the most sensitive
10 percent of the population, assuming a 40-year exposure
for 8 hours per day, as a function of the A-weighted average
sound level of broad-band noise 23
2 Summary of permissible values of the outdoor day-night average
sound level in decibels for intermittent aircraft noise, under
two alternative constraints and for three values of the difference
between day and night values of the average sound level 25
3 Steady A-weighted noise levels that allow communication with
95% sentence intelligibility over various distances outdoors
for different voice levels 27
4 Percentages of the population near airports who are highly
annoyed and who lodge complaints about noise, for various
values of the day-night average sound level of aircraft noise 33
5 Measured values representative of indoor average sound levels
where external noise intrusion is not significant 35
6 Estimated number of people exposed to noise from aircraft
operations, freeway traffic and urban road and street traffic
at various values of outdoor day-night average sound level 37
7 Health effects of noise at different values of outdoor day-night
average sound level, L , in decibels 40
B-l Summary of the permanent hearing damage effects expected for
continuous noise exposure at various values of the A-weighted
average sound level B-2
B-2 Expected hearing changes for various A-weighted average sound
levels in dB B-6
C-l Steady A-weighted noise levels that allow communication with 95
percent sentence intelligibility over various distances outdoors
for different voice levels C-4
C-2 Evaluation of indoor speech communications C-6
C-3 Maximum permissible average sound levels that permit 95 percent
sentence intelligibility at a distance of 2 meters, using normal
voice effort C-8
Xlll
-------
LIST OF TABLES (Continued)
Table Page
C-4 Percent interference with sentence intelligibility in the presence
of a steady intruding noise cycled on and off periodically in such
a way as to maintain constant average sound level, as a function
of the maximum noise level and duration C-ll
xiv
-------
SECTION 1
THE MEASURE OF ENVIRONMENTAL NOISE EXPOSURE
Section 7 of the Noise Control Act of 1972 directs the Environmental Protection
Agency to study the "implications of identifying and achieving levels of cumulative
noise exposure around airports. " A primary consideration in this study is the
specification of a measure for the noise produced at different locations in communi-
ties near an airport. A suitable choice for the measure should include the effects
of average noise level and of exposure time.
A physical measure of cumulative noise exposure applicable to evaluation of
airport noise should be based on consideration of the following requirements:
1. The measure should correlate well with the human responses regarding
hearing loss, sleep and speech interference, and annoyance
due to noise exposure.
2. The measure should be capable of assessing the accumulated effect of all
noises during a long time.
3. The measure should be simple enough that it can be obtained by direct
measurement without extensive instrumentation or elaborate analysis
equipment.
4. The required measurement equipment, with standardized characteristics,
should be commercially available.
5. The measure for airport noise should be closely related to measures
currently used for noise from other sources.
6. The single measure of noise at a given location should be predictable,
within an acceptable tolerance, from knowledge of the physical events
producing the noise.
-------
The remainder of this section discusses how these requirements were considered
in the selection of the measure to be used for evaluating environmental noise around
an airport.
PHYSICAL ATTRIBUTES OF SOUND AFFECTING HUMAN RESPONSE
The accumulated evidence of research on human response to sound indicates
clearly that the magnitude of sound as a function of frequency and time are basic indi-
cators of human response to sound. These facts are reviewed here.
MAGNITUDE
Sound is a. pressure fluctuation in the air; the magnitude of the sound describes the
physical sound, in the air; (loudness on the other hand, refers to how people judge the
sound when they hear it). Magnitude is stated in terms of the amplitude of the pressure
fluctuation. The range of magnitude between the faintest audible sound and the loudest
sound the ear can withstand is so enormous (a ratio of about 1,000,000,000,000 to 1)
that it would be very awkward to express sound pressure fluctuations directly in
pressure units. Instead, this range is "compressed" by expressing the sound pressure
on a logarithmic scale. Thus sound is described in terms of the sound pressure level
(SPL), which is ten times the common logarithm of the ratio of the sound pressure in
question to a (stated or understood) reference sound pressure, usually 20 micro-newtons
per square meter.
FREQUENCY DISTRIBUTION
The response of human beings to sound depends strongly on the frequency of the
sound. In general, people are less sensitive to sounds of low frequency, such as 100
hertz (Hz),* than to sounds at 1000 Hz; also at high frequency, such as 8000 Hz, sen-
sitivity decreases. Two basic approaches to account for this difference in response
to different frequencies are (1) to segment the sound pressure spectrum into a series
of contiguous frequency bands by electrical filters, so as to display the distribution
of sound energy over the frequency range or (2) to apply a weighting to the overall
Hertz is the international standard unit of frequency, until recently called "cycles per
second"; it refers to the number of pressure fluctuations per second in the sound wave.
-------
spectrum in such a way that the sounds at various frequencies are weighted in much
the same way as the human ear hears them.
In the first approach a sound is segmented into sound pressure levels in 24 differ-
ent frequency bands, which may be used to calculate an estimate of the "loudness" or
"noisiness" sensation which the sound may be expected to cause. This form of analy-
sis into bands is usually employed when detailed engineering studies of noise sources
are required. It is much too complicated (i.e. , expensive) for monitoring noise
exposure.
To perform such analysis, especially for time varying sounds, requires a very
complex set of equipment. A frequency-weighted sound pressure level, on the other
hand, is a one-number measure of noise that can be obtained with simple equipment.
Such a sound level with a designated frequency weighting is called simply sound level.
Although this approach is not satisfactory for detailed analysis for engineering noise
control, it provides a satisfactory description of noise from a response viewpoint,
within the accuracy reasonable for community noise-evaluations.
With respect to both simplicity and adequacy for characterizing human response,
a frequency-weighted sound level should be used by the Environmental Protection
Agency for the evaluation of community noise. Several frequency weightings have been
proposed for general use in the assessment of response to noise, differing primarily
in the way sounds at frequencies between 1000 and 4000 Hz are evaluated.
The A-weighting, standardized in current sound level meter specifications, has
been widely used for transportation and community noise description (Ref. 1). For
many noises the A-weighted sound level has been found to correlate as well with
human response as more complex measures, such as the calculated perceived noise
level or the loudness level derived from spectral analysis (Ref. 2). However, psycho-
acoustic research indicates that, at least for some noise signals, a different frequency
weighting which increases the sensitivity to the 1000-4000 Hz region is more reliable
(Ref. 3). Various forms of this alternative weighting function have been proposed;
they will be referred to here as "D-weighting. " None of these alternative weightings
-------
has progressed in acceptance to the point where a standard has been approved for
commercially available instrumentation.
One difficulty in the use of the A- or D-weighted sound level is that psychoacoustic
judgment data indicate that effects of tonal components are sometimes not adequately
accounted for by a simple sound level.
Some current ratings attempt to correct for tonal components. For example,
in the present aircraft noise certification procedures, "Noise Standards: Aircraft
Type Certification," FAR Part 36, the presence of tones is identified by a complex
frequency analysis procedure. If the tones protrude above the adjacent random noise
spectrum, a penalty is applied beyond the direct calculation of perceived noise level
alone.
After consideration of this problem, the Task Group concluded that the presence
of a tone penalty in certification procedures effectively encourages a manufacturer to
minimize tones in the sound of aircraft. Thus, certification requirements will mini-
mize the need to consider tones in an environmental noise measure, so long as tonal
effects are properly considered under source certification.
TIME DISTRIBUTION
Most noise sources generate sound levels with recognizable temporal patterns.
The level may be constant, as for a steady source, or it may vary with time, as with
the noise produced at a given point on the ground during the passage of an aircraft
in flight. Since response to noise is a function of the duration of the noise, it is
necessary to have some description of its time pattern.
The most basic description of the time-varying nature of a noise signal observed
at any point is a record of sound level as a function of time. The symbolic expression
for a time varying sound level is L . Such a function might describe the pressure
history at a fixed location for any one of a number of similar noise events. Alter-
nately, L might describe the fluctuating sound pressure level encountered by a
-------
single observer moving through various noise environments. Where a number of
successive or overlapping noisy events occur, it is useful to have a continuous
record of sound level as a function of time. From such a record, a statistical distri-
bution of sound level versus percent of the total observation period can be
derived. When such a distribution is obtained, it is common practice to identify by
subscripts the respective sound levels exceeded during specified percentages of the
observation time. Thus L is the sound level exceeded 90 percent of the time; L
yo 50
is the median value; L is the sound level exceeded 10 percent of the time.
DEVELOPMENT OF THE MEASURE OF COMMUNITY NOISE
The first step toward specifying a measure for cumulative exposure to environ-
mental/community noise is to choose a measure that accounts for the varying sensi-
tivity of the ear with frequency. Other factors that affect human response must be
examined also. The factors considered most relevant to the selection of a suitable
noise measure are discussed in this section.
FREQUENCY WEIGHTING
A conclusion of the previous section is that a frequency weighted sound pressure
level is the most reasonable choice for describing the magnitude of environmental
noise. In order to use available instrumentation for direct measurement, the A fre-
quency weighting is the only suitable choice. *
The indications that a "D-weighting" might ultimately be more suitable for evalu-
ating the integrated effects of noise on man, than the A-weighting, however, suggests
that at such time as a "D-weighting" becomes standardized and available in commer-
cial instrumentation, its value as the weighting for environmental noise should be
considered, to determine if a change from the A-weighting is warranted.
*A11 sound levels in this report are A-weighted sound pressure levels in decibels with
reference to 20 micro-newtons per square meter.
-------
AVERAGE SOUND LEVEL
As noted above, the measure of magnitude of noise in the community, at a given
instant and place, is the fluctuating A-weighted sound level, often called simply sound
level or noise level. The durations of the various sounds must be taken into account
in an appraisal of "levels of cumulative noise exposure around airports." This is done
by giving the average sound level during a stated time period. (Justification for the
use of the average sound level is given in Appendix A).
This average sound level is sometimes called equivalent sound level. The symbol
for both of them is L . The average (equivalent) sound level is the constant sound
level which, in a given situation and time period, would convey the same sound energy
as does an actual time-varying sound. Two sounds, one of which contains twice as
much energy but lasts only half as long as the other, would be characterized by the
same average sound level; so would a sound with four times the energy lasting 1/4 as
long, etc. This relation is often called the equal-energy rule. The average (equiva-
lent) level for a number of events is somewhat greater than the sum of the sound
levels for the various events divided by the number of them, by an amount that depends
upon the range of variation of the sound level.
Some specifically named average sound levels are:
1. Hourly (average) sound level, L, ,
2. Daytime (average) sound level, L ,,
3. Nighttime (average) sound level, L .
For the present purpose, day extends from 7 a.m. up to 10 p.m. (0700-2200); night
from 10 p.m. up to 7 a.m. (2200-0700) the next day.
DAYTIME/NIGHTTIME AVERAGE SOUND LEVEL
The repetitive cycle of events in most environments leads to the natural choice
of a 24-hour day as the base period for evaluation of environmental noise. Most
-------
airport operations are quite stable in their day-to-day schedules. However, at many
airports seasonal variations in schedules will change the frequency of aircraft opera-
tions during various months over the year. Thus, in assessing the environmental
effect of an airport, the daily average noise level, averaged over an annual period,
should be considered. This would be expressed as a yearly average of daytime/night-
time average sound level.
It is important to account for the difference in response of people in residential
areas to noises that occur during sleeping hours as compared to waking hours. During
nighttime, exterior background noises generally drop in level from their daytime
values (see Appendix A). Further, the activity of most households decreases at
night, lowering the internally generated noise levels. Thus, intrusive noise events
often become more noticeable at night, since the increase in noise level of the event
over background noise is greater than for daytime conditions.
Methods for accounting for these daytime/nighttime conditions have been devel-
oped in a number of different noise assessment methods employed around the world
(Ref. 6). In general, the method used is to apply a penalty to noise events occurring
during nighttime hours, that is, to treat night-time noises as though they were several
decibels noisier than they actually are. Two approaches to identifying time periods
have been employed: one divides the 24-hour day into two periods, the waking and
sleeping hours, while the other divides the 24-hours into three periodsday, evening
and night.
The penalties applied to the non-daytime periods differ slightly among the differ-
ent countries (Ref. 4), but most of them penalize night activities by (nominally) 10 dB;
the evening penalty, if used, is (nominally) 5 dB.
An examination of the numerical effects of using two periods versus three periods
per day shows that for any reasonable distribution of aircraft flight operations, the
two-period day and the three-period day are essentially identical (e.g. that is, the
24-hour equivalent sound levels are equal within a few tenths of a decibel. See
Appendix A). It is recommended that the simpler two-period day be used.
-------
Next we must select the actual times defining the day and night period. A sug-
gestion that this choice be made optional within certain limits was considered but
rejected, since a fixed schedule across the country was strongly preferred.
It was further considered whether the sudden imposition of a penalty at a specific
time is reasonable, e.g., no penalty before a specific clock time, then imposition of
the penalty a minute later. However, we concluded that the complexity of a variable
time transition outweighed the possible benefits of its effect on final numerical values
of average sound level and was not considered further.
These considerations lead to the recommendations of an average sound level during
a 24-hour day, with a 10 dB penalty for the nighttime period from 2200 to 0700.
SEASONAL FACTORS
Consideration was given to the effects of seasonal variation of temperature on
annoyance. Most studies indicate that, at least in colder climates, more complaints
about noise occur during the summer months; presumably, this is because more
people have windows open, and thus less noise reduction is provided by residential
structures than in winter when windows are closed. On the other hand, home air-
conditioning tends to keep windows closed during summer, and this factor may tend
to equalize the winter and summer month complaints.
It was concluded that it is not reasonable to try to generalize any corrections for
seasonal effects. Any such considerations should be applied on a local basis through
planning ordinances or building code specifications where the local authorities have
jurisdiction.
INDOOR-OUTDOOR FACTORS
The eventual purpose for establishing environmental noise level measures is to
relate noise exposure to human response. Therefore, the noise levels to which
people are actually exposed is of primary interest. While it may be more expedient
-------
to measure or predict outdoor noise levels, the fact that people spend most of their
time indoors is significant. Two points then need to be considered. First, the
proportion of time different segments of the population are indoors compared to
outdoors, and second, the amount of noise reduction provided by various building
structures.
The percentages of time different people spend indoors and outdoors depends on
their age and occupation, and on geographical and climatological factors. These
considerations properly come into play in the selection of specific criterion values
for various situations, but not directly in the description of the physical noise
exposure levels.
The effective noise reduction of buildings is also situation-dependent. If one
restricts attention to residential structures, guidelines for noise reduction can be
provided so that the indoor noise level may be estimated from the outdoor noise
level from the same exterior noise source.
Data on the reduction of aircraft noise afforded by a range of residential
structures are available (Ref. 5). These data indicate that houses can be approxi-
mately categorized into "warm climate" and "cold climate" types. Further, data
are available for typical open-window and closed-window conditions. These data
indicate a wide range of noise reduction provided by buildings within a given com-
munity due to differences in the use of materials, building techniques, and individual
building plans. Nevertheless, for planning purposes, typical reduction in sound level
from outside to inside a house is as follows:
A-Weighted Sound Level Reduction Due to Houses in Warm
and Cold Climates, With Windows Open and Closed.
Warm climate
Cold
Appr
Climate
ox. national average*
Windows
Open
12 dB
17
15
Windows
Closed
24 dB
27
25
(extracted from Ref. 5)
*Valid for total window opening per room of 2 sq. ft. or less.
9
-------
PSYCHOLOGICAL/SOCIOLOGICAL FACTORS
We do not propose to include in the measure of environmental noise any "non-
acoustical" weighting functions to account for differences in people's response to noise,
such as different acceptability of different noise sources, different attitudes of differ-
ent populations toward noise, differing familiarity with the noise or socio-economic
differences, etc. Such factors were included in previous ratings, such as Composite
Noise Rating (CNR). The reason for not including these factors in the present
measure are twofold:
1. Their inclusion would make it impossible to verify predicted values with
actual measured sound levels;
2. Such factors cannot be justified if the basic purpose of the measure is not
to predict the present-day response/complaint behavior of specific com-
munities, but rather to establish average noise level goals with public health
and welfare as the criterion.
It is recommended that such factors be considered when decisions about land use
planning and maximum permissible noise exposure are being made. (See items 7
and 8 of conclusions, Section 4.)
DEFINITION OF DAY-NIGHT AVERAGE SOUND LEVEL AS THE MEASURE FOR
COMMUNITY CUMULATIVE NOISE EXPOSURE
The previous sections support a basic measure for quantifying average noise
around airports, namely the average A-weighted sound level, during a 24-hour time
period, with a 10 decibel penalty applied to nighttime sound levels. In this formu-
lation, "daytime" is the period between 0700 in the morning and 2200 (10 o'clock) at
night; "nighttime" is the period from 2200 to 0700 hours the next day. A mathemati-
cal description for this formulation is provided in Appendix A.
10
-------
The basic quantity described above is termed the "Day-Night Average Sound
Level, " or more briefly, "Day-Night Level. " The unit for this quantity is the
decibel, and the letter symbol for it is L^ . Figure 1 shows typical values of L
for various types of environment, with corresponding subjective evaluations.
SOUND EXPOSURE LEVEL - A MEASURE OF NOISE FROM ONE EVENT
It is convenient to define a measure that accounts for the total accumulation of
sound during an observation period or for a single noisy event; one such measure is
called the Sound Exposure Level. In contrast to an average sound level, sound ex-
posure level represents the summation, without averaging, of all sound energy during
an entire event or observation period. Thus, even though the noise level may fluc-
tuate up and down, the sound exposure level is always increasing. In principle, one
could measure the sound exposure level as the sum of sound energy received during
a very long period, like the lifetime of a man. Many important sounds, however,
are of significant magnitude only during a much shorter time, like a few seconds.
Hence, the sound exposure level of an aircraft flyover may practically be measured
during the 10 or 20 seconds for which the sound level is within 10 (or 20) decibels of
the maximum level.
Sound exposure level is the level of the time integral of A-weighted squared
sound pressure for a specified time interval or event, with reference to a duration
of one second, The unit of sound exposure level is the decibel, and the letter symbol
for it is L .
e
The sound exposure level in decibels will exceed the equivalent sound level during
some selected time interval by ten times the logarithm of the duration of the time
interval in seconds. For example, the equivalent level (the average sound level) for
a constant sound of 60 decibels observed for 1, 10, or 100 seconds will be 60 deci-
bels in all three cases; the sound exposure levels for the same three conditions will
be, respectively, 60, 70, and 80 decibels.
11
-------
QUALITATIVE
DESCRIPTIONS
City Noise
(Downtown Major
Metropolis)
Small Town &
Quiet Suburban
DAY-NIGHT AVERAGE
SOUND LEVEL
DECIBELS
-90-
-80-
-70-
-60-
-40-
OUTDOOR LOCATIONS
3rd Floor Apartment Next to Freeway
3/4 Mile From Touch Down At
At Major Airport
Downtown Los Angeles
With Some Construction Activity
2nd Floor Apartment in Harlem
Row Housing on Major Avenue
in Boston
Watts - 8 Miles from Touch Down
at Major Airport
Newport - 3.5 Miles from Takeoff at
Small Airport
Los Angeles Old Residential Area
Fillmore - Small Town Cul-de-Sac
San Diego Wooded Residential
Tomato Field on Farm
Figure 1. Outdoor Day-Night Average Sound Level in dB (re 20 Micronewtons/
Sq. Meter) at Various Locations
12
-------
SECTION 2
APPLICATION OF DAY-NIGHT SOUND LEVEL TO AIRPORT NOISE
Among the requirements for a suitable measure of cumulative noise exposure
around an airport are the ability to measure it with available instrumentation and the
ability to predict expected values from a knowledge of physical characteristics of the
noise sources. These matters are discussed in this section.
MEASUREMENT OF DAY-NIGHT AVERAGE SOUND LEVEL
The primary requirement in measuring average level is the ability to obtain an
"energy average" of A-weighted sound level over the separate daytime and nighttime
periods. These measurements may be performed with a variety of existing instrumen-
tation, ranging from a standard sound level meter, used in conjunction with some
sound level-history recorder such as a graphic level recorder, through meters that
provide averaged noise levels periodically on an hourly basis, up to the more
elaborate computerized monitoring systems now coming into use at some major
airports.
The least sophisticated form of instrumentation, the combination of a sound level
meter and a graphic level recorder, requires that, the graphic recording of sound
level as a function of time be segmented into the various intervals in which the sound
level lies. That is, using a series of discrete "windows, " say 1 to 5 dB in width,
the percentage of time that the sound level lies within each window is determined.
This sound level/time distribution can be determined either manually or with so-
called "statistical distribution analyzers" produced by various equipment manufac-
turers. The energy average of the sound level pattern during the observation period
can then be computed from this level distribution.
13
-------
The recently available exposure meters, or integrating sound level meters, per-
form this same function without the use of a level recorder. Most of these instru-
ments provide hourly average sound levels which may then be appropriately combined
to obtain the day-night average level, L . Several manufacturers also offer instru-
ments in such a form that the 24-hour value of L , may be obtained directly from the
an
instrument, including the provision of the nighttime weighting function.
The advantage of the above devices is their portability. They are suited to sur-
veys of relatively short duration, e.g. days to weeks. Where continuous monitoring
is desired, e. g. on an annual basis, it is more convenient to utilize a permanent
monitoring system with a number of fixed microphones, and to feed the sound signals
through telephone lines to a central recording station. A small digital computer may
be incorporated with the central system so that a variety of analyses can be made.
Such quantities as maximum sound level per event, sound exposure level, as well as
hourlv and daily average sound levels may be easily obtained from such systems.
Clearly, the choice of measurement capability depends on the time span of in-
terest, the funds available, the regulatory requirements, and other matters unique
to each situation. It should be observed, however, that the intent of day-night sound
level is to obtain a measure of the average sound level integrated over a long enough
period of time to insure that variability in measurements due to weather, operational
factors, traffic densities or seasonal effects are properly accounted for in the
measurements.
PREDICTION OF DAY-NIGHT LEVEL FOR AIRPORT NOISE
In considering environmental noise in the vicinity of airports, it is important to
be able to predict the noise environment for planning purposes. The measure chosen
to describe environmental noise should also be readily adaptable to the various pre-
dictive methodologies that have been developed (Ref. 6, 7, 8).
14
-------
In the case of airports, the methods for predicting noise exposure combine the
noise generating properties of various aircraft types with aircraft performance and
operational procedures to yield contours of equal average sound level during a spe-
cified time period. Since the basic component of average sound level is an energy
summation of sound exposure levels, the noise source descriptions for different air-
craft can conveniently be presented in terms of the sound exposure level as a function
of distance of closest approach of the aircraft during an event for different engine
power settings, e.g. takeoff, approach, ground runup.
The sound exposure level at any point on the ground, for a single aircraft opera-
tion, can be obtained by first determining the distance of closest approach from the
point of observation to the aircraft flight path, and then obtaining the sound exposure
level from data for the individual aircraft type relating sound level and distance.
The average noise level at each point of interest is obtained by adding logarithmically
the sound exposure level contributions from all aircraft operations during the time
interval of interest. (See Appendix A).
Various Government agencies use slightly different methodologies and computer
programs for predicting aircraft noise. Although the effective differences in the
results of these predictions are small, they lead to unnecessary uncertainties, mis-
interpretations and discussions. The detailed prediction procedures for the day-
night average sound level should be agreed upon and formalized as soon as possible
between all Government Agencies and other interested organizations. For air-
craft noise predictions the specific recommendations given in Appendix F. list
some of the items to be considered for incorporation into these procedures.
15
-------
The prediction accuracy of any sound Level model is no better than the accuracy of
the operational input data. In planning efforts the operational projections are not
necessarily an accurate reflection of the eventual operations. Differences in flight
paths for different aircraft, in climb performance as a function of weight, and in
atmospheric conditions all contribute to differences between predicted and measured
values of noise exposure level. These problems are common to all prediction
methodologies, however, and are not functions of the noise level measure employed.
The accuracy of average sound level predictions over a projected 24-hour operation, is
within +5 dB of the measured values, irrespective of the noise level measure; the reason
for the wide scatter range is that actual operations deviate from the projected operations.
However, the accuracy of estimated 24-hour equivalent noise levels for a set of known
operational conditions compares within +1 dB of the measured values obtained for those
operations. (Ref. 4.)
The choice of the day-night average sound level, L, , as a measure of environ-
mental noise was partly based on its relative ease of measurement. In the last
analysis, measured values of day-night average sound level taken over a long enough
period of time that a stable representation of annual daily average levels can be
obtained, are preferable to predicted values. The simplicity of the measurement of
day-night average sound level recommends it highly in this application.
COMPARISON OF DAY-NIGHT AVERAGE SOUND LEVEL WITH OTHER AIRPORT
NOISE DESCRIPTORS
A number of rating scales have been developed for airport noise analyses over
the past 20 years (Ref. 10). Those most prominent in the United States have been
the Composite Noise Rating (CNR) and the Noise Exposure Forecast (NEF). The CNR
has been used by FAA and the military services, while NEF has been used to some
extent by FAA and DOT. More recently the Community Noise Equivalent Level
CNEL) has been developed for use in the California airport noise law .(Ref. 11). A
discussion of the comparisons between these ratings and L is provided in
Appendix A and it is explained why an exact relationship between the ratings cannot
be stated.
16
-------
For comparison, however, the following relationships can be assumed,
together with the estimated range of scatter:
L, = CNEL
dn
L - NEF + 35 (± 3)
Lrf = CNR - 35 (±3)
A number of other ratings that have been developed internationally include the
British Noise and Number Index (NNI), German Stoerindex (Q), French Isopsophic
Index (N), South African Noise Index (NI), International Civil Aviation Organization
Weighted Equivalent Continuous Perceived Noise Level, WECPNL (Ref. 10). Each
of these ratings accounts for the cumulative noise exposure in a very similar way,
differing primarily in the technical details by which the noise exposure produced by
individual aircraft flyovers is described. These measures are highly intercorrelated
with NEF, CNR, CNEL, and thus with L, . (Ref. 10). Approximate conversions for
on
these measures to L can easily be derived, as they have been above for NEF and
CNR (Ref. 10).
FAA is considering the use of a rating method for airport noise termed the Air-
craft Sound Description System (ASDS). This method does not provide a measure of
cumulative noise exposure and is thus not directly comparable to the other rating
methods cited above.
THE EFFECTS OF OTHER NOISE SOURCES ON DAY-NIGHT AVERAGE LEVEL
FROM AIRPORT OPERATIONS
The definition of average A-weighted sound level given in Section 1 is inde-
pendent of the source of the noise. The average sound level in the vicinity of an
airport -will represent a Combination of the noise produced by aircraft and the noise
produced by other noise sources, e.g. motor vehicle traffic.
17
-------
The contribution of aircraft noise, relative to that from other noise sources, will
depend on the magnitude of the aircraft exposure levels, the total number of flyovers
in any time period, and the exposure levels of the other sources. Various design
charts for assessing the relative magnitudes of the contributions from these sources
are provided in Appendix A.
In most airport noise situations of interest, the contribution of aircraft noise to
the average sound level at locations near an airport will be dominant. For planning
purposes, the average sound levels due to aircraft operations should first be pre-
dicted without regard to other noise sources. Then measured or predicted average
sound levels at locations of interest in the community where other sources of noise
are expected to be predominant should be obtained. Finally, the impact of the dif-
ferent noise sources can be evaluated both individually and together.
18
-------
SECTION 3
BASIS FOR SELECTING MAXIMUM PERMISSIBLE AVERAGE NOISE LEVELS
The Noise Control Act of 1972 directs EPA to develop and publish noise criteria
that "reflect the scientific knowledge most useful in indicating the kind and extent of
all identifiable effects on the public health or welfare which may be expected from
differing quantities and qualities of noise. " This section of the report is based on re-
cent surveys of the scientific data that will support EPA's criteria document and on
preparatory work for the criteria document (Ref. 53). It is not the purpose of this
section to recapitulate these data or past efforts, which are extensively documented
in the literature (Ref. 54, 55, 21, 19), but rather to analyze how such data can be
interpreted to arrive at maximum permissible average levels with respect to the
cumulative environmental noise exposure defined in Section 1. The analysis tries to
give quantitative relationships between the average sound level to which the average
individual in a population is exposed and the resulting effects.
Although recommended values are presented here, the final choice of maximum
permissible levels is not a technical/scientific one and cannot be made by this Task
Group. Such a decision involves value judgments in the political, social, ethical and
economic domain, beyond the responsibility of the Task Group, and must be resolved
in the administrative or ultimately in the political-legal-legislative domain. However,
the following analysis indicates that the options available for setting the maximum
permissible average sound level are restricted to a range of not more than 20 dB,
no matter how the challenge "to protect the public health and welfare with an adequate
margin of safety" is interpreted.
The approach of this section will be first to present the quantitative relationship
between cumulative exposure and the risk of health effects, primarily noise induced
permanent hearing loss. Similar relationships are derived between average sound
levels and the percentage of individuals annoyed by aircraft noise, and between average
sound levels and the percentage of time that speech communication will be interrupted.
Annoyance due to noise and interference with speech communication cannot be identified
19
-------
at this time with direct disease producing health effects, but must be interpreted as
interference of the noise environment with public health and welfare according to the
intent of the Noise Control Act; certainly, according to the definition of health of the
World Health Organization, these noise effects on human activities and well being
would be included under health effects.
It must be kept in mind that the relationships between noise exposure and public
health and welfare analyzed in the following are based on statistical probabilities
rather than ^n individual cause-effect relationships. Therefore, the generalized
relationships and the recommendation of limit values are no evidence of whether any
particular individual's health is affected by the noise.
With the cause and effect relationships between human health and welfare and
cumulative noise exposure in hand, the question still remains as to what constitute,
for the purpose of this report, "significant" effects on public health and welfare. It
is reasonable, however, to require that an environment for all Americans "free from
noise that jeopardizes their health or welfare" (Noise Control Act of 1972) should have
no practically significant health effects for the most sensitive segment of the population.
This means that in terms of annoyance, speech interference, hearing considerations,
or other health effects, any noise level recommended should have no significant effect
on the majority of the people. Based on these assumptions, maximum permissible
average sound levels, L, , are recommended, one for immediate implementation
and one as long-term goal. These criterion levels are:
1. Realistic with respect to the naturally occurring background levels produced
by normal human activities, such as talking; and
2. Economically feasible, provided that an appropriate time schedule for
compliance is developed. These levels can be enforced by relatively
simple environmental noise monitoring systems.
Whether or not the numerical values recommended here are finally adopted, the
analysis framework and the quantitative relationships for the various noise effects
criteria, as presented here, should be used for discussing and characterizing the
effects of the ultimate choice of maximum permissible average sound level and to
analyze the implications of achieving such levels. Setting limits for average
environmental noise, as proposed in this report, would not eliminate the need to
protect people from occasional individual very noisy events and to restrict, by source
emission standards, the contributions of individual noise sources to the public noise
20
-------
environment. Such efforts must be pursued concurrently to the extent technologically
possible and economically feasible. Similarly the detailed characteristics of individual
noise sources, such as their pure tone contributions, must be controlled by emission/
certification standards.
Once maximum permissible average sound levels are accepted, the Federal or
local authorities must still decide how the total permissible noise dose should be
allocated between the major individual noise contributors; i.e., for example, what
percentage of the total dose should be used for aircraft noise and what percentage for
traffic noise.
Recommending upper limits of permissibility to protect the public against noise
jeopardizing their health or welfare should not be interpreted as recommending
insensitivity to the degradation with respect to noise of existing environments having
lower noise levels (e.g., National Parks or wilderness areas). In other words,
increasing noise levels to the levels of permissibility in presently quiet areas should
only be allowed if justified in the national or public interest or welfare.
HEARING LOSS
There are two important considerations in evaluating environmental noise with
respect to potential permanent hearing loss: the direct effect of environmental noise
that is loud enough to cause hearing damage, and the indirect effect of environmental
noise which, though not loud enough itself to cause damage, can still prevent recovery
of the hearing mechanism from an occupational, recreational or environmental noise
overdose- The implications of these two considerations are examined in detail in
Appendix B and are summarized in the following paragraphs.
DIRECT EFFECT
The hearing threshold for an individual at a specific frequency is determined by
measuring the level of the quietest sound that can be heard by the individual. The
amount of hearing loss at any frequency is measured by the amount by which the hear-
ing threshold has shifted upward from a previous value, or from the population norm.
Table 1 summarizes the relationship between daily noise exposure level and
maximum noise induced permanent threshold shift for the most sensitive 10 percent
of the population. The data assume 8 hours occupational noise exposure per day,
21
-------
repeated over a 40 year working lifetime. Usually, the threshold shift increases
gradually over the 40 years of exposure; the term "maximum" refers to the greatest
threshold shift occurring in this period, generally at the end.
The average of the permanent threshold shifts at frequencies of 500, 1000 and
2000 Hz, is used to define a "hearing handicap," a person is considered to suffer a
hearing handicap when his average puretone threshold for these three frequencies
exceeds by 25 dB or more the International Standards Organization (ISO) audiometric
zero (Ref. 12). The average threshold shift for these three frequencies is usually less
than that at a frequency of 4000 Hz, where the greatest change in hearing threshold
generally occurs for most types of noise. The data at 4000 Hz therefore provide a
more sensitive indicator of the noise induced permanent threshold shift than data at
lower frequencies.
Individual changes in hearing less than 5 dB are not generally considered
noticeable or significant. For instance, repeated audiograms on the same individual
will often show a 5 dB variability. Thus, the threshold of hearing damage should be
defined at the environmental noise level expected to cause a permanent threshold shift
of 5 dB at 4000 Hz in the most sensitive 10 percent of the population. From Table
1, this threshold level is seen to be an average A-weighted sound level slightly
less than 75 dB for an 8 hour exposure to broadband noise. For intermittent noises,
such as that produced by aircraft or other moving vehicles, this threshold level may
be increased by 5 dB to 80 dB, because of the opportunity for the ear to recover between
noisy events.
INDIRECT EFFECTS
Complete recovery from high levels of daily occupational or environmental noise
requires a substantial period of "quiet" with the A-weighted sound level less than 65
dB (See Appendix B). Assuming a. house noise level reduction of 15 dB, with
windows partially open, the outdoor average sound level thus should not exceed 80 dB
in order to assure that the indoor level does not exceed 65 dB.
22
-------
Table 1
Maximum noise induced permanent threshold shift in decibels, at various audiometric
frequencies, for the most sensitive 10 percent of the population, assuming a 40-year
exposure for 8 hours per day, as a function of the A-weighted average sound level of
broad-band noise. (See Appendix B for additional detail.)
A-Weighted Average Sound Level in dB**
Audiometric Frequencies (Hz)
Average shift at 500, 1, 000 and
2,000 Hz
Average shift at 500, 1, 000,
2,000 and 4,000 Hz
Shift at 4,000 Hz
75_
1
2
6
80 85
1 4
4 7
11 19
90
7
12
28
* Example: of a large number of people exposed for 8 hours per day over a 40 year work-
ing lifetime to broad band noise with A-weighted average sound level of 85 dB, the most
sensitive 10 percent of these people will exhibit, on the average, permanent threshold
shifts as follows: at a frequency of 4000 Hz, the shift will be 19 dB; the average of the
shifts at the frequencies 500, 1000, 2000 and 4000 Hz will be 7 dB; the average of the shifts
at 500, 1000 and 2000 Hz will be 4 dB.
**Add 5 dB to the average sound level for intermittent noise such as that produced by
aircraft operations.
23
-------
DAY-NIGHT AVERAGE NOISE LEVELS LOW ENOUGH TO PREVENT HEARING LOSS
Values of day-night average sound levels consistent with the above two consider-
ations are summarized in Table 2. Based on the direct effect, the recommended
upper limit of average sound level (80 dB for 8 hours outdoor exposure to intermit-
tent noise) translates to outdoor maximum permissible values of L, between SO and 86
dB, depending on the difference between the daytime and nighttime values of average
sound level. The most probable maximum permissible value for L, in an actual
environment would be 83 dB (See Appendix A, Fig. A-7).
Therefore, considering the direct effect only, an outdoor noise exposure of L , =
83 dB or less will produce no noticeable hearing change in 90 percent of the population
who are outdoors on the average as much as 8 hours per day. This group is
envisioned to include mostly young children and retired persons in warm climates,
or certain occupational situations. Since the relationship between noise exposure and
hearing in children has not been experimentally established, the criterion established
for working adults must be used. The possibility that children might be more sensi-
tive than adults to noise must be assessed when establishing what constitutes an
adequate margin of safety. The general public who are not outdoors as much as 8
hours will of course be better protected from aircraft noise. Hearing loss from noise
produced by occupational or recreational activities is not considered here, except to
note that a noise dose of 75 dB for 8 hours would be insignificant (less than a 1 dB
change in average sound level) when added to the current 90 dB (or proposed 85 dB)
average sound level that is the limit for occupational exposure 8 hours per day (Ref. 13).
The day-night average sound level determined by the "indirect effect" require-
ment for an 8 hour period of "quiet" is the same (L, - 83 dB) as found for the direct
effect, provided the 8 hours occur during daytime. However, if, as usual, the quiet
period occurs at night, the values of L are greater, ranging between 86 and 90 dB.
24
-------
Table 2
Summary of permissible values of the outdoor day-night average sound level in
decibels for intermittent aircraft noise, under two alternative constraints and for
three values of the difference between day and night values of the average sound level.
Constraint
Direct ) 8 hours outdoors in daytime
Effect i with L = 80 dB
/ eq
Require- 1
ment /
Indirect ] 8 hours indoors at night with
Effect v Leq - 65 dB indoors or 80 dB
Require- I outdoors
ment /
Difference in Day and Night Values of Out-
door Average Sound Level
0 4* 10
86** 83** 80**
86 87 90
*Mosl likely value in this range of L (See Appendix A).
'*If outside noise is steady, e. g., not composed of a series of intermittent single event
noises, such as produced by aircraft, these values should be reduced by 5 dB.
25
-------
Thus, the maximum permissible limits resulting from the direct effects of environ-
mental noise are controlling, if the "quiet" period occurs at night.
In summary, the hearing damage criteria indicate that a day-night average sound
level less than 83 dBA is required, to assure that at least 90 percent of the general
population have no measurable loss of hearing ability over the 500 to 4,000 Hz range
of frequency. Such cumulative effects of environmental noise would show up only
after exposures exceeding 10 years. This means that hearing damage data on which
to base criteria of acceptable noise exposure, or to modify the initial choice of cri-
teria, accrue very slowly. Prudence demands a conservative
approach to setting criteria in such a situation. Moreover, the 83 dB limit was
derived under certain assumptions regarding life style and exposure that might lead
to over- or underestimation of individual exposures. Therefore, in view of the
latter uncertainty, it is judged reasonable to recommend an L of 80 dB as the max-
imum permissible yearly outdoor average 'sound level, to prevent adverse health ef-
fects on people's hearing.
SPEECH COMMUNICATION
Speech communication is essential to man, both outdoors and indoors.
Outdoors
Out-of-doors, the distance between the talker and listener over which effective
speech communication can be carried on depends on both the voice level of the talker
and the level of the environmental noise that surrounds the conversants. The rela-
tionships among the different parameters are summarized below and are given in
greater detail in Appendix C.
Table 3 compares, for different degrees of vocal effort, the distance between
a talker and listener out-of-doors with the steady environmental noise level that just
permits reliable speech communication (defined as 95 percent sentence intelligibility,
i. e., 95% of the key words in spoken sentences are correctly understood by
the listener). (Ref. 49.)
26
-------
Table 3
STEADY A-WEIGHTED NOISE LEVELS THAT ALLOW COMMUNICATION WITH 95%
SENTENCE INTELLIGIBILITY OVER VARIOUS DISTANCES OUTDOORS FOR DIF-
FERENT VOICE LEVELS
VOICE LEVEL
Normal voice
Raised voice
COMMUNICATING DISTANCE (meters)
0.5 1 2 3 4 5
72 66 60 56 54 52 dB
78 72 66 62 60 58 dB
In choosing suitable limits on environmental noise to permit comfortable speech,
it appears reasonable to limit outdoor noise levels so as to permit reliable speech
communication with normal voice up to two meters separation between talker and
listener. The choice of two meters for the communicating distance is considered
reasonable for typical outside communication requirements in urban areas. To achieve
this goal the average sound level should be no greater than 60 dB, according to Table 3.
Indoors
To assess the intrusion of outdoor levels into dwellings, the criterion of distance
between talker and listener is not valid, because of the reverberant build-up of sound
by reflections from the walls of the room. For years, however, there have been
widely accepted criteria of recommended indoor noise levels appropriate to various
activities. (Ref. 57.) A reasonable criterion value, from the upper half of the range
of A-weighted sound levels recommended for living rooms (for radio and TV listening,
as well as domestic activities), hotels, motels, small offices and similar spaces
where speech communication is important, is 45 dB. A steady noise which does not
exceed this level will assure 1007 sentence intelligibility for relaxed conversation.
Assuming 15 dB noise reduction through an open window, the steady outdoor noise
level could reach 60 dB without exceeding this recommended indoor noise criterion
for residences.
27
-------
On the basis of Table 3, the same value of 60 dB is recommended as the
maximum permissible value for intruding steady noise for speech communications,
both outdoors and indoors. It is shown in Appendix C that things are changed
only slightly if these criteria are interpreted as average noise levels for
fluctuating noises, such as aircraft or traffic noise. In fact, the average noise level
is a conservative measure of noise for protection of speech communications; the
maximum permissible average sound level chosen to protect speech communication
offers somewhat less speech interference when the noise fluctuates than when it is
relatively steady.
These criteria for average sound level should apply at all times of the day when
people wish to pursue their habitual waking activities, both indoors and outdoors; that
is, they will govern the average daytime sound level (0700 - 2200). For the range of
sound level around 60 dB, the most probable value of day-night average sound level
is about 3 dB higher than the daytime average sound level. Therefore, it is concluded
that the day-night average sound level should not exceed 63 dB if people are to enjoy
their normal domestic activities indoors or to converse without difficulty outdoors at
a two meter distance.
A curve showing the complete relationship between the outdoor and indoor day-
night average sound level and percentage sentence interference is shown in Figure 2.
ANNOYANCE
The word annoyance is used in this report as a general term for reported adverse
responses of people to environmental noise. In this context not the laboratory noisiness/
annoyance studies but the studies of annoyance which are largely based on the results
of sociological surveys have been considered. Such surveys have been conducted
among residents in the vicinity of airports of a number of countries including the
United States (Ref. 14, 15, 16, 17, 56).
The results of these surveys are generally related to the percentage of respondents
expressing differing degrees of disturbance or dissatisfaction due to the noisiness of
their environments. Some of the surveys go into a complex procedure to construct a
scale of annoyance; some report responses to the direct question of "how annoying is
28
-------
LU
u
z
LU
U
Z
LU
Z
LU
LO
LU
o
z
LU
u
OUTDOORS
(NORMAL
VOICE
LEVEL AND
2 METERS
SEPARATION)
20 -
INDOORS
0
50
55 60 65 70 75 80
OUTDOOR DAY-NIGHT AVERAGE SOUND LEVEL, L , , IN DECIBELS
an
Figure 2. Maximum Percentage Interference with Sentences as a Function
of the Day-Night Average Noise Level. (Percentage Inter-
ference Equals 100 Minus Percentage Intelligibility, and L
is Based on L, + 3)
29
-------
the noise." Each social survey is related to some kind of measurement of the noise
levels (mostly from aircraft operations) to which the survey respondents are
exposed. Correlation between annoyance and noise level can then be obtained.
The results of the social surveys show that individual responses vary widely for
the same noise level. Borsky, (Ref. 18), has shown that these variances are reduced
substantially when groups of individuals having similar attitudes about "fear" of air-
craft crashes and "misfeasance" of authorities are considered. Moreover, by
averaging responses over entire surveys, almost identical functional relationships
between human response and noise levels are obtained for the whole surveyed popula-
tion as for the groups of individuals having neutralattitudinal responses.
In deriving a generalized relationship between reported annoyance and day-night
average sound level it seems reasonable to use the average overall group responses,
recognizing that individuals may vary considerably, both positively and negatively
compared to the average, depending upon their particular attitudinal biases.
An intercomparison of various survey results is presented in Appendix D, where
three of the most prominent social surveys around airports are examined. These
are the first and second surveys around London's Heathrow Airport, and the Tracer
study around eight major airports in the United States (Ref. 14, 15, 16). The noise
level data in each survey were converted to outdoor L for the purpose of this
analysis. An additional analysis was made of the overt community response for the
55 community noise situations reported in the EPA report to Congress (Ref. 19).
The relationship between the percentage of respondents who were "highly annoyed"
and the day-night average sound level is shown in Figure 3, for the combined
results of the first London survey, the Tracer study and the second Heathrow survey.
These results, based on nearly 2,000 respondents in the first London survey, and
more than 7,500 respondents in the combined surveys show an essentially identical
relationship* between the percent of people highly annoyed and the average sound
*Meaning that the regression equations are practically indistinguishable.
30
-------
80
60
o
>x
o
c
O)
~=
-------
level. The results are in complete agreement with the conclusions of a recent analysis
of British, French and Dutch survey results, conducted by the Organization for Eco-
nomic Co-Operation and Development (OECD) (Ref. 20).
As part of the Tracor analyses, a relationship was derived between the number of
people highly annoyed and the number of people who actually lodged complaints about
the noise. A scale based on this relation is also shown on Figure 3.
As a final comparison, a scale showing differing degrees of overt community
response is shown at the far right on Figure 3. This scale represents responses
to a variety of noises, not only aircraft, based on the 55-case study described in
Appendix D. On the average, adverse community reaction to noise becomes of ser-
ious concern at values of L , over 60 dB.
dn
Individual annoyance and complaint data are summarized in Table 4. The
percentage of complaints varies from 2 to 22% over the L, range of 60-80 dB, an
average rate of increase of 1% per dB. In this same range of noise levels, the rate
of increase in the percentage of people who are highly annoyed increases from 23 to
62%, an average rate of 2% per dB. However, for values of L less than 60 dB the
rate of increase in the percentage of people highly annoyed increases at a lower rate,
an average of 1%. per dB.
One may conclude that, at values of the day-night average sound level greater
than 60 dB, the rate of increase of annoyance with an increase in noise is substan-
tially greater than at lower levels, a conclusion that is also evident from the change
of slope of the curve in Figure 3.
In summary, to achieve an environment in which no more than 20% of the popu-
lation are expected to be highly annoyed and no more than 2% actually to complain
of noise, the outdoor day-night average sound level should be less than 60 decibels.
Higher noise levels must be considered to be annoying to an appreciable part of the
population, and consequently to interfere directly with their health and welfare.
32
-------
Table 4
Percentages of the population near airports who are highly annoyed and who lodge
:omplaints about noise, for various values of the day-night average sound level of
lircraft noise (from Figure 3)
Outdoor
Day- Night Average
Noise Level in dB
50
55
60
65
70
75
80
Percentage
Highly Annoyed
13
17
23
33
44
54
62
Percentage
Complainants
less than 1
1
2
5
10
15
over 20
GENERAL HEALTH EFFECTS OF NOISE
Although there is the possibility that noise of high level or extreme fluctuations
may contribute indirectly to the incidence of non-auditory diseases, no conclusive
evidence to support this possibility has been documented. Most experts agree that
there is no well-established effect of noise on health (in the more restricted sense,
i. e., the absence of disease) besides noise-induced hearing loss. A recent critical
review of this subject (Ref. 21) came to the conclusion'"if noise control sufficient
to protect persons from ear damage and hearing loss were instituted, then it is highly
unlikely that the noises of lower level and duration resulting from this effort could
directly induce non-auditory disease. "
The maximum permissible noise levels with respect to health effects on the hear-
ing organ, proposed in the section on hearing loss above, are 5 to 10 dB more protective than
the hearing conservation criteria and standards presently used by the Federal Government and
Industry (Occupational Safety and Health Act of 1970). Therefore, according to present
day knowledge, exposures to levels below the 80 dB limit recommended here should
33
-------
be considered acceptable as far as their direct contribution to non-auditory diseases
is concerned.
This is not to say that there are no indications to arouse concern in this area; but
a substantial amount of research on non-auditory effects of noise on health would be
required to alter the above statements. Such research should be fostered and the re-
sults should be carefully monitored for any evidence indicating that the maximum per-
missible average sound levels recommended herein are excessive.
Sleep disturbance due to noises is a potential indirect health effect of considerable
concern, for it can certainly affect psychological well being, irritability and mood
(Ref 21). The awakening effect of noise depends on the characteristics of the indivi-
dual person and the noise (such as time of night, age of individual, etc.). Noise
limits for sleep interference cannot yet be so clearly established as for the risk of
hearing loss or for speech interference. However, in quiet bedrooms,
sound levels below 30 dB have ordinarily no arousal effects, while steady noise above
50 dB resulted in numerous complaints.
The maximum permissible outdoor level of L =60 dB, proposed
dn
above in order to limit people's annoyance due to noise, would provide average
sound levels from exterior noise sources below 35 dB at night in an average bedroom
with closed windows. The levels in a bedroom with open windows could, of course, be
higher but it is reasonable to expect people who open their windows at night to be able
to accommodate to slightly higher levels. While individual noise events might still be
audible even in the presence of heating and air conditioning equipment, and might some-
times result in changes of sleep pattern, they would be considered for the most part
as normal and acceptable by the large percentage of the US population living in an
airport environment today. It does not appear that much would be gained by setting
the goal for day-night average sound level lower than 60 dB, for this would not neces-
sarily protect against occasional individual noise events of short duration but of high
arousal/annoyance value. The permissible day-night average sound level should not
be set unrealistically low in an attempt to account for the effects of individual events
of low probability which are not "cumulative" effects. It is recommended instead, that
maximum sound levels during the night should be controlled through separate local
noise ordinances, if desirable and necessary.
34
-------
Experience has shown (Appendix A) that, for typical traffic, airport and city
noises, when the day/night difference in the equivalent noise level is 10 dB or more,
the daytime exposure is the main concern with respect to potential speech interference
and annoyance. In these situations, a maximum permissible outdoor L. of 60 dB. will
dn
generally cause negligible speech interference or annoyance during daytime, and will
most likely cause no adverse effects on night-time sleep in normal people accustomed
to the environment, even with windows partially open.
NATURAL INDOOR NOISE "FLOOR"
An important consideration in choosing criteria of acceptable environmental noise
is the indoor noise level to be expected in residential areas irrespective of the outdoor
noise environment. It clearly makes little sense to establish criteria for external noise
sources that would lead to indoor levels lower than the "self-noise" of residential living.
While few reported data are available on the variation of noise levels within
homes housing a variety of different life styles, some limited information can be pro-
vided. The following measured values are considered representative of indoor average
sound levels where external noise intrusion is not significant, as seen in Table 5.
Table 5
,... L - dB
Condition eq
Typical people movement, no TV or radio 40 - 45
Speech at 10 feet, normal voice 55
TV listening level at 10 feet, no other 55 - GO
activity
Stereo music 50 - 70
35
-------
It should be noted that these values are average sound levels, not the maximum
sound levels, which for speech, music, and appliances can range up to 75 to 80 dB for
short durations. During sleeping hours when no appliances, TV or radio are in
operation, internally generated noise levels will be lower.
It is reasonable to conclude that in a typical quiet residential environment, values
of L between 40 and 45 due to domestic activities alone, are as low as can be
eq
expected during waking hours. There is no reason, therefore, to reduce daytime out-
door noise levels below the point where the corresponding indoor intrusion is less
than about 40 to 45 dB.
The day-night average sound level outdoors is greater than the daytime average
sound level (L ) by 0-3 dB, for differences of L and L between 10 and 4 dB,
respectively. For a typical house with open windows, the noise reduction between
indoors and outdoors is 15 dB. Therefore, the values of an outdoor L , expected to
dn
produce a daytime average sound level of 40 dB indoors are 55 to 58 dB, and those
expected to produce an indoor daytime level of 45 dB are 60 to 63 dB. These values
of outdoor L can be increased by 10 dB if the windows are closed.
dn
It is concluded that values of outdoor day-night average sound level ranging be-
tween 55 and 63 dB produce indoor daytime noise levels with open windows equal to the
natural indoor noise floor inside houses. Lowering the outdoor noise level below
fhese values would be of little value inside houses, since the natural indoor noise
floor will control the indoor noise levels.
NUMBER OF PEOPLE IMPACTED VERSUS VARIOUS GOALS FOR THE DAY-NIGHT
AVERAGE SOUND LEVEL
The most direct method of assessing the impact of environmental noise and the
implications of selecting specific levels of permissible cumulative exposure is to count
the number of people affected as a function of the value of the day-night average noise
level to which they are exposed. Table 6 summarizes the results of a preliminary esti-
mate of the number of people exposed to various levels of noise from each of the three
major sources of high level environmental noise: freeways, airports and urban traffic
in densely populated cities.
36
-------
Table 6
Estimated Number of People Exposed to Noise From Aircraft Operations, Freeway
Traffic and Urban Road and Street Traffic at Various Values of Outdoor Day-Night
Average Sound Level
Number of People in Millions
L , exceeds
dn
60 dB
65 dB
70 dB
75 dB
80 dB
Freeway
Traffic
3.1
2.5
1.9
0.9
0.3
Aircraft
Operations
16
7.5
3.4
1.5
0.2
Urban*
Traffic
18.0
7.5
3.2
0.6
0.1
Total**
37.1
17.5
8.5
2.4
0.6
*Based only on cities having populations greater than 25,000, comprising a total
population base of only 92 million.
**There may be some duplication of people in these totals.
The freeway neighborhood population estimates are based on data provided in the
EPA report to Congress (Ref. 1) and on noise level data for typical urban freeways.
The airport neighborhood population estimates are based on data in the report of the
Aviation Advisory Commission (Ref. 22) and in the EPA report to Congress (Ref 23).
The urban population estimates are based on data contained in Ref. 24 for the 92
million people living in cities having populations greater than 25,000.
The total number of persons exposed to noise from all three sources is at least
18% of the total population at an L, level of 60 dB and over 8% of the
dn
population at an L . level of 65 dB. For these levels of L. , the number of people
dn dn K H
affected by urban traffic noise is equal to or greater than the number affected by
aircraft operations in the vicinity of airports. This result is not surprising, because
an L , of 60 dB is typical throughout urban neighborhoods with detached housing in
major cities, and an L, of 65 is typical for noisy urban neighborhoods.
37
-------
The total number of persons estimated to be affected at a L, of 80 dB or more
on
is about 0. 3% of the total population, one-third of whom are affected by aircraft noise.
These persons may be subject to risk of hearing damage if they reside for many years
in such an environment.
There are three possible approaches to reducing the number of people affected by
noise. They are:
1. Reduce the noise at its source and/or restrict the number of noisy operations.
2. Increase the noise reduction in the sound paths between the source and the
people.
3. Move the people away from the noise.
Various methods for reducing aircraft noise at its source or for controlling the
number of operations and the associated economic impacts are the'subject of other
task force reports in this series. Similar assessments for reducing surface vehicle
noise at its source will be contained in future EPA documents.
With respect to the second possible approach, the noise reduction of a dwelling
may be increased by 10 to 20 decibels at a cost of approximately $3, 000 - $5, 000
respectively for a 1500 square foot detached house. (Ref. 25.) If the noise levels
within dwelling units currently exposed to outdoor levels of L, of 60 dB were to be
reduced to values comparable with an outside L of 60 dB or less by use of noise
dn
control treatment, it is estimated that the cost for these 37 million people would be
30 to 40 billion dollars. If 5 dB greater noise were allowed indoors, equivalent to an
outdoor L, of 65 dB, the estimated noise control cost would be 12 to 17 billion dol-
dn
lars for the 17. 5 million people affected. Naturally this solution would be effective
only indoors with windows closed; the outdoor environment would be unchanged. This
situation could be improved with respect to traffic noise by the use of suitable bar-
riers and acoustical absorption to supplement the exterior house wall treatment.
However, such supplementary efforts are impractical for the noise from aircraft
flight operations, and consequently, the second possibility of increased noise
reduction may never yield acceptable protection against aircraft noise heard outdoors.
38
-------
The third alternative of moving people away from the noise does not appear to be
practicable on a large scale. The direct costs for implementation greatly exceed
those estimated for noise control treatment, except where they can be offset by con-
version of land from residential to commercial or industrial uses. Such conversion
may be practical and economically feasible in the immediate vicinity of some airports.
The applicability and economic feasibility of this approach must be determined for
each local situation.
SUMMARY OF EFFECTS OF NOISE ON PEOPLE AT VARIOUS VALUES OF DAY-
NIGHT AVERAGE SOUND LEVEL
In the preceding sections the effects of noise on various human activities and
responses have been reviewed. In order to assess the implications of specifying
different values as limits for maximum permissible day-night average sound level,
the available data are summarized in Table 7.
39
-------
TABLE 7.
Outdoor Day-Night
Average Sound Level
in Decibels
re-20 micronewtons
per square meter
HEALTH EFFECTS OF NOISE AT DIFFERENT VALUES
OF OUTDOOR DAY-NIGHT AVERAGE SOUND LEVEL,
"dn1
IN DECIBELS
Hearing Risk
for Speech
in % of
Exposed People
HEARING
Percent of Exposed People
With Permanent Threshold
Shift (5 Decibels at 4000
Hertz)
SPEECH
Maximum Speech
Interference*
in Percent
OUTDOORS "INDOORS"*"
ANNOYANCE
Highly Annoyed
in % of Exposed
People
Complainants
in %of
Exposed People
50
60
70
80
90
0
0
0
4
66
0.8
2.5
53
100
100
0.1
O.T
0.1
1.5
3.2
13
23
44
62
1
2
10
20
UNKNOWN
Percentage of key words misunderstood in spoken sentences.
Normal voice effort and 2 meter separation between talker and listener. When speech interference is excessive the average communication
can be improved by reducing separation distance and/or raising voice level. For example, with an L^n of 80 dB the average interference
will not exceed 5% for a separation of 0.5 meter and raised voice level.
15 decibels noise reduction through partially opened windows, and relaxed conversational effort.
Example: When the day-night average sound level is 90 decibels outdoors:
HEARING RISK:
The percentage of people suffering a hearing handicap in a group exposed to this level of noise is expected
to be 8 percentage points higher than the percentage of people with hearing handicaps in a group, otherwise
similar, who are not exposed to noise levels of this magnitude. (This column refers only to hearing impair-
ment in the frequency range most important to understanding speech frequencies of the 500, 1000 and
2000 Hertz (cycles per second) bands.)
66% of the entire population is expected to have a noise induced permanent threshold shift greater than 5
decibels at a frequency of 4000 Hertz (cycles per second).
SPEECH INTERFERENCE:
For conversation outdoors, the percentage of key words misunderstood in spoken sentences will be 100%,
and for conversation indoors, 3.2% "Maximum Speech Interference" here refers to conditions of
continuous steady noise; the speech interference would be less for intermittent noise and substantially
less for infrequent intermittent intrusions corresponding to the same value of Day-Night Average Sound
Level.
ANNOYANCE:
The number of noise exposed people who are highly annoyed and the number who are expected to complain
about the noise are unknown for this level of exposure, but they are greater than 62% and 20%, respectively,
which are the values appropriate to an outdoor LrJn of 80 decibels.
-------
SECTION 4
CONCLUSIONS AND RECOMMENDATIONS
Conclusions
The Task Group arrived at the following conclusions:
1. For the characterization of the cumulative impact of noise environments on
human health and welfare a single noise measure is required for use by the
Federal Government. This measure must be the same for all types of noises
so that the contributions of various types of noise source to the total environ-
mental exposure can be identified.
2. Evaluation of existing and proposed methods available for the description
of environmental noise leads to recommendation of the day-night A-weighted
average sound level as the method of choice. The method is described in
detail in Section 1; it can be related to other more complicated methods
in use for special applications as discussed in Appendix A. The method has
the following advantages:
It is relatively simple.
It can be used for the prediction of noise environments in land use plan-
ning studies as well as for the measurement and economical monitoring
of existing noise environments.
, A-weighted sound level has been shown to correlate well with the various
effects of noise on people.
The method has the following shortcomings:
To evaluate the effect of noise on human annoyance, better weighting func-
tions than A-weighting may be possible (for example, a D-type weighting).
However, the evidence is not conclusive and no network for such weighting
has yet been standardized.
41
-------
The method does not account for pure tone components or for impulsive
character in the noise. These noise characteristics have a definite
influence on the annoyance value of some aircraft noise (for example,
compressor noise and helicopter noise). Neglecting these characteristics
in the proposed measure makes their control by other means necessary
(emission/certification standards). None of these shortcomings is con-
sidered serious enough to justify delay in adopting a common measure.
It is emphasized that this measure of day-night average sound level is
not intended for use in determining compliance of product noise with
specifications or individual source noise certification.
3. To specify maximum permissible noise exposure with respect to human
health and welfare, the selected measure must be used not only to describe
the noise environment of a given location; but must be extended to
describe the noise environment to which individuals and populations are
exposed during their 24-hour living routines. This leads to the concept of
the average sound level to which individuals and populations are exposed as
the only reasonable and defensible primary measure for limiting human
exposure to noise. The average sound level depends on the noise to which
individuals are exposed, indoors and outdoors, at home, at work, in school,
etc. Human exposure, as assessed by this primary measure, can therefore
be controlled not only by controlling the average sound level of the outdoor
environment but also by modifying the noise reduction effected by buildings.
The measure gives a clear and objective basis for land use planning and
for zoning and can take into account changes in climate, life style, etc.
4. The measure of day-night average sound level (L ) can be used to predict
the effects on a population of the average long term exposure to environment
noise. These relationships, as outlined in Section 3 for noise induced per-
manent hearing loss, interruption of speech communication, and individual
annoyance, should be used for choosing maximum permissible average sound
42
-------
levels. Compliance with the maximum permissible average sound level
can be monitored by relatively simple and available instrumentation.
5. To avoid significant long-term effects of environmental noise on human
hearing (i.e., to avoid any effect after 10 years in at least ninety percent
of the population) requires an average outdoor L < 83 dB* according to
dn
strict application of current scientific test data. A reasonably conservative
choice of a criterion of acceptable exposure would be L < SO dB. Other
dn
permanent or disease producing health effects cannot yet be quantitatively
correlated with cumulative exposure.
6. An outdoor L , of approximately 60 dB or less is required in order that no
dn
more than 239< of the population exposed to noise would be individually highly
annoyed. (The same average sound level would guarantee that, on the average.
95% effective speech conversation at two meters distance outdoors would be
possible at all times, and normal domestic speech activities are possible
indoors, with open windows.) It therefore appears reasonable to propose an
L of 55 to 60 dB as the long range goal for maximum permissible average
sound level with respect to health and welfare. (Note that this level is not con-
sidered optimum, merely the upper limit of permissibility. No endorsement is
intended of degradation of existing areas having a lower noise level. ) Adoption
of such a goal must be examined in terms of the overall context of the Noise Control
Act of 1972, including the effects of such a choice on the total public welfare of
the nation.
7. According to the estimates in the Table 5, a goal of Ldl
-------
the average noise level to this limit would reduce the percentage of people
annoyed by occasional noise events or at occasional times during their life
(Section 3). An environment in which not even a small percentage of the
population will be annoyed by some noise events a small percentage of the
time appears to be a Utopian and unrealistic goal. The disturbance by individual
noise events and occasional high noise levels should be controlled by maximum
permissible noise levels for individual events established by local authorities.
Control over such events should not be attempted by lowering the average sound
level.
8. The absence of a pure-tone penalty in the basic measure for average sound
level (See 2 above and Section 1) is based on the assumption that pure tone
components are primarily to be controlled by emission control standards.
As long as such standards are not effective or in cases where, for technologi-
cal or other reasons, significant pure tone components remain, it is advisable
to consider them in the detailed prediction/land use planning procedure. The
effective perceived noise level methodology (CNR and NEF) is adequate for
this. However, to arrive at the day-night average sound level, which can be
validated by measurements and compared to other noise exposures, such data
must be approximated by the average sound level as described in Section 2.
For environments where pure tones are known to be present, local authorities
should lower the recommended maximum permissible day-night average
sound level by 2 to 5 dB. Monitoring of average sound level is then possible
with the same simple instrumentation. (Situations where this procedure
might be advantageously applied are the approach area of military jets having
no pure-tone intake noise control, or helicopter noise exposures, and others.)
9. In summary, it is a realistic goal to keep the day/night average sound level
below 60 dB in residential areas, where the average includes a 10 decibel
penalty on nighttime noise levels. In conjunction with noise emission stand-
ards and local control of individual noise events, such a limit is expected to
insure, according to present knowledge, a noise environment without signi-
ficant effect on public health and welfare.
44
-------
RECOMMENDATIONS
The task group recommends the following actions:
1. The Environmental Protection Agency and other Federal Agencies should
adopt as soon as possible, the day-night A-weighted average sound level as
the measure for environmental noise. At such time as a suitable "D-type
weighting" becomes standardized and available in commercial instruments.,
its value as a weighting for environmental noise should be considered, to
determine whether or not it should replace the A-weighting recommended here.
2. For the aircraft noise study and aircraft noise standards required by the Noise
Control Act of 1972, the recommended measure should be used to identify levels
of cumulative noise exposure and to study the implications of achieving specific
levels of permissible cumulative noise exposure. It should be used for cost
benefit studies, planning, monitoring and enforcement.
3. The prediction procedures for day-night average sound level from aircraft
operations, ground traffic and other major noise sources should be standard-
ized in all details for uniform use by all Government Agencies. Although the
differences in procedures used by DOT, DOD, HUD, and in the California
airport noise law are small, and the effects of these differences on the
final exposure prediction are minor, these differences will continue to be used
as excuses against the practical implementation and enforcement of the day-
night average noise level. There is no good technical or other rea.sr
to have a detailed standardized method. (See Section 2.)
4. Predictions for land-use planning purposes of day-night aver? j level
from aircraft operations should not consider the noise fror jources
in the initial analysis. On the other hand, development o. agulatory
actions based-on day-night average sound level must consider the contribu-
tions, if any, of other noise sources to the values of L at any point in the
community.
5. To protect the public health and welfare against the risk of any measurable
permanent noise induced hearing loss, with adequate margin of safety, and
45
-------
to protect the public against completely unacceptable amounts of annoyance
and speech interference, a yearly outdoor day-night average sound level of
80 decibels in residential areas should, as soon as possible, be promulgated
as the permissible limit. Exceptions to this maximum permissible noise
level must be based on zoning regulations and/or building codes that will
assure a maximum average sound level (not day-night average!) of the occu-
pants (allowing for a reasonable combination of indoor and outdoor exposures,
based on the expected living styles of the community) not exceeding 75 dB.
6. A yearly day-night average sound level of 60 dB or below should be the long range
limit of the EPA for environmental noise quality in residential areas with
respect to health and welfare. For specific situations local authorities may
prescribe lower noise levels, particularly for areas that have a quieter en-
vironment now, and for which there is no planned requirement in the public
interest to allow noise levels to increase to the maximum permissible level.
Exceptions to the outdoor L < 60 dB may be based on zoning regulations,
building codes and/or expected lifestyles, provided the indoor L predicted
to reach the individual ear from environmental (not produced by the individual)
noise is less than 45 dB.
7. The time schedule for implementation of the L , < 60 dB goal with respect to
aircraft noise should be based on detailed economic and technological feasi-
bility studies, and should agree with a similar schedule to reach this goal
with respect to other noise sources, such as traffic noise. To achieve this
goal, public understanding must be raised of the noise exposure problem, the
proposed measure of noise exposure, the noise exposed zones and the per-
missible noise levels with respect to health and welfare.
46
-------
REFERENCES
1- "Report to the President and Congress on Noise, " Environmental Protection
Agency, NRC 500. 1, December 31, 1971.
2. D. E. Bishop, "Judgements of the Relative and AbS'- ^.ceptability of Air-
craft Noise, " J. Acoust. Soc. Am. 40, 103, Deceju. j.
3. K. D. Kryter, "The Effects of Noise on Man," Academic Press, New York,
1970.
4. W. J, Galloway, "Review of Land Use Planning Procedures," Interim Techni-
cal Report, Aerospace Medical Research Laboratory, W-PAFB, Ohio, March
1972.
5.
"House Noise - Reduction Measurements for Use in Studies of Aircraft Flyover
Noise," Society of Automotive Engineers, Inc. AIR 1081, October 1971.
6. D. E. Bishop and R. 0. Horonjeff, "Procedures for Developing Noise Exposure
Forecast Areas for Aircraft Flight Operations," FAA Report DS-67-10, August
1967.
7. "Procedure for Describing Aircraft Noise Around an Airport, " ISO Recom-
mendation R507, 2nd edition, International Standards Organization, June 1970.
8. C. G. von Niekirk and J. L. Muller, "Assessment of Aircraft Noise Distur-
bance, " J. Roy. Aer. Soc. 73, 383 - 396 (1962).
9. "Standard Values of Atmospheric Absorption as a Function of Temperature and
Humidity for Use in Evaluating Aircraft Flyover Noise Signals, " Society of
Automotive Engineers, Inc., ARP 866, 1964.
10. W. J. Galloway and D. E. Bishop, "Noise Exposure Forecasts: Evolution,
Evaluation, and Land Use Interpretations," FAA Report NO - 70 - 9, August
1970.
11. "The Adopted Noise Regulations for California Airports, Title 4, Register 70,
No. 48-11-28-70. Subchapter 6. Noise Standards.
R-l
-------
12. "Standard Reference Zero for the Calibration of Pure-Tone Audiometers," ISO
Recommendation R-389, International Standards Organization.
13. Occupational Safety and Health Act of 1970, Section 1910. 95.
14. "Noise-Final Report," Cmnd. 2056, H.M.S.O. London, July 1963.
15. "Second Survey of Aircraft Noise Annoyance around London (Heathrow) Airport,"
H.M.S.O., London, 1971.
16. "Community Reaction to Airport Noise - Vol. 1," Tracer Inc. , NASA CR-1761,
July 1971.
17. C. Bitter, "Noise Nuisance Due to Aircraft," Collogue sur la definition des
exigences humain a 1' egard du bruit, Paris, November 1968.
18. P. N. Borsky, "A New Field-Laboratory Methodology for Assessing Human
Response to Noise," NASA CR-2221, March 1973.
19. K. M. Eldred, "Community Noise," Environmental Protection Agency NTID
300.3, December 1971.
20. "Social and Economic Impact of Aircraft Noise, " Sector Group on the Urban
Environment, Organization for Economic Co-Operation and Development,
April 1973.
21 "Effects of Noise on People," Environmental Protection Agency NTID 300.7,
December 1971.
22. "Aircraft Noise Analyses for the Existing Air Carrier System," Bolt Beranek
and Newman Inc. , Report 2218, September 1972.
23. "Transportation Noise and Noise from Equipment Powered by Internal Com-
bustion Engines, " Environmental Protection Agency, NTID 300.13, December
1971.
24. "1970 Census of Population," PC(P3)-2, U. S. Department of Commerce,
November 1970.
25. "House Soundproofing Pilot Project for the Los Angeles Department of Air-
ports," Wyle Laboratories Report Number WCR-70-1, March 1970.
R-2
-------
26. Blirck, W. , M. Grutzmacher, F. J. Meister, E. A. MUller, and K. Matschat,
"Fluglarm, Gutachten erstattet im Auftrag des Bundesministers fiir
Gesundheitswesen" (Aircraft Noise: Expert Recommendations Submitted under
Commission from the German Federal Ministry for Public Health), Gottingen,
1965.
27. Bruckmayer, F. andJ. Lang, "Storung der Bevolkerung durch Verkehrslarm"
(Disturbance of the Population by Traffic Noise), Oesterreiche Ingenieur-
Zeitschrift, Jg. 1967, H. 8, 302-206; H.9, 338-344; and H. 10, 376-385.
28. Bruckmayer, F., and J. Lang, "Storung durch Verkehrslarm in Unterrichtsraumen
(Disturbance Due to Traffic Noise in Schoolrooms), Osterreichische Ingenieur-
Zeitschrift, 1_1 (3): 73-77 (1963).
29. "Schallschutz: Begriffe" (Noise Control: Definitions), TGL 10 687, Blatt 1
(Draft), November 1970, Deutsche Bauinformation, East Berlin.
30. "Mittelung zeitlich schwankender Schallpegel (Aquivalenter Dauerschallpegal)"
(Evaluation of Fluctuating Sound Levels (The Equivalent Continuous Sound
Level), DIN 54 641, (Draft) April 1971, Deutsche Normen, Beuth-Vertrieb
GmbH, Berlin 30.
31. "Schallschutz: Territorial und Stadtebauliche Planung" (Noise Control: Land
Use and City Planning), TGL 10 687, Blatt G, (Draft) November 1970, Deutsche
Bauinformation, East Berlin.
32. "Schallschutz in Stadtebau" (Noise Control in City Planning), DIN 18 005,
(Draft) August 1968, Deutsche Normen, Beuth-Vertrieb GmbH, Berlin 30.
33. Benjegard, Sven-Olaf, "Bullerdosimetern" (The Noise Dose Meter), Report
51/69, Statens institut fur byggnadsforskning, Stockholm, 1969.
34. Stevens, K. N. and Pietrasanta, A. C., and the Staff of Bolt Beranek and
Newman Inc. , "Procedures for Estimating Noise Exposure and Resulting
Community Reactions from Air Base Operations," WADC TN-57-10, Wright-
Patterson Air Force Base, Ohio: Wright Air Development Center, 1957.
35. Robinson, D. W. and Miss J. P. Cook, NPL Aero Report No. Ac 31, June
1968, National Physical Laboratory, England.
36. Meister, F. J., "Der Einfluss der Einwirkdauer bei der Beschallung des
Ohres" (The Influence of the Effective Duration in Acoustic Excitation of the
Ear), Larmbekampfung _!() (3/4), June/August 1966.
R-3
-------
37. Pearsons, K. S. "The Effects of Duration and Background Noise Level on Per-
ceived Noisiness, " FAA ADS-78, April, 1966.
38. Galloway, W. J., and Dwight E. Bishop, "Noise Exposure Forecasts: Evolu-
tion, Evaluation, Extensions and Land Use Interpretations" Bolt Beranek and
Newman Inc., Report No. 1862, August 1970; also FAA-No-70-9.
39. "Procedure for Describing Noise Around an Airport, " R-507. International
Standards Organization, Geneva, 1970.
40. "Noise Assessment with Respect to Community Noise" R-1996, International
Standards Organization, Geneva, 1970.
41. "Assessment of Noise-Exposure during Work for Hearing Conservation, "
R-1999, International Standards Organization, Geneva, 1970.
42. W. Passchier-Vermeer, "Hearing Loss Due to Steady-State Broadband Noise,"
Report No. 35, Institute for Public Health Engineering, The Netherlands, 1968.
43. D. W. Robinson, "The Relationships Between Hearing Loss and Noise Exposure,"
Aero Report Ae 32, National Physical Laboratory, England, 1968.
44. W. L. Baughn, "Relation Between Daily Noise Exposure and Hearing Loss as
Based on The Evaluation of 6835 Industrial Noise Exposure Cases, " In publica-
tion as AMRL-TR-73-53, Wright-Pater son Air Force Base, Ohio.
45. H. M. Carder and J. D. Miller, "Temporary Threshold Shifts From Prolonged
Exposure to Noise," J. of Speech and Hearing Research, 15, 603-623, 1972.
46. J. H. Mills and S. A. Talo, "Temporary Threshold Shifts Produced by Exposure
to Noise, "J. Speech and Hearing Research, 15, 624-631, 1972.
47. W. Melnick, "Investigation of Human Temporary Threshold Shift (TTS) From
Noise Exposure of 16 Hours Duration, " paper presented at meeting of
Acoustical Society of America, 1972.
48. "Occupational Exposure to Noise, Criteria for a Recommended Standard, "
U. S. Dept. of Health, Education, and Welfare, 1972.
49. J. C. Webster, "Effects of Noise on Speech Intelligibility," Noise as a Public
Health Hazard, American Speech and Hearing Association No. 4, February,
1969.
R-4
-------
50. "Methods for the Calculation of the Articulation Index, " ANSI 53. 5-1969,
American National Standards Institute, New York.
51. "Community Noise Measurements in Los Angeles, Detroit, and Boston," Bolt
Beranek and Newman Inc., Report No. 2078, June 1971.
52. W. Dixon Ward, "The Concept of 'Effective Quiet'", presented at the Eighty-Fifth
Meeting of the Acoustical Society of America, April 1973.
53. International Conference on "Public Health Aspects of Noise" at Dubrovnik,
Yugoslavia, May 1973, sponsored by the EPA. Proceedings to be published.
54. Alleviation of Jet Aircraft Noise Near Airports. A report of the Jet Aircraft
Noise Panel. Office of Science and Technology, Executive Office of the President
'March 1966).
55. Public Hearings on Noise Abatement and Control. Vol VII, Physiological and
Psychological Effects, US EPA, 1971.
56. H. O. Finke, R. Guski, B. Rohrmann, R. Schnemer and A. Schuemer-Kohrs,
"An Interdisciplinary study on the effects of aircraft noise on man. " in
reference 53.
57. L. L. Beranek, W. E. Blazier, and J. J. Figwer, "Preferred Noise Criterion
(PNC) Curves and Their Application to Rooms," J. Acoustical Society of America,
Vol. 50, 1223-1228, 1971.
58. J. E. Parnell, D. C. Nagel and A. Cohen, "Evaluation of Hearing Levels of
Residents Living Near a Major Airport, " Report No. FAA-RD-72-72, Dept. of
Transportation, Washington, D. C., 1972.
59. "A Basis for Limiting Noise Exposure for Hearing Conservation, " EPA-550/
9-73-001-A or AMRL-TR-73-90. July 1973.
60. Johnson, D. L., "Prediction of NTPTS due to Continuous Noise Exposure, "
EPA-550/9-73-001-B or AMRL-TR-73-91, July 1973.
R-5
-------
APPENDIX A
JUSTIFICATION OF THE USE OF THE AVERAGE SOUND LEVEL AS A
MEASURE OF COMMUNITY NOISE
PROBLEMS TO BE RESOLVED IN CHOOSING A NOISE MEASURE
NEED FOR A SIMPLE AND PRACTICAL RATING SCHEME
All efforts to alleviate noise pollution must finally rest on the means for describ-
ing the magnitude of the noise problem as it affects human beings. To assess the
present noise exposure, to establish criteria for an acceptable noise environment, to
limit the noise output of especially prominent sources of disturbance all these goals
demand the adoption of a rating scheme, such that a numerical evaluation of the noise
(preferably in terms of a single number) will bear a meaningful relation to the amount
of public disturbance caused by the noise. Thus, we look for ways to measure the
physical properties of the community noise exposure that are closely connected with
people's subjective judgment. We measure, with acoustical test equipment, certain
aspects of the noise that, either alone or in combination, can be used to predict
accurately how people will respond to the noise.
The question of what and how much to measure is important in choosing a mea-
sure to characterize community noise, largely because of the economic implications
of the cost of making measurements. It is more expensive to make "complicated"
measurements than "simple" ones. Thus, for a given measurement budget, one can,
for example, mount a more extensive survey, covering a greater area of the com-
munity, if the data to be taken are relatively simple. Of course, recent technological
advances in logic circuitry have made it possible to make certain relatively complex
measurements routinely and simply. It is a question of choosing between the ultimate
refinement in measurement techniques and a practical measurement approach that is
no more complicated than is needed to predict the impact of noise on the people, and
that can be extensively applied at a reasonable cost.
A-l
-------
FREQUENCY ANALYSIS OF THE NOISE AND THE A-WEIGHTED SOUND LEVEL
One of the most useful ways to characterize a noise is by a frequency analysis,
because people not only distinguish the high-frequency components from the low-
frequency components in a composite noise, but they find high frequency noises much
more annoying than low-frequency noises of the same level. Therefore, to evaluate
how disturbing each noise will be, we should know how much of the sound energy in
that noise is contained in each band of frequency. This means keeping track of an
entire set of frequency-band sound levels for each noise: as many as nine different
numbers for octave-band data, or twenty-five different numbers for 1/3 octave band
data, to cover the important frequency range from 31 to 8000 Hz.
Fortunately, much of this complication can be avoided by the use of a special
electrical weighting network in the measurement system, that simulates the response
of the average human ear to sounds of different frequency: each frequency of the noise
then contributes to the total reading an amount approximately proportional to the sub-
jective response associated with that frequency. Measurement of the overall noise
with a sound level meter incorporating such a weighting network yields a single num-
ber such as the A-weighted Sound Level, or simply sound-level, in decibels.
For zoning and monitoring purposes this choice marks an enormous simplifica-
tion and a significant economy. For this reason, A-weighted Sound Level has been
adopted without exception in large-scale surveys of city noise coming from a variety of
sources. It is universally accepted as an adequate way to deal with the ear's differing
sensitivity to sounds of different frequency. The magnitude aspect of a noise can then
be handled in terms of greater or smaller sound-levels.
NOISE ABATEMENT AND SIMPLE RATINGS
The dominant characteristic of environmental noise is that it is not steady at
any particular location the noise usually fluctuates considerably, from quiet at one
instant to loud the next. Thus, we cannot simply say that the noise level at that loca-
tion is "so-many decibels. " To describe the noise exposure completely requires a
A-2
-------
statistical approach. Consequently, we should speak of the "noise exposure" at a
location, meaning the whole time-varying pattern of sound levels. Such a noise
exposure can be described by giving the complete curve depicting the cumulative
distribution of sound levels, showing exactly what percent of the whole observation
period each level was exceeded.
A complete description of the noise exposure would distinguish between daytime,
evening and night time, and between week-day and week-end noise level distributions;
it would also give distributions to show the difference between winter and summer,
fair weather and foul.
The practical difficulty with the statistical methodology is that it yields a large
number of statistical parameters for each measuring location; and even if these were
averaged over more or less homogeneous neighborhoods it still would require several
numbers to characterize the noise exposure in that neighborhood. It is literally im-
possible for any such array of numbers to be effectively used either in an enforce-
ment context, for the purpose of noise abatement or to map out existing noise
exposure base lines.
It is essential therefore, to look further for a suitable single-number evaluation
of community neighborhood noise exposure. Note that the ultimate goal in noise
abatement is to characterize with reasonable accuracy the noise exposure of whole
neighborhoods (within which there may actually exist a fairly wide range of noise
levels) so as to prevent extremes of noise exposure at any given time, and to detect
unfavorable trends in the future noise climate. For these purposes, pinpoint accuracy
and masses of data for each location are not required, and may even be a hindrance,
since one could fail to see the forest for the trees.
A noise measure must be found that collapses the array of statistical parameters
described above into a single usable figure for describing the noise exposure of a
neighborhood, even if that simplification entails some compromise with the current
standard of highest attainable accuracy.
A-3
-------
AVERAGE SOUND LEVEL
The average sound level, sometimes called the equivalent continuous noise level
(both having the symbol L ) is the continuous sound-level that is equivalent, in terms
of noise energy content, to the actual fluctuating noise existing at the location over the
observation period.* The Equivalent Continuous Noise Level was developed in Germany
over a period of years and was introduced in 1965 as a rating specifically to evaluate
9 fi
the impact of aircraft noise upon the neighbors of airports . It was almost immedi-
ately recognized in Austria as appropriate for evaluating the impact of street traffic
OO QQ
noise in dwellings , and in schoolrooms . It has been embodied in the National
29 30
Test Standards of both East Germany and West Germany for rating the subjective
effects of fluctuating noises of all kinds, such as from street and road traffic, rail
traffic, canal and river ship traffic, aircraft, industrial operations (including the
noise from individual machines), sports stadiums, playgrounds, etc. It is the rating
31 32
used in both the East German and West German standard guidelines for city plan-
ning. It was the rating that turned out to correlate best with subjective response in
the large Swedish traffic noise survey of 1966-67. It has come into such general use
in Sweden for rating noise exposure that commercial instrumentation is currently
available for measuring L directly; the lightweight unit is small enough to be held in
eq 23
one hand and can be operated either from batteries or an electrical outlet .
During the period when the L rating was coming into wide acceptance in Europe,
eq
there was little familiarity with it in this country, because the relevant literature was
not available in English. One exception was the use of the concept of equivalent level
in the 1957 original Air Force Planning Guide for noise from aircraft operations .
A more recent application is the development of the CNEL (Community Noise
Equivalent Level) measure for describing the noise environment of airports. This
measure, contained in the Noise Standards, Title 4, Subchapter 6, of the California
Administrative Code (1970) is based upon a summation of L over a 24 hour period
with weightings for exposure during evening and night periods.
*L is read "L-equivalent".
eq
A-4
-------
RELATED APPLICATIONS OF THE ENERGY EQUIVALENCE CONCEPT
The concept of representing a fluctuating noise level in terms of a steady noise
having the same energy content is widespread in recent research. There is solid
experimental evidence that it accurately describes the onset and progress of permanent
35
noise-induced hearing loss , and considerable evidence to show that something very
3fi
much like it applies to annoyance in various circumstances . The concept is approxi-
37
mately borne out by Pearson's experiments on the trade-off of level and duration of
a noisy event, and by numerous investigations of the trade-off between number of
38
events and noise level in aircraft flyovers . Indeed, the Composite Noise Rating
38
currently in use by the FAA is a formulation of L , modified by corrections for
day vs. night operations, etc. The concept is embodied in several recommendations
39
of the International Standards Organization, for assessing the noise from aircraft ,
40 41
industrial noise as it affects residences , and hearing conservation in factories.
AVERAGE SOUND LEVEL AND ITS RELATIONSHIP TO OTHER NOISE MEASURES
EXPRESSIONS FOR AVERAGE SOUND LEVEL
The basic definition of L , apart from the nighttime penalty, is formulated in
terms of the equivalent steady noise level, L , that in a stated period of time would
contain the same noise energy as the time-varying noise during the same time period.
That is,
L 1/2
°SL = i / £_ dt
10 10 "'a-'l J t p*
In many applications it is useful to have analytic expressions for the average sound
level L in terms of simple parameters of the time-varying noise signal, so that the
integral does not have to be computed. It is often sufficiently accurate to approximate
a complicated time-varying noise level with simple time patterns. For example,
A-5
-------
industrial noise can often be considered simply in terms of a specified noise level that
is either on or off as a function of time. Similarly, individual aircraft or motor
vehicle noise events can be considered to exhibit triangular time patterns that occur
intermittently during a period of observation. (Assuming an aircraft flyover time
pattern to be triangular in shape instead of shaped like a "normal distribution function"
introduces an error of, at worst, 0. 7 dB). Other noise histories can often be approxi-
mated with trapezoidal time pattern shapes.
The following sections provide explicit analytic expressions for estimating the
average sound level in terms of such time patterns, and graphic design charts are pre-
sented for easy application to practical problems. Most of the design charts are ex-
pressed in terms of how much (AL) the level of the new noise source exceeds an
existing background noise level, L . This background noise may be considered as the
existing (that is, before the introduction of the new noise) average sound level, pro-
vided that its fluctuation is small relative to the maximum value of the new noise level.
CONSTANT LEVEL NOISE STEADY OR INTERMITTENT
The L for a continuous noise having a constant value of L is
eq max
L
_T max
Leq = 101°SlO T L° 10 dt =
When L is intermittently on during the time period T, for a fraction, x, of the
max
total time, with a background noise level Lfe present for the time (1-x), L is given by
Leq " Lb + 101°g10
(dB) (A-2)
where AL = L - L, . This expression is plotted in Figure A-l for various values
max b
A-6
-------
of AL and x. It can be seen from the figure that, for values of L that are 10 dB or
0 max
more higher than L , L is approximated quite accurately by:
L = L +10 log x
eq max
(dB) (A-3)
Triangular Time Patterns
The average sound level for a single triangular time pattern having a maximum
value of L and rising from a background level of L, is given by:
max ° fa b n y
L = L, + 101og,n ~
eq b °10 2,3AL
(10 10 - 1) (dB) (A-4)
where again AL - L - L, . When A L is greater than 10 dB. the following approxi-
0 max b '
mation for L is quite accurate:
eq
T im 2.3AL
L = L - lOlog-
eq max "10 10
(dB) (A-5)
The value of L for a series of n identical triangular time patterns having maximum
eq oc-t,
levels of L , and durations measured between (L - 10 dB) points of T seconds,
max max
and a background level of L . occurring during a total time period T, is given by:
L = L. + 101og
eq b "
AL
i-^ {10 10 -i
[ 1 l 2.3
AL )
" 10 J
(dB) (A-6)
A design chart for determining L for different values of AL as a function of n T per
hour is provided in Figure A-2.
A-7
-------
An approximation to equation (I-G) for cases where AL is greater than 10 dB is
given by:
L = L v + 101°&rfe (dB) (A-7)
eq max ^. o 1
Trapezoidal Time Patterns
The average sound level, L , for a trapezoidal time pattern having maximum
eq
level of L , background level of L, . duration between (L - 10 dB) points of T.
max' ° b max
and duration at L of £ is given by
max
^
10 10 .i-lL Lu x
AL
2.3 v10""-1; ^io io i
10 2
(dB) (A-8)
The approximation to L when AL is greater than 10 dB, for £ small compared
to T, is:
L = L - ^ + 10 log £ (dB) (A-9)
eq max 10
Noting the similarity between equations (A-3), (A-5), and (A-9), one can
approximate L for a series of trapezoidal pulses by suitably combining design data
from Figure A-l and A-2. That is, the approximate L for a series of n trape-
eq
zoidal pulses is obtained by the L value for triangular pulses plus an additional term
equal to 10 log^ n£, e.g.,
L = L +10login ~= + lOlog nf (dB) (A-10)
eq max 10 2.31 iu
A-8
-------
Time Patterns of Noise Having a Normal Statistical Distribution
Many cases of noise exposures in communities have a noise level distribution that
may be closely approximated by a normal statistical distribution. The average sound
level for the distribution can be described simply in terms of its mean value, which for
a normal distribution is L. , and the standard deviation, s, of the noise level
50
distribution:
Leq = L50
A design chart showing the difference between L and L as a function of the standard
deviation is provided in Figure A-3.
It is often of interest to know which percentile level of a normal distribution is
equal in magnitude to the L value for the distribution. A chart providing this rela-
tionship as a function of the standard deviation of the distribution is provided in Figure
A-4.
Various noise criteria in use for highway noise are expressed in terms of the L
value. For a normal distribution, the L value is specified in terms of the median
and standard deviation by the expression L.^ = L A + 1.28 s. The difference between
10 50 2
L and L is given by L - L = 1.28 s - 0.115 s . This expression is plotted as
J.U 6C[ J.U GQ
a function of s in Figure A-5.
It should be noted that traffic noise does not always yield a normal distribution of
noise levels, so caution should be used in determining exact differences between L
eq
andL1().
COMPARISON OF L , AND L . , AND OTHER NOISE MEASURES
e dn
Relationships Between L and EPNL For Aircraft
e
Basic certification measurements for aircraft subject to FAR Part 36 certification
rules are reported in Effective Perceived Noise Level (EPNL) in dB. These values
A-9
-------
differ from the L based on sound level-A primarily due to the difference in frequency
weighting of the sound pressure levels. No unique relationship exists for the numeri-
cal difference between L and EPNL, the actual difference being a function of the
spectral shape of the sound. Further, EPNL has a provision for assessing a numeri-
cal penalty for the presence of pronounced tonal components in the spectrum, while
L does not.
e
The numerical differences between EPNL and L are thus a function of aircraft
e
type, engine power setting and distance from the aircraft, since air absorption changes
with distance affect the spectral shape of the noise signal. In general, EPNL will be
numerically greater than L . Typical values of this difference, for takeoff power
6
settings, are from 1 to 5 dB. The differences at approach power settings range typi-
cally from 2 to 8 dB.
Comparison of L , with Composite Noise Rating (CNR), Noise Exposure Forecast
(NEF), and Community Noise Equivalent Level (CNEL).
CNR, NEF, and CNEL are all currently used expressions for weighted, accumu-
lated noise exposure. Each is intended to sum a series of noises, frequency weighting
their sound pressure levels, and then adding nighttime penalties. The older ratings,
CNR and NEF, are expressed in terms of maximum Perceived Noise Level and Effec-
tive Perceived Noise Level, respectively; each considers a day-night period identical
to LJ .
dn
The measure CNEL iteself is essentially the same as L except for the method
of treating nighttime noises. In CNEL the 24-hour period is broken into three periods:
day (0700-1900), evening (1900-2200), and night (2200-0700). Penalties of 5 dB are
applied to the evening period and 10 dB to the night period. For most time distribu-
tions of aircraft noise around airports, the numerical difference between a two-period
and three-period day are not significant, being of the order of several tenths of a
decibel at most.
A-10
-------
One difference between these four similar measures is the method of applying
the nighttime weighting and the magnitude of the penalty. The original CNR concept,
carried forward in the NEF, weighted the nighttime exposure by 10 dB. Because of
the difference in total duration of the day and night periods, 15 and 9 hours respec-
tively, a specific noise level at night receives a penalty of 10 + 10 log (-r^ or
'10 X9
approximately 12 dB in a reckoning of total exposure. Given the choice of weighting
either exposure or level, it is simpler to weight level directly, particularly when
actual noise monitoring is eventually considered.
There is no fixed relationship between L or CNEL and CNR or NEF, because
of the differences between the A-level and PNL frequency weightings and the allow-
ance for duration, as well as the minor differences in approach to day /night considera-
tions. Nevertheless, one may translate from one measure to another by the following
approximate relationship :
LJ = CNEL = NEF + 35 = CNR - 35
dn
For most circumstances involving aircraft flyover noise these relationships are valid
within about a ±3 dB tolerance.
Comparison of L with HUD Guideline Interim Standards (1390.2 chg. 1).
The interim HUD standards for outdoor noise are specified for all noise sources,
other than aircraft, in terms of A-weighted sound level not to be exceeded more than
a certain fraction of the day. Aircraft noise criteria are stated in terms of NEF or
CNR.
The HUD exposure criteria for residences near airports are "normally acceptable"
if NEF 30 or CNR 100 is not exceeded. A "discretionary acceptable" category permits
exposures up to NEF 40 or CNR 115.
For all other noise sources the HUD criteria specify a series of acceptable, dis-
cretionary and unacceptable exposures. Since these specifications are similar to points
on a cumulative statistical description of noise levels, it is of interest to compare the
A-ll
-------
HUD criteria with L for different situations. For discussion purposes, consider
eq
the boundary between the categories "discretionary-normally acceptable" and
"unacceptable. "
The first criterion defining this boundary allows A-weighted noise levels to exceed
65 dB up to 8 hours per 24 hours, while the second criterion states that noise levels
exceeding 80 dB should not exceed 60 minutes per 24 hours. These two values may
be used to specify two limit points on a cumulative distribution function. The relation-
ship between L and the HUD criteria may then be examined for different types of
eq
distribution functions, restricting the shape of the distribution only so that it does
not exceed these two limit points.
First consider two cases of a normal distribution of noise levels, comparable to
vehicle traffic noise. For the first case, assume a distribution with quite
narrow variance so placed on the graph that the 65 dB point is not exceeded (see
Fig. A-6). For this curve, to the nearest decibel, L = 64 dB, and the corresponding
ou
standard deviation (arbitrarily chosen small) is 2.3 dB. The resulting L is equal
eq
to 64.6 dB.
Now consider a normal distribution with the widest permissible variance (the
curve marked Maximum Variance in Figure A-6); if the variance were any greater,
the distribution would violate HUD's requirement that the level not exceed 80 dB for
more than 60 minutes per 24 hours. This distribution, to the nearest decibel, has
L =60 dB, L = 74 dB, and a standard deviation of approximately 11 dB. The
o\) 10
resultant L =74 dB, is almost 10 dB higher than for the previous case. Both curves
eq
meet HUD's interim standards.
Next, consider a series of intermittent high level noises, superposed on a typical
urban/suburban background noise level, such that 80 dB is not exceeded more than 60
minutes per 24 hours, say 4%. Choosing a series of repeated triangular-shaped time
signals of 90 dB maximum sound level will produce an L value of 72.4 dB without
exceeding an L value of 80 dB.
A-12
-------
However, one can allow the maximum level to increase indefinitely provided that
L remains at 80 dB or less. The limiting case is that of a square-shaped time pattern,
4
switched on and off. In this instance, if the total "on-time" is 4% or less, the value
of L is equal to L - 14 dB, and both L and L can increase without limit
and still remain acceptable within the HUD interim standards. Maximum A-levels
for an aircraft can be as high as 110 dB, which would permit L values of 96 to be
obtained without exceeding the L limit of 80 dB.
It is clear that no unique relationship can be specified between the HUD non-
airport standards and L . Values of L ranging up to 95 dB can be found in com-
eq eq
pliance with the HUD outdoor noise standard depending on the time distribution of
noise levels considered. Even if the night-time penalty were applied to L to yield
eq
L, there would still be no unique relation with the HUD standards.
dn
Comparison of LeC) with Federal Highway Administration Noise Standards,
PPM 90-2, February 8. 1973
The primary criteria of PPM 90-2 are that L for noise levels inside people-
occupied spaces shall not exceed 55 dB, or for sensitive outdoor spaces "in which
serenity and quiet are of extra-ordinary significance, " 60 dB.
Highway noise characteristically yields a random distribution of noise level,
the distribution function being approximately normal in many instances. In this case,
the relationship between L and L is given by the expression:
eq iu
L = L - 1.28 s + 0.115 s2
eq 10
where s is the standard deviation of the noise level distribution. The difference be-
tween L and L for normal distribution of sound level is plotted in Figure A-5.
It can be noted that L = L - 2 dB within ±2 dB, for s ranging from 0 to 11 dB.
Highway noise rarely has a standard deviation of 11 dB; 2 to 5 dB is more typical.
Thus, setting L at 60 dB for highway noise impacting a sensitive outdoor
space, we find that an L value of GO -2 = 58 + 2 dB would meet the most sensitive
eq
FHWA criterion.
A-13
-------
Relationship of Leq with the Proposed FAA Aircraft Sound Description System (ASDS)
FAA is considering the adoption of ASDS for use as an airport noise descriptor.
Basically, ASDS defines the extent of noise exposure, for each aircraft type, in terms
of the area defined by the maximum A-weighted sound level, per aircraft event, equal
to 85 dB, and a time constant per aircraft type and operation that provides a weighting
based on the duration during which the level at various areas within the 85 dB contour
exceeds 85 dB. While specific time constants are derived for different aircraft types,
it is assumed that a 15 second duration could often be used as a nominal value for
takeoff operations and 10 seconds for approach operations.
A second part of the ASDS is the computation of the Situation Index (SI) which is
a linear summation of areas and durations obtained over all operations to obtain the
quantity "acre-minutes."
The ASDS concept does not allow any direct comparison to energy equivalents
except on the 85 dB boundary, since both sound level and duration vary continuously
on either side of the boundary. The only comparison that can be made is the relation-
ship between single event values of L at the boundary. For this case, L is approxi-
e e
mately 98 dB on takeoff and about 93 to 95 dB on approach.
Using the above relationships, the L or L values for a succession of identical
events could be computed at points on the ASDS contour boundary. If different air-
craft types are involved, no way exists to compare the total exposure unless the con-
tours are identical. The ASDS approach is not amenable to determining cumulative
noise exposure level at an arbitrarily selected point around an airport.
COMPARISON OF DAYTIME AND NIGHTTIME AVERAGE SOUND LEVELS WITH L
dn
The choice of a nighttime weighting factor should consider the normal variation
between daytime and nighttime values of average sound level, abbreviated here as L
and L , respectively. One way to consider this variation is to compare the difference
between L , and L , as a function of L , , for a range of values of L and for different
d n' dn' dn
types of noise situations.
A-14
-------
Data from 63 sets of measurements were available in sufficient detail that such
a comparison could be made. These data are plotted in Figure A-7. The data
span noise environments ranging from the quiet of a wilderness area to the noisiest
of airport and highway environments. It can be seen that, at the lowest levels (L
around 40-55 dB) L, is the controlling element in determining L, , because the
nighttime noise level is so much lower than that in the daytime. At higher L
levels (65-90 dB), the values of L are not much lower than those for L ,; thus because
v ' n d
of the 10 dB nighttime penalty, L will control the value of L, .
n on
The choice of the 10 dB nighttime penalty in the computation of L has the follow-
ing effect. In low noise level environments, the natural drop in L values is approxi-
mately 10 dB, so that L, and L contribute about equally to L However, in high
an an
noise environments, the night noise levels drop relatively little from their daytime
values. In these environments the nighttime penalty applies pressure towards a
"round-the-clock" reduction in noise levels if the noise criteria are to be met.
The effect of a nighttime penalty can also be studied indirectly by examining the
correlation between noise measure and observer community response in the 55 com-
munity reaction cases presented in the EPA report to Congress (Ref. 1). The data
have a standard deviation of 3.3 dB when a 10 dB nighttime penalty is applied, but
the correlation worsens (std. dev. =4.0 dB) with no nighttime penalty. However,
little difference was observed among values of the penalty ranging between 8 and 12
dB. Consequently, the community reaction data support a penalty of the order of 10
dB but they cannot be utilized for determining a finer gradation. Neither do the data
support "three period" in preference to "two-period" days, in assigning non-daytime
noise penalties.
A-15
-------
0.01
1.0
Fraction of Time L On
max
Figure A-l. L for Intermittent L Added to L,
eq max b
-------
>
I
10
nT per hour In seconds
TOO
1000
Figure A-2. L for a Repeated Series of n Triangular Signals Overlaid on a Background Level
eq
of L, dB andT= Duration at L -10 dB in Seconds
b max
-------
16
12
03
-u
c
o
10
4 6 8
s - Standard Deviation in dB
10
12
Figure A-3. Difference between L and L._n for a Normal Distribution
eq 50
Having a Standard Deviation
A-18
-------
<£>
10
20
30
40
50
6 8
s in dB
10 12
14
Figure A-4. Percentile of a Normal Distribution that is Equal to L
eq
-------
i
to
o
CQ
-o
r
-2
\
4 6 8 10
s - Standard Deviation in dB
12
14
Figure A-5. Difference Between LIO and L for a Normal Distribution
-------
99.99
O
O
-------
to
tSS
CQ
3^0
c C
.<
^ ,
c
_l '
" t>
"S o)
J Tl
U
c
M
t/> -»~
tE.1
0
^ UJ
1
E £
_c
x.2>
0 Z
?n
1 Q
1 O
16
14
12
10
8
6
4
2
0
1 1 i 1 1 1 I I 1
0
"
0
9
Approx. o *
"~ Curve -,
_]_ ° o %
A Rural /Wilderness
O Residential, Light Traffic
Residential, Heavy Traffic
Dense Residential
D City, Commercial
> Railroad
V Airport
T Freeway
"""
_\ Q ^ ^^ n
^V/V.
-A *C*\ D
0 n \ Q V
o \ o.
o o >. *
0 ^*
^ ^,
0 o ° "T T
~~ o * a v ~
I 1 1 1 L 1 1 1 1
40 45 50 55 60 65 70 75 80 85 90
Day-Night Average Sound Level, L , -dB
Figure A-7. Comparison of the Difference Between Day and Night Values of the Equivalent Sound
Level with the Day-Night Average Sound Level, L
-------
APPENDIX B
HEARING LOSS EXPECTED FOR VARIOUS LJ VALUES
dn
There are two important considerations with respect to the health effects of en-
vironmental noise. The first is the amount of hearing change that results when the
environmental noise level is high enough to cause direct hearing damage. The second
is the extent to which environmental noise, at a level not high enough to cause direct
damage, may yet prevent recovery of thehearing mechanism from an occupational or
recreational noise over-exposure. Both considerations will be explored for typical
environmental exposures in the next two paragraphs.
1. Tables B-l and 2 summarize the direct hearing changes expected from
exposures to various values of day-night.average sound level, L .
(a) Explanation of terms in Table B-l.
Four different measurement parameters are considered in Table B-l.
These are:
(1) Max NIPTS: Noise Induced Permanent Threshold Shift (NIPTS) is
the permanent change in hearing threshold directly attributable to
noise. The NIPTS for a person increases with his exposure duration,
and Max NIPTS is the maximum value during a 40-year noise exposure
that starts at age 20. The entries in this row apply to the most sen-
sitive 10% of the population. Thus, the entries on this row signify
that 90% of the population are expected to have less Max NIPTS than
this value.
(2) NIPTS at 10 years. The entries on this row also apply to the most
sensitive 10% of the population; thus 90% of the population are expected
to have less Max NIPTS than this value.
B-l
-------
TABLE B-l
SUMMARY OF THE PERMANENT HEARING DAMAGE EFFECTS
EXPECTED FOR CONTINUOUS NOISE EXPOSURE AT
VARIOUS VALUES OF THE A-WEIGHTED AVERAGE
SOUND LEVEL (ref 59)
75 dB for 8 hrs
Max NIPTS (Most Sensitive 10',',')
NIPTS at 10 yr (Most Sensitive 10','i)
Average NIPTS
Max Hearing Risk
Max NIPTS (Most Sensitive 10S)
NIPTS at 10 yr (Most Sensitive 10(,'i)
Average NIPTS
Max Hearing Risk
Max NIPTS (Most Sensitive 10%)
NIPTS at 10 yr (Most Sensitive 10<«)
Average NIPTS
Max Hearing Risk
Max NIPTS (Most Sensitive 10^
NIPTS at 10 yr (Most Sensitive
Average NIPTS
Max Hearing Risk
Speech (. L>
1 dB
0
0
K/A
Speech (.5
1 dB
1
0
rA
,1,2) Speech (.5.1
2 dB
1
0
N/A
80 dB for 8 hrs
, 1,2) Speech (.0,1.
4 dB
3
1
N/A
,2,4) 4kH/
(i dB
fl
1
N /A
,2,4) 4101 z
11 dB
9
4
N/A
85 dB for S hrs
Speech (.5,1,2) Speech (.5.1,2,4)
4 dB
2
1
12S
7 dB
6
3
X /A
19 dB
10
9
N/A
90 dB for S hrs
Speech (.5,1,2) Speech (. 5.1.2.4) 4kil2
7dB
4
3
22. 3£
12 dB
9
6
N/A
28 dB
24
15
N/A
Example: For an exposure of 85 dB during an 8-hour working day, the following effects
are expected:
In the most sensitive 10% of the population, the Max NIPTS occurring during a 40-
year working life-time, averaged over the four speech frequencies of 0.5, 1, 2 and !
kHz, is 7 dB; averaged over the three frequencies of 0. 5, 1 and 2 kHz, the expected max.
NIPTS is only 4 dB; the Max shift at 4 kHz is 19 dB. For this same most sensitive 10',-,
of the population, the expected NEPTS after only 10 years of exposure would be 6 dB
averaged over the four speech frequencies, '2 dB averaged over three frequencies, and
16 dBat 4kHz.
The NIPTS averaged over the entire population and over a 40-year working life-time
is 3 dB averaged over four frequencies, 1 dB averaged over three frequencies, and 9 dB
at 4 kHz.
And finally, out of the entire population, the percentage of people in a group exposed
to this noise who have NIPTS greater than 25 dB, averaged over the three speech fre-
quencies, would be 12 percentage points greater than expected in an otherwise similar
group who are exposed only to levels of occupational noise significantly lower than 85
dB.
B-2
-------
(3) Average NIPTS. The NIPTS averaged both over a 40 year exposure
duration and over all the population. This figure differs by only a
couple of decibels from the median NIPTS after 20 years of exposure
for the entire population.
(4) Max Hearing Risk. Hearing risk is defined as the difference between
the percentage of people with a hearing handicap in a noise-exposed
group and the percentage of people with a handicap in a non-noise
exposed (but otherwise equivalent) group. A person is said to have
a hearing handicap if the average of his threshold shifts at the three
audiometric frequencies 0.5, 1, and 2 kHz exceeds 25 dB. The
hearing risk increases with the duration of the noise exposure and
the Max Hearing Risk is defined as the highest value of hearing risk
that occurs during 40 years of exposure.
(b) Derivation and explanation of Table B-l
(1) Derivation of NIPTS. Three different predictive methods were used
to derive the values of Table B-l. These are the reports of
42 43 44
Passchier-Vermeer , Robinson and Baughn . The NEPTS
values of Table B-l present an arithmetical average of the results
of all three methods. The hearing risk values are an arithmetical
average of Robinson's and Baughn's predictions (See ref 59, 60).
(2) Other Audiometric Frequencies. Table B-l does not contain
entries for all the audiometric frequencies commonly used in hearing
tests; however, for most typical noises, 4 kHz is the most sensitive
frequency, since the greatest NIPTS typically occurs at this frequency.
A noise that does not cause excessive hearing change at this frequency
will not normally cause a greater change in the other frequencies
from 3000 - 10,000 Hz.
B-3
-------
(3) Significance of the various hearing changes depicted in Table B-l.
75 dB for 8 hours: With one exception, the changes noted are less
than normal audiometric error (+5 dB) and would not normally be
perceived, even in the most sensitive 10% of the population. The
exception is the 6 dB loss at 4 Hz for the most sensitive 10% of the
population. The conclusion is that an exposure at a sound level of 75
dB (8 hours a day) corresponds to the threshold of measurable noise
induced changes in hearing ability of the general population. Such an
exposure is not considered hazardous to public health.
80 dB for 8 hours; As with the previous level, there are no signi-
ficant hearing changes at speech frequencies. At 4 kHz, however,
measurable changes in individual acuity for at least 109c of the popu-
lation occur. It is estimated that 8 hour exposures to an L of 80
eq
dB will cause some hearing changes, especially of the higher audio-
metric frequencies such as 4 kHz, but that these predicted losses
are of marginal significance.
85 dB for 8 hours: The NIPTS expected for speech frequencies is
still less than 5 dB and, as such, is still not reliably measurable
on an individual. The Maximum Hearing Risk, however, is slightly
greater than 10%. That is, 10% more people in the noise-exposed
group have average threshold shifts greater than 25 dB when com-
pared to those in the group not exposed to as much as 85 dB during
the 8 hour working day. Thus, L of 85 dB for 8 hours causes a
noticeable shift in hearing ability of the general population. The
NIPTS at 4 kHz likewise begins to assume substantial proportions.
Ten percent of the population will have NIPTS greater than 15 dB
after 10 years exposure. The average, or even more resistant ears,
according to Baughn's data, will show more than a 5 dB loss. In
summary, at 85 dB for 8 hours there will be significant changes in
hearing ability in the general population.
B-4
-------
90 dB for 8 hours; The maximum change (7 dB) in the three-
frequency speech hearing level for 10% of the population exceeds
5 dB for this SPL. Maximum Hearing Risk is slightly above 20%.
This is 10 percentile points more than recommended by the ISO
standard. Expected NEPTS at 4 kHz is large for all the population
and is clearly very significant. Therefore it is considered that L
of 90 dB for 8 hours (85 dB for 24 hours) will produce a significant
change in hearing ability that will be unacceptable to the general
population under any circumstances.
(c) Derivation and Explanation of Table B-2
(1) Derivation of Table B-2
The derivation of Table B-2 was the same as B-l, except that the hearing
risk data from Table XV of the National Institute for Occupational Safety
and Health (NIOSH) criteria document are also included (ref 48).
(2) Explanation of Table B-2.
Table B-2 is included in order to show the relationship between
exposure level and the percentage of persons showing a measurable
hearing change (greater than 5 dB Noise Induced Permanent Thresh-
old Shift) at 4kHz. (ref 60)
For Hearing Risk, linear interpolation was used to estimate the
Hearing Risk values between 80 and 85 dB as well as between 85 and
90 dB, from Table B-l.
2. Corrections Required to Convert 8 hour Exposures to Noise Into Day-Night
Average Sound Levels
a. The use of L (which embodies the equal-energy concept) is a conserva-
tive approach with respect to hearing conservation. Even for a steady
continuous noise, the Temporary Threshold Shift (TTS) is not predictable
on a log linear basis for all possible time durations. The equal-energy
B-5
-------
TABLE B-2
EXPECTED HEARING CHANGES FOR VARIOUS A-WEIGHTED AVERAGE
SOUND LEVELS IN dB
Exposure Level
L
eq
L^ *
dn
Percent of Population with NDPTS
Greater than 5 dB at 4 kHz
Hearing Risk from Table B-l
Speech (.5,1,2 kHz) from NIOSH
72
80
4
0
0
75
83
15
0
0
80
88
44
5
3
82
90
66
8
8
85
93
92
12.5
15
*Valid for Fluctuating Noise such that Lj = L + 8dB
& dn eq
method predicts with reasonable accuracy the TTS at 4 kHz for durations
from 8 hours to 30 minutes. Durations shorter than 15 minutes, however,
are better predicted by a method which allows a 6 dB increase per halving
of duration. The TTS for speech frequencies is predicted by a 5 dB
increase/halving of duration. In summary, the effects of intermittent
noises which are 15 dB or more greater than the 8 hour exposure average
sound level (L ) are predicted too high. For a two minute exposure,
the SPL required to produce the expected TTS of 4 kHz would have to be
approximately 10 dB (20 dB for speech frequencies) higher than that
predicted by the equal-energy concept. This conservatism, which is
inherent in an energy-average method, applied to noises which fluctuate
significantly in level, will be considered in the intermittency correction.
b. The 24 Hour Extrapolation
Exposures longer than 24 hours are not considered more noxious than
24 hour exposures because studies of Temporary Threshold Shift
45 46 47
(TTS) ' ' have shown that, for exposure to a specific noise level,
B-6
-------
TTS will not exceed a limiting value regardless of exposure duration.
This limit is reached approximately at 24 hours of exposure. The same
studies show that the TTS after 24 hours of exposure generally exceeds
the TTS after 8 hours of exposure 5 dB or less. Thus the use of a 5 dB
correction factor is suggested to correct the measured data for 8 hour
exposure to apply to 24-hour exposure. For example, the predicted
effects of a noise exposure of 75 dB for a 24 hour duration are equiva-
lent to the effects estimated from industrial studies for an 8 hour exposure
to a continuous noise with a level of 80 dB. This 5 dB correction is con-
sistent with the equal-energy trade/off between exposure duration and
noise level; that is, if the equal-energy rule is used to estimate the
effects for 24 hour exposure, based on 8-hour exposure data, the cor-
rection factor between 8 hours and 24 hours is again 5 dB.
c. Intermittency
In practice, the noise to which people are exposed seldom remains
continually at the same level; instead, the noise fluctuates or is inter-
mittent. There is ample proof that intermittent noise is less harmful
than continuous noise with the same L . Page VI-17 to VI-23 of the
48 6q
1972 NIOSH criteria document contain a good resume of the effect of
intermittent noise, and such a discussion will not be repeated here. In
summary, however, intermittent noise whose peak levels are 5 to 15
dB higher than continuous noise may still produce equal hearing damage.
Investigations of typical noise patterns from the EPA document "Com-
19
munity Noise" indicate that in typical environmental noise situations
involving aircraft operations, the noise is very intermittent. For this
reason, the L measured near airports can be expected to produce
eq
less harmful effects than those depicted in Table B-l. Some correc-
tion factor is thus required for L values describing noise exposure
composed largely of aircraft noise, or other noises of intense, but
B-7
-------
intermittent nature. Assuming that the noise level between events is
less than 65 dB for at least 10 percent of the time, a 5 dB correction is
suggested. This may be low, but justification of a larger correction
would require more detailed analysis and data than were available for
this report,
d. Contribution of the Indoor Noise Environment to total Exposure
A person's 24-hour exposure will typically include both outdoor and
indoor exposures. Since a building reduces the level of most intruding
environmental noises by 15 dB or more (windows partially open), an
outdoor L will not adequately predict hearing effects, because the
corresponding NIPTS estimates will be too high. Estimates based on
indoor L will likewise be too low. Consider a situation where the aver-
eq
age sound level is 80 dB outdoors and 65 dB indoors. The effective
noise exposure reaching the ear for some of the possible exposure
situations are:
24-hour L in dB
eq
Combined
Indoor Time
(65 dB)
24hrs
23
22
21
20
16
8
0
Outdoor Time
(80 dB)
0 hrs
1
2
3
4
8
16
24
Indoor &
Outdoor
65.0
68.6
70.5
71.8
72.9
75.5
78.3
80
Outdoor
Only
-
66.2
69.2
71.0
72.2
75.2
78.2
80
(assuming 0 dB for
the indoor time;
i.e. , ignoring its
contribution to
the total exposure)
The 24-hour value of the combined L is essentially unchanged from
the outdoor value (less than one dB) by the indoor noise exposure, so
B-8
-------
long as the outdoor exposure exceeds 3 hours. Thus, as long as the
criterion is established with respect to outdoor noise exposure exceeding
3 hours per day, the contribution of the indoor noise environment may
be neglected in computing the 24 hour L . This conclusion does not de-
eq
pend greatly on the actual noise attenuation provided by the house so
long as the attenuation is greater than 10 dB.
e. Values of the Day-Night Average Sound Level
It has been concluded that an A-weighted average sound level (L ) of
eq
80 dB for 8 hours daily exposure corresponds to the threshold of mea-
surable hearing change in the general population. This threshold includes
a 5 dB correction to allow for intermittency in the noise events, a value
that is appropriate for aircraft noise operation. Adoption, as a criterion,
of a maximum permissible outdoor average sound level for an 8 hour
daily exposure should protect those persons that have the greatest outdoor
activity, including young children, and retired persons living in warm
climates, and people in certain outdoor occupations. The general public,
who are not outdoors for as much as 8 hours per day, will be better
protected.
The values of L corresponding to an A-weighted average sound level of
80 dB during daytime hours, range between 80 and 86 dB. The lower
value corresponds to a situation where the average sound level during
the night is 10 dB lower than that occurring during the day, whereas the
higher value corresponds to the situation when the average sound level
during the night equals that occurring during the day. The most probable
difference between the daytime and nighttime values of L is 4 dB, as
eq
shown for the noise levels of interest in Fig. A-7 of Appendix A.
For this day-night difference, L, is three decibels above the daytime
dn
value of L , or 83 dB. This value of 83 dB is considered to be the most
eq'
probable value of L, to be found in real environments that have a day-
dn
time L of 80 dB.
eq
B-9
-------
3. Basis for the "Quiet" Requirement for the Noise Exposed Population
Recent research by Ward (Reference 52) has shown that the quiet intervals be-
tween high intensity noise-bursts must be below GO dB SPL for the octave band
centered at 4 kHz, if recovery from the Temporary Threshold Shift (TTS) is
to be independent of the quiet period SPL. A sound pressure level of 55 dB
in the 4 kHz octave band is suggested as a goal for "effective quiet", based
on the following assumptions: (1) TTS recovery from a 90 dB (8 hr) occu-
pational exposure also requires a 55 dB level of effective quiet in the 4000
Hz band for some part of the 16 hrs before another exposure the following
day, (2) total TTS recovery is required to prevent TTS from becoming
NIPTS, and (3) 8 hours in the nighttime period is a reasonable minimum
recovery time. For typical spectra of community noise, the requirement
for 55 dB sound pressure level in the 4 kHz octave band translates to an
A-weighted sound level indoors of 65 dB, or more. The house noise reduc-
tion of 15 dB for windows partially open allows the outdoor A-weighted sound
level to be 80 dB, to achieve an indoor level of 65 dB. The values of day-night
average sound level corresponding to an A-weighted average sound level of
80 dB during night-time range between 86 and 90 dB, depending of the differ-
ences between daytime and nighttime average sound levels. For a difference
of 4 dB, the most probable value, the value of L is 87 dB.
4. Supporting Studies
In the preceding sections of this Appendix the relationship of environmental
noise to hearing level was based on the application of known relationships
between noise exposure and hearing which primarily come from Industrial
exposures. There is only one study available which attempts to directly
relate actual community aircraft noise exposure to changes in hearing level.
In 1970 the Department of Transportation supported a study (ref. 58) of the
hearing levels of a sample population taken from an area (Playa del Rey)
next to the Los Angeles Airport as opposed to a sample taken from a nearby
relatively nonexposed area. The authors of the report stated that from this
B-10
-------
study it was not possible to draw firm conclusions about the effects of the
community aircraft noise exposure since results showed only small differ-
ences between the mean hearing level of the groups. At the low frequencies
on the audiograms, the direction of these differences was equivocal, but at
the high frequencies there were trends suggesting poorer hearing for the
airport area residents. The average time spent in the Playa del Key location
by the test subjects was 9-17 years. The L of the exposed area was not
dn
given, but using the raw data available in the report and the methodology of
Appendix A, the L can be estimated to be in the range of 80-83 dB. Using
dn
this range of values, the results of this study are not inconsistent with the
effects predicted by this Appendix in that a L of 83 dB is presented as the
threshold of measurable effects for more than 90% of the population after
20-40 years of exposure. Using Table B-l, the average NIPTS for a L of
83 dB (8 hour exposure of 75 dB) should be negligible (approximately 1 dB or
less dependent on frequency) for exposures even longer than those exper-
ienced by the Playa del Key community. The results of the Playa del Rey
study, therefore, are exactly what should be expected if L =83 dB is at
dn
or close to the true threshold of hearing changes.
B-ll
-------
APPENDIX C
SPEECH COMMUNICATION
Speech communication has long been recognized as an important requirement of
any human society. Interference with speech communication disrupts one of the chief
specific distinctions of the human species, disturbs normal domestic activities,
creates a less desirable living environment, and can sometimes, for those reasons,
be a source of extreme annoyance.
Noise can disturb speech communication in a variety of situations encountered at
work, in transportation vehicles, at home, etc. Of chief concern for the purposes of
this report, however, is the effect of noise on speech communication at home, for
face-to-face conversation indoors or outdoors, telephone use, and radio or television
enjoyment.
The extent to which noise of the community affects speech communication around
the home depends on the location (whether indoors or outdoors), the amount of noise
attenuation provided by the exterior walls of the house (including windows and doors)
and the vocal effort of the talkers. Certainly it is possible to maintain communication
in the face of intruding noise if the voice level is raised; but in an acceptable noise
environment one should not have to increase the voice level above a normal, comfor-
table effort in order to communicate easily.
SPEECH INTERFERENCE DUE TO NOISE
Research over a number of years since the late 1920's has made great progress
in characterizing quantitatively the effects of noise on speech. A review of that work
is contained in Refs. 21 and 49, and is summarized here.
C-l
-------
The chief effect of intruding noise on speech is to mask the speech sounds and
thus reduce intelligibility. The important contributants to intelligibility in speech
sounds cover a range in frequency from about 200 to 6000 Hz, and at each frequency a
dynamic level range of about 30 dB.
The intelligibility of speech will be nearly perfect if all these contributions are
available to a listener for his understanding. To the extent that intruding noise masks
out or covers up some of these contributions, the intelligibility deteriorates: more
rapidly the higher the noise level, particularly if the noise frequencies coincide with the
important speech frequencies.
It is no accident, from the evolutionary point of view, that the hearing of humans
is most sensitive in the frequency range most important for understanding their
speech. Therefore, it is not mere coincidence that the A-weighting, designed to
imitate the frequency sensitivity of the human ear, should also be useful as a measure
of the speech interference potential of intruding noise. A-weighting gives greatest
v/eight to those components of the noise that lie in the frequency range where most of
the speech information is compressed, and thus yields higher readings (A-weighted
levels) for noises whose energy is concentrated in that frequency range.
For these reasons the results of rather complicated research studies can be
easily simplified and summarized in terms of A-weighted sound levels, as shown in
Figure C-l. This figure presents the distances between talker and listener for
satisfactory conversations outdoors, in different steady background noise levels
(A-weighted), for three degrees of vocal effort. This presentation depends on the
fact that the voice level at the listener's ear (outdoors) decreases at a predictable
rate as the distance between him and the talker is increased. In a steady background
noise from the community, there comes a point, as the talker and listener increase
their separation, where the decreasing speech signal is first equalled and then masked
by the noise.
C-2
-------
90,
CN
E
X,
Z
a
o
CN
4)
w
CO
HI
4)
u
i
a.
c
o
.3 .4
.6 .8 1 1.5 2 34 6 8 10
Communicating Distance In Meters
15 20
Figure C-l. Maximum Distances Over Which Conversation is Considered to be
Satisfactorily Intelligible (Sentence Intelligibility = 95% Except as
Noted) (refs 19 and 49)
C-3
-------
The levels plotted in the figure do not permit perfect sentence intelligibility at the
indicated distances; instead, the sentence intelligibility at each distance is 95 percent,
meaning that 95 percent of the key words in a group of sentences would be correctly
understood. 95 percent speech intelligibility permits reliable communication, because
of the redundancy in normal conversation. That is, in normal conversations, many
unheard words can be inferred since they occur in a particular and often familiar con-
text; often the vocabulary is restricted which helps understanding. Therefore, 95 per-
cent intelligibility is adequate for most situations.
Other factors, such as the talker's enunciation, the familiarity of the listener
with the language, and the listener's motivation, also influence the intelligibility;
but the plotted data are valid under average conditions.
The data of Figure C-l are tabulated for convenience below:
Table C-l
STEADY A-WEIGHTED NOISE LEVELS THAT ALLOW COMMUNICATION WITH 95
PERCENT SENTENCE INTELLIGIBILITY OVER VARIOUS DISTANCES OUTDOORS
FOR DIFFERENT VOICE LEVELS (ref 49)
COMMUNICATING
VOICE LEVEL DISTANCE (meters)
0.5 1 2 3 4 5
Normal voice 72 66 60 56 54 52 dB
Raised voice 78 72 66 62 60 58 dB
If the levels in Figure C-l and Table C-l are exceeded, the talker and
listener must either move closer together or expect reduced intelligibility. For
example, suppose a conversation at a distance of 3 meters in a steady background
noise of 56 dB using "normal voice" levels. If this background level were increased
from 56 to 66 dB, the talkers would either have to move from 3 to 1 meter separation
C-4
-------
to maintain the same intelligibility, or alternately, to raise their voices well above
"raised voice" effort. If they remain 3 meters apart without raising their voices,
the intelligibility would drop from 95 to 65 percent (this last conclusion is not
deducible from the figure).
INDOOR SPEECH COMMUNICATIONS
The research results concerning the masking of speech sound out-of-doors are
not valid indoors, because they depend on a predictable decrease of speech sound with
increasing distance between talkers; the predictable relation is upset indoors because
of reflections from the walls and other boundaries of the room.
Fortunately, however, there are well-known criteria of long-standing for accep-
table noise levels indoors, appropriate to various indoor activities. These are
tabulated in terms of A-weighted sound levels in Table C-2.
Note that the range of recommended A-levels for indoor spaces typical of dwel-
lings (items 6-8) is from 34 to 47 dB, but for spaces used mostly during the day
where speech communications are important (items 7 and 8) the emphasis is on levels
between 38 and 47 dB. A typical recommended level from the upper half of this latter
range is 45 dB. This level will allow relaxed, face-to-face conversation with essen-
tially 100% sentence intelligibility for all locations of talker and listener in a typical
room in a dwelling.
Assuming 15 dB of attenuation through a partially opened window, the steady
outdoor noise level could reach 60 dB without exceeding the recommended indoor
noise criterion of 45 dB for residences. With lower outdoor levels, the interior
noise environment would shift toward the more favorable end of the recommended
range listed for items 6 to 8 in Table C-2, leading to improved speech communi-
cations conditions.
C-5
-------
Table C-2
ACCEPTABLE STEADY SOUND LEVELS FOR VARIOUS
TYPES OF SPACES AND USES (from ref 57)
Type of space (and acoustical requirements)
1. Concert halls, opera houses, and recital halls (for listen-
ing to faint musical sounds)
2. Broadcast and recording studios (distant microphone
pickup used)
3. Large auditoriums, large drama theaters. and churches
(for excellent listening conditions)
4. Broadcast, television, and recording studios (close
microphone pickup only)
5. Small auditoriums, small theaters, small churches.
music rehearsal rooms, large meeting and conference
rooms (for good listening), or executive offices and
conference rooms for 50 people (no amplification)
6. Bedrooms, sleeping quarters, hospitals, residences.
apartments, hotels, motels, etc. (for sleeping, rest-
ing, relaxing)
7. Private or semiprivate offices, small conference rooms,
classrooms, libraries, etc. (for good listening condi-
tions)
8. Living rooms and similar spaces in dwellings (for con-
versing or listening to radio and TV)
9. Large offices, reception areas, retail shops and stores,
cafeterias, restaurants, etc. (for moderately good
listening conditions)
10. Lobbies, laboratory work spaces, drafting and engineer-
ing rooms, general secretarial areas (for fair listening
conditions)
11. Light maintenance shops, office and computer equipment
rooms, kitchens, and laundries (for moderately fair
listening conditions)
A-weighted Sound Level (dB)
21 to 30
21 to 30
Not to exceed 30
Not to exceed 34
Not to exceed 42
34 to 47
38 to 47
38 to 47
42 to 52
47 to 56
52 to 61
C-6
-------
Table C-2 (Cont.)
Type of space (and acoustical requirements) Appropriate LA, dBA
12. Shops, garages, power-plant control rooms, etc. (for 56 to 66
just acceptable speech and telephone communication).
Levels above PNC-60 are not recommended for any
office or communication situation
13. For work spaces where speech or telephone commimi- 66 to 80
cation is not required, but where there must be no
risk of hearing damage
EFFECT OF NON STEADY NOISE
The data in Figure C-l are based on tests involving steady, continuous noise,
for which case the noise level is equal to the average sound level. It might be ques-
tioned whether these results would apply to fluctuating noises. For example, when
intermittent noise intrusions, such as those from aircraft flyovers, are superimposed
on a steady noise background, the average sound level is greater than the level of the
background alone. If the sound levels of Figure C-l (and of Table C-2) are
interpreted as average sound levels, it could be argued that these values should be
slightly increased (by an amount depending on the statistics of the noise), because
most of the time that is, except during the flyovers the interfering noise
level is actually lower than the average sound level.
The amount of this difference has been calculated for the two cases of urban
noise and aircraft noise statistics shown in Figure C-2. The data in this figure
(previously reported in Ref. 19) include a wide range of urban sites with different
noise exposures, and an example of aircraft noise at a site near a major airport. In
each case the speech intelligibility was calculated from the standard sentence intel-
ligibility curve (ref. 50) for various values of the average sound level, first with
steady noise and then with the two specific fluctuating noises of Figure C-2. The
calculation consisted of determining the incremental contribution to sentence
C-7
-------
intelligibility for each level (at approximately 2 dB increments) and its associated
percentage of time of occurrence, and summing the incremental contributions to obtain
the total value of intelligibility in each case.
The results, shown in Table C-3, demonstrate that, for 95 percent sentence
intelligibility, normal voice effort and 2 meter separation between talker and listener,
the value of the average sound level associated with continuous noise is less than the
value for an environmental noise whose magnitude varies with time. It is concluded
that for a fixed value of the average sound level minimum intelligibility is associated
with continuous noise. Almost all time-varying environmental noises with the same
average sound level would lead to better intelligibility. Alternatively, for a fixed
value for the average sound level, the percentage of interference with speech (defined
as 100 minus the percentage sentence intelligibility) is greater for steady noise than
for almost all environmental noise whose magnitude varies with time. The relation-
ship between L, and the maximum percentage sentence interference (i. e., for steady,
continuous noise) is given in Figure C-3.
Table C-3
MAXIMUM PERMISSIBLE AVERAGE SOUND LEVELS THAT PERMIT 95 PERCENT
SENTENCE INTELLIGIBILITY AT A DISTANCE OF 2 METERS, USING NORMAL
VOICE EFFORT
L in decibels
Noise Type eq
Steady 60
Urban Community Noise 60 +
Aircraft Noise 65
An extreme example of an intermittent noise, is a noise, of constant maximum
magnitude, that is suddenly switched on and off periodically, in such a way that it is
the only significant contributor to the average sound level (that is, the background
noise during the off-cycle is negligible); during the off-cycle. The background noise
is chosen to be sufficiently low in value such that the intelligibility is 100 percent.
Real-life environmental noises lie between this extreme example and the case of
steady continuous noise.
C-8
-------
0)
_Q
'o
-------
Table C-4 shows how the percentage interference with sentence intelligibility
varies as a function of the level and on-time for a cycled steady noise whose level and
duration are adjusted always to yield a fixed value for the average sound level. Two
situations are envisaged: indoors, relaxed conversation, L = 45 dB, leading to
100 percent sentence intelligibility in the steady continuous noise; and outdoors, normal
voice effort at 2 meters separation, L =60 dB, leading to 95 percent sentence intelli-
gibility in the steady continuous noise.
The combination of level in the first column and duration in the second column
are such as to maintain constant L for each situation, 45 dB indoors and 60 dB
eq
outdoors. The third column gives the percent interference with sentence intelligibility
that would apply if the intruding noise were steady and continuous with the level indi-
cated in column 1. The fourth column gives the percent interference for the cycled
noise in each case.
The results for this extreme example of an intermittent intruding noise indicate
that no matter how extreme the noise fluctuation for the indoor case, there is negli-
gible speech interference for L = 45 dB when speech interference is evaluated as a
percentage of time. However, whenever the intruding noise exceeds 70 dB, all speech
is interrupted until the end of the "on" cycle. Such an interruption is generally
regarded as highly annoying. It is generally a greater problem when listening to
radio or TV when there is no possibility of varying the speech level as can be accom-
plished in a conversation.
It is concluded that the use of average sound level as a measure is conservative
when applied to non-steady environmental noises, when the noises are properly
evaluated on the percentage of total time in which speech interference occurs. How-
ever, if the maximum values of the non-steady noise are sufficiently higher than the
average value, complete interruption in speech communication can occur for small
percentages of the time. When the environmental noise causes this result, the per-
cent of time that communication is interrupted is probably a poor measure of the total
effect, rather the effect is better measured in terms of the annoyance caused by the
interruption. Consequently, it is concluded that the speech interference criteria with
the average sound level measure are best applied to environmental noises which are
steady or non-steady with maximum levels which do not constitute a complete interrup-
tion. Both steady noise and non-steady urban traffic noise are in this category. How-
ever, when the maximum levels are sufficient to cause complete interruption of speech
C-10
-------
Table C-4
PERCENTAGE INTERFERENCE WITH SENTENCE INTELLIGIBILITY IN THE
PRESENCE OF A STEADY INTRUDING NOISE CYCLED ON AND OFF
PERIODICALLY IN SUCH A WAY AS TO MAINTAIN
CONSTANT AVERAGE SOUND LEVEL, AS A FUNCTION OF THE
MAXIMUM NOISE LEVEL AND DURATION
(Assumes 1009o intelligibility during the off-cycle)
Situation
INDOORS, re-
laxed, con-
versation,
L = 45 dB,
eq
100% intelli-
gibility if
noise were
continuous
OUTDOORS,
normal voice
at 2 meters,
L =60 dB,
eq
95% intelli-
gibility if
noise were
continuous
A-weighted sound level
of intruding noise
during on-cycle,
decibels
45
50
55
60
65
70
75
80
60
65
70
75
80
Noise dur-
ation, as
percent of
cycle
100
32
10
3
I
0.3
0.1
0.03
100
32
10
3
Percent in-
terference
if noise were
continuous
0
0.5
1
2
6
40
100
100
5
7.7
53
100
100
Percent in-
terference
in cycled
noise _
0
0.16
0.10
0.06
0.06
0. 12
0. 10
0.03
5.0
2.5
5.3
3.0
1.0
communication, such as often occurs with aircraft noises, annoyance criteria are
more applicable in assessing the effect on humans than are speech criteria stated
in terms of percent of interference.
C-ll
-------
U-t
u
z
LU
U.
£ 60 -
U
z
LU
Z
LU
l/>
LLJ
<
Z
LLJ
U
Q£
40 -
20 -
0
50
OUTDOORS
(NORMAL
VOICE
LEVEL AND
2 METERS
SEPARATION)
INDOORS
55 60 65 70 75 80
OUTDOOR DAY-NIGHT AVERAGE SOUND LEVEL, L , , IN DECIBELS
an
Figure C-3. Maximum Percentage Interference with Sentences as a Function
of the Day-Night Average Noise Level. (Percentage Inter-
ference Equals 100 Minus Percentage Intelligibility, and L,
is Based on L, + 3)
C-12
-------
APPENDIX D
RELATIONSHIPS BETWEEN ANNOYANCE AND AVERAGE NOISE LEVEL
FIRST LONDON-HEATHROW SURVEY
The first survey of about 2,000 residents in the vicinity of Heathrow airport was
conducted in 1961 and reported in 1963 (Ref. 14). The survey was conducted to ob-
tain responses of residents exposed to a wide range of aircraft flyover noise. A num-
ber of different questions were used in the interviews to derive measures of degrees
of annoyance reported. Two results of this survey are considered here. The noise
exposure levels reported in the survey have been converted to approximate values of
Ldn
A general scale aggregating all responses on a category scale of annoyance
ranging from "not at all" to "very much annoying" is plotted as a function of L , in
an
Figure D-l*. This figure presents a relationship between word descriptors and
average noise level.
Among the respondents in every noise level category, a certain percentage were
classified in the "highly annoyed" category. The percentage of each group is plotted
as a function of L , on Figure D-2.
dn
Comparison of the data on the two figures reveals that, while the average over
the population would fit a word classification of "little" annoyed at an L , value of
approximately 60 dB, more than 20% of the population would still be "highly annoyed"
at this value.
*In Figures D-l through 5 of the line indicated is the linear regression computed
from the Pearson product moment correlation. The numerical value of the cor-
relation coefficient, r, is given, as is the standard error of estimates, s ,
D-l
-------
COMBINED RESULTS OF SECOND LONDON SURVEY AND TRACOR SURVEYS
In 1967, a second survey was taken around Heathrow airport in the same general
area as the first (Ref. 15). The results, while attempting refinement over the first
survey, were generally me same. In 1971, the results of an intensive three year
program, studying eight air carrier airports in the United States under NASA spon-
sorship, were reported by Tracor (Ref. 16). Since each of these efforts is discussed
in detail in the references, only an analysis of their combined results is considered
here. Borsky used the data from these studies to correlate annoyance with noise ex-
posure level for people having different attitudinal characteristics and different
degrees of annoyance (Ref. 18).
Utilizing his data for "moderate" responses to the attitudes of "fear" and "mis-
feasance, " the relationship between percent "highly annoyed" and noise exposure level
is plotted on Figure D-3. Again, noise levels have been converted approximate to
L values. It is worth noting that more than 7500 respondents are included in the
data sets from which the computations were derived.
The comparison between the results shown on Figure D-2 and D-3 is
striking in the near identity of the two regression linesindistinguishable at any rea-
sonable level of statistical confidence.
The importance of these two sets of data lies in the stability of the results even
though the data were acquired 6 to 9 years apart, at nine different airports in two
different countries.
JUDGMENT OF NOISINESS AT URBAN RESIDENTIAL SITES
In 1972, a study of urban noise was conducted primarily to evaluate motor vehi-
cle noise for the Automobile Manufacturers Association (Ref. 51). As part of this
survey, 20 different urban-suburban residential locations not in the vicinity of air-
ports , were studied in Boston, Detroit, and Los Angeles. Noise measurements
were acquired and a social survey of 1200 respondents was conducted. Part of the
D-2
-------
survey was directed towards obtaining the respondents' judgement, on a category
scale, of the exterior noisiness at their places of residence.
The average judged noisiness values per site are plotted on Figure D-4 as a
function of measured L, values. The significance of these "non-aircraft" data is
the comparison they permit with other survey data acquired exclusively around
airports.
Intercomparison of these data with the previous data indicate that for an L,
dn
value of GO dB, the site would be judged "quite" noisy, the average annoyance over a
group would be classed as "little, " but about 25% of the people would still
claim to be "highly annoyed. "
COMMUNITY REACTION
Fifty-five cases of community reaction to noise were anatyzed in the Community
Noise section of the EPA report to Congress (Ref. 1, 19). These data comprise a
variety of types of noise sources:
Aircraft 12 cases
Other Transportation 7 cases
Other intermittent operations 5 cases
Steady-state neighborhood 7 cases
Steady-state industrial noise 24 cases
Approximately one-half the cases were associated with daytime operations only
and one-half with 24-hour operations. They contain a wide range of dynamic charac-
teristics, including both infrequent, high level short duration noises and steady-
state continuous noises.
The data for the 55 cases were re-analyzed in terms of the day-night average
sound level. Further, the individual cases can be grouped into three categories of
community reaction, "none, " "complaints or threats of legal action," and "vigorous
D-3
-------
community reaction", as evidenced by organized group activity or legal action. A
relationship between the day-night average sound level and the corresponding com-
munity reaction can be represented by the arithmetic average of the noise levels for
the cases in each reaction category. This result is:
Day-Night Average
Community Reaction Sound Lev el-decibels
None 55
Complaints and Threats of
Legal Action 62
Vigorous Action 72
The functional relationship between reaction category and noise level must have a
curvilinear relationship, since the community reaction is unbounded at the lower and
upper extremes of noise level. That is, the range of "no reaction" obviously extends
to all noise levels below a specified value, and similarly, the range of "vigorous"
reaction is unbounded at very high noise levels. (This accounts for the short scale of
community reaction on Figure 3.
D-4
-------
01
LU
U
Z
O
z
Z VERY
< MUCH 4
0
UJ
LU
g MODERATE 3
LU
Q
z
O
z LITTLE 2
O
Z
O NOT AT
LU ALL '
O
LU
<
1 1 I 1 i I
j^^
^--~ "~~^
^^p^*^^
^^ -**^
^^^^^^
^^^ -^"^
^
^^
^f^^'^
^^ ~^^
^^~^ r = 0.985
_^r^ V =0-u%
I I 1 I I i
45 50 55 60 65 70 75 80
Approximate Day-Night Average Level, L
dn
- dB
Figure D-l. Average Degree of Annoyance as a Function of the Approximate Day-Night Average Noise
Level-Results of First London Heathrow Survey
-------
80
60
T>
to
>*
o
I
-vP
40
20
45
I
I
r = 0.972
=4.4%
I
50 55 60 65 70
Approximate Day-Night Average Level, Ldn - dB
75
80
Figure D-2. Percentage Highly Annoyed as Function of Approximate Day-Night Average Noise Level-
Results of First London Heathrow Survey
-------
O
-3
80
60
40
.c
CD
20
55
i r
r = 0.972
s =4.1%
yx
j i i
60
65 70
75
80 85
Approximate Day-Night Average Level, L , - dB
Figure D-3. Combined Results - British and U.S. Surveys (After Borsky, Ref. 18)
-------
VERY ,.
NOISY D
4
*
C
1 3
0 §>
00 3
I
trt
i
5 2
NOT
AT 1
ALL 4
1 1 1 I 1 .
r"*
* *<^*
^^**+ ~^^
^^. *
r = 0.769 ~
s = 0.15
yx
1 III
5 50 55 60 65 70 7
Measured Day-Night Average Noise Level, L , - dB
Figure D-4. Judged Noisiness at Automobile Manufacturers Association Survey Sites
-------
APPENDIX E
SPECIFIC RECOMMENDATIONS FOR PREDICTING L,
FOR AIRCRAFT/AIRPORT OPERATIONS
The following specific recommendations should be incorporated into the updating
of procedures to predict the Average A-Weighted sound level from aircraft opera-
tions (Ref. 4).
1. The air absorption data contained in the latest revision of SAE ARP 866 (Ref. 9)
are to be used in noise calculations until an updated standard on this subject is
available.
2. The method for predicting ground propagation losses now being used in NEF
calculations, and the algorithm now in use by FAA for transition between ground
and air attenuation are to be employed in predicting noise from aircraft operations.
3. The data acquired for use in the aircraft noise model should allow incorporation
of aircraft acceleration effects in the sound level contours.
4. Data on the effect of density/altitude on aircraft performance and noise effects
should be included for various aircraft operating weights.
5. The acoustical standard day (15°C, 70 percent relative humidity) is to be used
as the basis for noise contours, unless an examination of the mean monthly
temperatures and relative humidities show three months during the year in
which the product of temperature, in C, and relative humidity, in percent, is
less than 400. In such cases, the noise exposure calculations for the airport/
airbase should utilize sound level versus distance curves based on the appro-
priate weather conditions.
6. Computations of the number of average daily operations should correspond to
a "busy-day" if differences over weekly or monthly intervals occur.
7. Allowance for flight path dispersion should be included, based on a suitable
model derived from flight path observation data.
E-l
-------
Aircraft ground runup operations for maintenance purposes should be included
in the noise calculations. Noise produced while the aircraft is on the runway
and associated directly with takeoff operations should be included in the take-
off noise calculations, and thrust-reverser noise should be accounted for in
landings.
E-2
-------
APPENDIX F
MINUTES OF TASK GROUP 3 MEETINGS AND LIST OF ORGANIZATIONS
AND INDIVIDUALS PARTICIPATING IN TASK GROUP 3 ACTIVITIES
Fl. 1 Minutes of Meeting Number 1, 15 February 1973.
F1.2 Minutes of Meeting Number 2, 27 February 1973.
F1.3 Minutes of Meeting Number 3, 10 March 1973.
F1.4 Minutes of Meeting Number 4, 4 April 1973.
Fl. 5 Minutes of Meeting Number 5, 11 May 1973.
F-l
-------
ATTENDANCE
TG3/(1eetings
NAME.
Betsy Amin-Arsala
Peter P. Back
'.Jil lifliii 6. Becker
Lawrence P. IJedore
Robert S. ijcnnin
'.'Iodine ;; Ian en a re
R. 'll. Coykendall
Jonn Curry
Diane Jon ley
LCDR Leigh E. Doptis
Ken Eldred
Stephen A. Falk
Earl Fish
Jack Fredrickson
'J. J. Galloway
H. von Cierke
Harvey iiubbard
Raelyn Janssen
Daniel L. Johnson
John ('j. Kruk
L'avid L-je
3ort J. Lockwood
A. L. .".cPike
J. filler
Clifton :'!oore
Robert ,'orso
Sidney J. '1?fiery
liarve.y J. -.'ozick
Shellio Ostroff
'Joel A. Peart
Artnur Rubin
Harvey B. Safeer
Robert ;J. Simoson
:i. C. Stoele
Jack Suddroth
Alice Suter
'Jrian Tsnnant
J. ". Thoi'ioson
John !i. Tyler
'.'. Dixon ;.'ard
John K. ..'atsrs
Sir.ioiiC Ysniv
!;,cbert '..'. Youno
MJGS_ ATT.EJlp.ED
2, 4,5
2.3,4,5
1,2.3,4,5
5
2,3,4,5
1
3^4,5
2
1, 3
1,2,3.4,5
1,2,3,4,5
TO /I
I ,<. , u%d
BBN
JIH
Douqlas Aircraft
(| Conoanv
EPA (Chairman USAF)
'I ASA --Lang ley
Envi rcninental Defense Fund
EPA (USAF)
Pioer Aircraft Ccrooration
QSiiA - OOL
Los Ancjles Dont. of Airports
Coinjlas Aircraft
H'Ji
Los Anqoles Dept. of Airports
Pratt and '.Jhitnpy Aircraft
:PA (;.iS."F)
Ef'A (Consulta-it)
Infcrn:atics
.,'ational bureau of Standards
5'OT
r-;iT
I'PA
ceinc Ccr;,patv
Lockloed Com any
".' . 0 . 1 . S . E .
EPA (Consultant)
Environmental Defense Fund
r n n / r> ' A r-
uTM/ Al.lL
;avol ;Jnd:?rsoa Center
F-2
-------
LIST OF THE ORGANIZATIONS OF THE MEMBERS
THAT ATTENDED TS3/MEETINGS
ORGANIZATION
MEETINGS ATTENDED
r E P A
a nts
EPA
City of New York
Dept. of Navy
Bolt, Beranek and Newman
U. S. Dept. of Housina 8 Urqan Development
Dept. of Labor
Informatics
National Institute of Health
NASA
.National Bureau of Standards
Dept. of Trans porati on
U. S. Air Force
In dust Hal
Piper Aircraft Company
Garrett-Ai rResearch
Air Transport Association
Pratt & Whitney Aircraft
Douglas Aircraft
National Business Aircraft Asscc.
Los Angeles Dept. of Airports
Seeing Company
Lockheed Company
United Airlines
Other
Council of Environmental Quality
George Washington University
Massachusetts Institute of Technology
Environmental Defense Fund
N.O.I.S.E.
1,2,3,4,5
2,3,4,5
1,2,3,4,5
1,2,3,4,6
1, 5
3,4,5
1, 3,4,5
3,4
1,2, 4,5
1, 3
5
1,2,3,4,5
3, 5
3,4,5
1,2,3,4,5
1,2, 5
1,2,3,4,5
5
2,3,4,3
1,2,3,4,5
4
2,3,4,5
1, 3
2, 4,5
3,4
2,3,4
2,3,4
F-3
-------
Fl. 1
SUtJjrCT:
DEPARTMENT OF THE AIR FORCE
657OTH AEROSPACE MCDICAL RrSf:Af?CH LABOrtVTORY (AFSCi
WmGHT-PATTF.Kr-OM AIR FORCE EASE. OHIO 45433
AMRL/13B 16 February 1973
TO. Participants in Activities of Task Group 3
Impact Characterization of
Aircraft/Airport Noise Study Task Force
1. Summary of first mcctin;: on 15 Fcb 73
a. The task ^roiin disc':-':-ed implications of and approach to ovcrr.il
assignment on the basis of the attached subtasks . After consider:;::; ti;o
constraints imposed by the Noise Control Act the tentative conclusion
was that the Noise Exposure Characterization and assessment method would
have to be a weighted overall sound pressure level measure similar to
the CNHL procedure. The chairman mentioned that a CllABA working grcup is
working on such a procedure in connection with general Noise linviron-
mental Impact Statements and that more information on this ir.cthoJ vcuic
be available at the next meeting, '['lie approach to recommend inc. permis-
sible limits was discussed; it was considered desirable to present all
information in terms of percentage of people affected with respect to
neaitn (^annoyance.) , etc., ana leave rinai decision open for nfi'm m slr:-r '. vc
economic decision. It was decided that study of the economic ir.pact of
selecting specific permissible levels could not be an isolated task ;;ro,.;-.
3 exercise but would have to be a joint task group 2, 3 and 4 exercise-
after these groups have completed their primary assignments . The steer-
ing covmittee will be made aware of this to prepare fox this, probably
through an additional economic consultant capability.
b. The task group discussed the following weighting factors for the
noise exposure characterization:
1. frequency weighting: A-weir.hting appears the only possible
solution for the ;,;:.. '.out, but ;.ost participants i\,vored the PO.V.-;J bill ;/
to go to N- (D-)wcighting as soon as such a network is standardized and
widely available.
2. tone correction - probably no
3. period of day - probably 2 periods
4. background noise - probably not to be included.
5. seasonal correction (ICAO)
2. All participants were asked to study the problems and to submit thi. i;-
position prior to or at the latest at the next meeting. I know it Js
F-4
-------
impossible for all of us to get an official position of the organiza-
tions KG represent in such time periods. In spite of this it uould
help if you would submit your comments in two parts:
a. What do you think the official position of your organization
will be on this matter. ('Iliis will help us to fori::iil atu our justifi-
cations. )
b. What is your personal technical recommendation regarding this
subject.
Please be prepared to discuss and help ivith the actiinl i.'orh on the
preparation of the task group subarcas outlined on tho rLt:ic':;cd.
Please feel free to propose changes to the outli;;'. attached.
3. Our next meeting will he on Tuesday, 27 i-'cb 73 at 0:30 a.m. at LPA,
Washington, DC. My phone numbers arc: office (5!3) 255-3602, home
(513) 767-2181.
#{
I1ENNING C. VON G1E15KI; "' < Atch
Director Out!inc
Biodvnamics f. Bionics Division
*i!eetiag location will be 1111 20'oh Street, )J.W.
5th floor, Iloo;n 531
Mailing address for EPA/GNAC rciiiains uncli;ui~c
-------
TASV. Gsnr' 3
IMPACT CHARACTER! '.T'.OTi
SELECTION OF NOISE EXPOSURE CHARACTER !ZA 7 iOfi A?3 ASS
METHOD
o EVALUATION OF EXISTING AO iOO.-OSID ;.:1T:;ODS
WITH RESPECT TO TECHNICAL t:ZSIT, SCO.'iC^Y AN
ENFORCEMENT THROUGH MONITORS KG
o DETAILED DESCRIPTION OF SELECTED KETKCD
INCLUDING DECISION ON ALL PARA;-.ZT£RS 70
GUARANTEE UNIFORM AND ECONOMIC APPLICA-
TION
o RELATION OF SELECTED KETHCD TO riOlSZ ;:.... JT
CHARACTERISTICS ISED FOH OTiiZK ?L.,?GCZS
(AIRCRAFT NOISE CERTIFICATION, HiGl^AY :,0.3
LAND USE PLANNING, ETC.)
o PROCEDURE AND ECONOMY OF ^G;JiTO^ir;G ;:O.CI
EXPOSURE
SPECIFICATION OF MAXIKl^ PZ[^tSSSCL£ MiSl LX?CCL::i
cS
DESIRABLE NOISE EXPOS^'Z LZVc
RESPECT TO PU3LIC KEALTii A,:i) UIL
ESTIMATION OF CCO^IC iC4?;,CT OF
PERMISSIBLE LEVELS
RECOMMENDATION OF ttAXIi^ PZ^SSSI2L£ LIVZLS
AND IMPLEMENTATION
MONITORING OF
F-6
-------
Fl. 2
ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
TASK GROUP 3
MINUTES OF SECOMD MEETING, 27 Feb 73
I. The cnairraan opened the meeting at 9:<40 and welcomed the task group mem-
bers, who had participated in the first meeting, and new participants. (Sec
attached list.) He briefly reviewed the events o£ the first organizational
meeting of the whole task force and of the first meeting of Task Group 3. The
minutes of the first meeting, copies of the Noise Control Act 1972, assign-
ments to the task force and time schedules discussed at the first meeting were
distributed and discussed. The chairman asked all members to submit by the
end of each meeting drafts of specific items they brought up at the meeting
and want to have recorded specifically in the minutes. He also asked that
members submit between meetings (a) technical papers, documents, position
papers or statements which would support task group activity or are relevant
to decisions reached or activities planned by the group, and (b) more formal
position papers to be included in the final task group report, particularly
if they desire their position to be recorded as being not in full agreement
with the task group decision or course of action.
2. A detailed discussion of the work assigned to the task group and the chair-
man's proposed outline of task group activity and potential outline for the
report followed. The chairman stressed that this outline is tentative and
subject to change. A letter written by four Environmental Groups (N.O.I.S.E.,
E.D.F., E.A., A.C.A.P.) addressed to Mr. Schettino was introduced and distrib-
uted. Mr. Tyler expressed the concern of these groups in more detail and
submitted another letter specifically addressed to task group 3. The main
concerns of these letters were: 1. The task force study should deal not only
with the adequacy of existing FAA measures and regulations with respect to
noise but also should review the whole past history of FAA's dealing with
the aircraft noise problem. 2. All reports, papers, government documents,
etc., dealing with previous committees, actions, studies, regulatory histories,
etc., concerned with the same issues should be made public and should be at the
disposal of the task force. The chairman and most members of the group dis-
agreed with Mr. Tyler and interpreted the Noise Control Act and the assignr.er.t
to the group to review the adequacy of existing regulations, procedures, etc.,
and that nothing would be gained from a review of history. The chairman
assured the concerned groups that all efforts would be made by EPA to have
the relevant documents available at the task force headquarters for use in the
study, that the Informatics noise information retrieval system would be avail-
able for task force use and that he himself and several other members of task
group 3 had participated in most of the previous studies and conferences men
tioned in the letter and that he thought most of the important documents co;.ld
be made available from the personal files of these task group members.
F-7
-------
3. At this time Dr. A. Meyer, Director of ONAC, EPA, joined the group for 45
minutes and restated EPA interpretation of the Noise Control Act and task force
goal. Specifically he confirmed that the charge was to review the adequacy of
existing noise control regulations and actions, etc., with respect to Public
Health and Welfare. He emphasized that FAA never had the charge of taking
action with respect to Public Health and Welfare and that it could not,have
been the intent of Congress to have EPA investigate the history of past FAA
actions. He satisfied all task group questions and concerns regarding this
problem. Dr. Meyer promised to take action with respect to participation of
the following four government agencies, contributions from which are considered
important for expedient, economic and unbiased task group 3 activity: DOT and
FAA, Department of Labor and HEW. (Of the four all but DOL had been invited
to participate. Dr. Meyer discussed the reservations DOT had at this time to
participate in the task force effort and expressed hope that this question
could be resolved soon.)
4. The task group (including Mr. Tyler) agreed on the proposed approach and
report outline without alteration and addition. The chairman stressed the
importance of agreeing on the basic approach since this decision on the measure
for cumulative noise exposure is a prerequisite for efforts by other task groups.
He mentioned another parallel study effort conducted by a National Academy of
Sciences (CHABA) working group at the request of EPA to draft "Guidelines for
Environmental Impact Statements" for all types of noise (not only aircraft
noise). Dr. von Gierke, who is also chairing the CHABA working group, and
Dr. Galloway presented details about the proposed CHABA approach and how the
same approach, as tentatively agreed upon in the first meeting, could be
selected by the task group as the basis for characterizing cumulative noise
exposure. Everybody agreed that it was not only desirable but essential that
any methodology proposed for cumulative noise exposure characterization must
be applicable to all types of noises. The proposed method, selected as basis
for further study, is a weighted noise exposure level (W N E L ) similar to
the CNEL based on the weighted energy time integral of sound level A with a
correction for nighttime exposures.
5. As a continuation of meeting //I, specific details of the proposed W N E L
were discussed on the basis of a rough draft document submitted by Dr. Galloway
and distributed to all participants:
a. Frequency Weighting: Some objection was voiced to using the "A"
weighting instead of the "D" weighting. Mr. Sperry (EPA) stated that he
thought the whole method proposed was a step "30 years backwards" and intended
to write a position paper against using the "A" weighting scale. Mr. Sperry
was assured that selection of a common, relatively simple and practical method
for measuring noise exposure of all noises does not mean that certification of
aircraft and other equipment and type emission standards could not and should
not use more refined methods and noise descriptors such as EPNdB in FAR-36,
It was decided to make this point very clear and explicit in the written
report of the task group. The nonavailability of a standardized D-network
was felt by most members to dictate the use of the "A" scale at this time
although the possibility of proposing a conversion to the "D" scale for a
later date was discussed. However, it was felt by most that even such a step
F-8
-------
would require better data on the advantages of D over A as indicator with
respect to Health and Welfare effects than are presently available. The chairman
pointed out that annoyance is only one aspect of Health and Welfare.
b. Tone Correction: It was suggested that when recommending limits tones
should be assumed present in the noise unless shown by a more sophisticated
method not to be present. There was substantial argument against this idea
and for the present tone correction will be neglected. It was felt that tone
penalties should be in certification and emission requirerients but should not
be included in the WNEL because of the monitoring complications and because of
several technical uncertainties regarding the penalties.
c. Period of Day: There was a consensus that two periods were required
with the period at night to be 9 hours and weighted with a 12 dB (10-15 dB)
correction factor. Mr. W. Becker pointed out the desirability to make the
night period start at a uniform time. The task group will attempt to generate
data to support the amount of the correction factor. (Action - Mr. Eldred).
d. Background Noise: The WNEL method provides no special correction for
background noise; the WNEL measure itself includes automatically the background
noise present. The task group agreed to this approach.
e. Seasonal Correction: The ICAO provision was discussed. This correc-
tion will probably be dropped from consideration. The rationale for omitting
seasonal correction will be drafted by Mr. Tyler.
All task group members were asked to submit relevant data, draft justifications
and/or position papers on the basic WNEL approach and on (a) to (e) above
prior to or at the next meeting. The draft of the methodology document with
supporting appendices will be compiled and further refined by Dr. Galloway.
6. Discussion of specification of maximum permissible noise exposure levels:
The basis for selecting and recommending such levels with respect to public
health and welfare were discussed. The following criteria will be considered
in the decision process: (a) risk of hearing loss, (b) percentage of people
severely annoyed, (c) requirement for speech communication, (d) "normal,"
natural background noise, (e) economic impact of selecting various exposure
levels. l't became clear that setting maximum permissible levels for cumulative
exposures does not make the setting of limits for maximum sound pressure levels
or the limitation of maximum nighttime noise levels superfluous. This must bo
made clear in the report, even if the task group attacks only the problem of
cumulative noise exposure.
In preparation for more detailed committee discussion and decisions on this
subject,background material on (a) to (e) is to be submitted for the next
meeting.
Mr. Back and Mr. Eldred were assigned primary action to prepare such material.
In particular data and graphs on a national basis are desired on: how much
land is in the various noise exposure zones, what is the price of this land
and how many people live in these zoofifi? Rough estimates of these figures
F-9
-------
(not only for airports but for other noise exposure zones such as along high-
ways) would assist to assess the economic iropact of selecting specific permis-
sible levels. The chairman proposed that such estimates should be available
for zones equivalent to NEF 25 to 45.
Mr. Eldred will correlate information and submit approaches to select per-
missible WNELs.
The need for access to DOT contractor material (Wyle) was emphasized and desir-
ability for HEW, DOT and HUD (Mr. Miller) participation in this phase of task
group activity. The chairman will make efforts to obtain support from these
agencies.
7. No specific material to be recorded in the minutes of this meeting were
submitted by task group members.
8. The date for the next task group meeting was set for 20 March 1973,
9:30 AM at 1111 20th Street, NW, Washington DC. The following meeting will be
on 4 April at the same time and place.
JS
EWINC
HENNING E. VON GIERKE 1 Attachment
Chairman, Task Group 3 Attendance List
F-10
-------
F1.3
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
'-«i wo*0" WASHINGTON. D.C. 20460
Task Group 3
Minutes of Third Meeting, 20 March L973
1. The Chairman, Dr. von Gierke, opened the meeting at 9:30 and welcomed 21
members wno participated in the earlier meetings and 8 new members. The
Department of Labor and the National Institute for Environmental Health
Sciences (NIH) were represented for the first time. HUD had been requested by
the Chairman to be present at this meeting; however, !fl)D did not feel that it
was necessary to present an opposing view to the Task Group recommendations
as stated up to the present.
2. A complete record of all reports, minutes, position statements, etc., o£
Task Group 3 is available in a Special File in the office adjoining the con-
ference room (Room 531). Small reports and working papers will be distributed
to each member, but the large documents with background material only will
not be reproduced and/available only in this file. All members are welcome
to use the contents of this file, but the Chairman requested that the material
not be removed from the office except for copying in this office. The large
reports containing background material, as well as other references, will bo
available through Informatics, Inc. Attached is a list of the documents that
are considered a part of Task Group 3's official file. Each document will
have an I.D. number (e.g., TG3/14).
3. The Chairman received several letters on position papers, as well as
replies, back from action items. The letters were distributed to each member
and discussed as follows:
a. Lockwood's Letter (TG3/10)
Mr. Lockwood thought (1) that the method of Weighted Noise Exposure (W.N.t:.)
might be too complicated and (2) that it would be necessary to use a simple
method that could be presented clearly in a law court. In fact he proposed
that the task force's actions should be guided to a larger extent by past
court decisions. Several members answered that with respect to (1) they
thought the proposed W.N.E. would be such a simple method. It could either be
accomplished manually over a 24 hour period with a dB(A) meter or could be
accomplished by a simple dosimeter, probably costing under $1,000, that meas-
ures the total noise energy over the 24 hr period.
After considerable discussion, there seemed to be general agreement that
use of W.N.E. would resolve most of Lockwood's objections to the impractical
and hard to use methodologies of the past. With respect to use of past court
cases, it was suggested that lack of uniform scientific and legislative guid-
ance has produced many of the apparent idiosyncrasies in court judgments. Much
F-ll
-------
of the problem can be resolved by a measurement system, such as the WNE, which is
both simple and scientifically sound. The Aircraft Sound Descriptor System (ASDS)
was brought up and discussed. Prof. Simpson of MIT explained what ASDS normally
includes. He also discussed some of its shortcomings. Mr. Moore stated that ASDS
as used by LA Airport is modified' tq. include actual SPL. Dr. Galloway then pointed
out that with such a modification, .it would be an easy^ matter to-convert the measure-
ments to the single WNE number that is recommended.
b. Ken Eldred gave a progress report for looking at the rationale behind the
12 dB difference between daytime and nighttime exposure. By using 55 noise expo-
sure cases, he believes that he can show that the optimum correction is between
8-12 dB. The final results and conclusions will be distributed prior to the next
Task Group meeting.
At this time Mr. Coykendall brought up the point of separating the night-
time measurements from the daytime measurements and using two separate criteria.
This was discussed in detail and the final consensus reached was that the night
correction factor was a satisfactory approximation. The Chairman pointed out
that having two measurements and criteria, daytime and nighttime, would prevent
establishment of simple single average daily and/or yearly noise values.
c. A set of typical exposures measured in LEQ was distributed to all members.
These had been prepared at the Chairman's request by Dr. Galloway and were a
result of BBN's efforts of measuring actual noise levels in homes and offices.
(Report is numbered TG3/11). These are to be used in further discussion of typi-
cal internally generated WNE's inside homes and in the decision if WNE limits
are better recommended in terms of environmental outside noise levels or levels
inside buildings; i.e., levels at the listeners' ears.
d. Peter Back presented the status of evaluating the economic impact of
protecting the population against variousNEF doses. His results were not complete
at this time. An estimate was given that the NEF 30 contour would enclose 2,000
square miles of land and that to buy such an amount of land would cost approxi-
mately 92 billion dollars. The amount of people inside such a contour for var-
ious noise sources were:
Aircraft Noise 7-1/2 to 16 million
Freeway Noise 2 to 5 million
Arterial Road Noise 7 to 14 million
Construction Noise 10 million
The Chairman requested such information for at least two more NEF values. Mr.
Back said that he would try to have these available in two to three weeks.
e. John Tyler provided a status of his report on seasonal corrections. He
indicated that essentially such corrections are best neglected as there are sev-
eral opposing factors that enter into such a correction. Use of inside-the-house
dose levels as exposure limits would even further reduce the need of such correc-
tions. Tyler will write up the report by the next meeting.
f. Mr. Hubbard, as an action item of the last meeting, presented a paper
on tone correction (TG3/8). His final conclusion was that tone correction was not
necessary.
F-12
-------
4. Other items discussed.
a. Mr. Coykendall pointed out a mathematical error in one of the formulas for
defining W.N.E., page 2 of TQ3/6, Draft text on "Noise Exposure Units." The correct
formula is;
WN1£ = 10
+ 973500$?)! 10 ^ dt
2201
b. Mr. McPike brought up the idea that the effective noise that is measured
inside a typical house is more important than outdoor noise measurements. Currently
aircraft are being designed to reduce outdoor noise. The design of aircraft for
noise reduction is different if indoor noise is to be reduced; as such indoor
noise comes more from the lower frequencies. The group did concur that the use of
the measured or estimated indoor noise would lead in principle to better definition
of the typical human noise exposure. Mr. McPike was asked by the Chairman to pre-
pare a paper on the methodology and rationale of transforming outdoor noise measure-
ments into an expected indoor noise level.
c. David Lee, Dept. of Labor, discussed the possibility that the methods and
recommended limits provided by this Task Group might be in conflict with the juris-
diction of the Labor Department, particularly in the area of potential hearing im-
pairment. The Chairman stated if sucn conflicts occur, resolution would be required
at a higher level than available at this Task Group.
d. Mr. Cook mentioned that in the deeper stages of sleep, low frequencies
were more likely to awake a person than the equally intense A-weiqhted sounds at
higher frequencies.
e. John Tyler pointed out that the economic impact of the NEF contours could
be significantly changed if technological or operational changes reduced the noise
sources and thus reduced the area enclosed by an NEF contour. It was recognised
that predictions based on existing NEF contours will be approximate only and will
change with changing emission level reductions. Mr. Back pointed out that such
improvements in noise sources may not be accomplished unless regulations based
on many of the recommendations of this Task Group establish the need of such
noise emission reductions.
f. The Chairman read various definitions of "Public Health and Welfare" (Clean
Air Act, WHO, EPA) and distributed a copy of the same to each member.
g. Mr. Lockwood took as an action item to provide the Chairman and Mr. Back
data of complaints and court cases versus NEF contours about the LA Airport.
F-13
-------
5. The Chairman specifically asked Mr. Lee (Department of Labor) and Mr. Cook
(NIH) to prepare papers representing the positions of their agencies concerning
the methods proposed by the Task Group.
6. The Chairman emphasized that per .the schedule, th* nex-t meeting is the last
time for technical input. All technical papers should be ready by this 4 April
1973 meeting. The meeting will start at 0930 at the same location (1111 20th
Street, NW, Washington DC).
7. No specific comments to be included in the minutes of this meeting were sub-
mitted by Task Group members.
HENNING E. VON GIERKE
Chairman
F-14
-------
F1.4
Task Group 3
Minutes of Fourth Meeting, A April 1973
1. The chairman, Dr. von Cierke, opened the meeting at 0930 and welcomed
23 neir.bers who had attcr.ccd previous meetings and three new participants
(see attached lists). The chairman mentioned that Dr. Karl Krytcr was
specifically invited by the EPA (ONAC) to attend the meetings in response
to the specific request by N.O.I.S.E. subletted at a previous meeting, buc
was apparently unable to attend. The necting was conducted in two sessions,
both continuing the work planned or tentatively discussed or decided upon at
previous meetings. The morning session considered the selection of a noise
exposure characterization and assessment method while the afternoon session
considered the bases for selecting and potentially recommending maximum
peraiissiblc noise exposure levels.
2. Selection of a ;\'oise Exposure Characterization and Assessment Method.
The chairman asked if there were any new comments on the following factors:
a. Use of A weighting scale. No ncv; comr.-.ents were presented. Mr. Becker
did emphasize in the afternoon that he thought the use of d3A was a f>rcac-
idea. Reg Cook formalized his earlier conplaint in his letter (TG 3/31
discussed later).
b. Equal Energy Rule. The chairman stated that for annoyance, research
has indicated that equal cncrp.y is probably the best approach. The members
were asked, however, if anyone knew of any data that would show that a 4
-------
At this point a lengthy discussion evolved concerning a multitude of
ideas on indoor-outdoor measurement and related exposure specification.
Galloway suggested that the indoor/outdoor situations are not so
different as to be expected from house attenuation values as people will
expect less noise intrusion indoors. McPike stated that lie felt that there
are more complaints front indoor problems. Siuone Yaniv argued that the most
sensitive groups, such as children and the aged, should be protected. Several
members expressed the fear that focusing on the indoor noise exposure would
entirely neglect the outdoor exposure.
John Tyler added that outside exposure is important. Apartment
houses without yards can generally accept wore noise than the residential
single family dwelling. He suggested that one standard noise exposure or
noise energy dose be allowed per individual. Each community could decide
how to keep noise exposure under this limit. Thus, zoning laws and building
codes might be different in each community as based on different living styles
such as indoor/outdoor ratios. Tyler also presented the SAE report (TG 3/27)
on House Noise Reduction Measurements.
Dr. Yaniv asked who was going to determine what indoor/outdoor ratios
to use. This question was left open ac the time of the meeting.
The chairman summarized that the noise exposure chosen to be used in
the task group report will be based on the environmental exposure of people,
i.e. , that hunan exposure will be based on our estimate of his exposures to
indoor and outdoor levels, which will be added to result in the total average
daily noise exposure.
e. Nighttime Correction. Ken Eldred gave & rough draft of noise exposure
measurements of 63 sites. He thought that a nighttime correction of 10 d3
would be best. In most locations, 10 dB additions give approximately an equal
distribution for 24 hours. If too high of a nighttime correction is used,
then nighttime noise completely controls the exposure measure. He will prepare
a final working paper on this subject incorporating results of the discussion.
3. Consideration/specification of Maximum Permissible Noise Exposure Levels.
The following items were discussed by Che cask group.
a. NEF contours. Mr. Lockwood discussed his 27 March letter (TG 3/28)
concerning the noise complaint history at the Las Angeles Airport. A nap
of the L.A. area was presented. Depicted on the map were various court cases
and complaint areas. The KEF curves were also drawn on the map. Mr. Lockwood
noted that there were «ore complaints in the summer than in the winter (200-300
complaints/month versus 40-50 complaints/month) and he guessed that only 2-3"
of the complaints were outside the NEF-40 contour. The chairman noted that
he thought the group should be guided by what is known about huiaan effects,
not just court cases. Bill Galloway stressed that there is a difference;
between complaint level and acceptability level. Lockwood replied that the
courts will correct the results if the regulations are not good. The chairman
requested that if some of the group members felt that NEF or a similar systca
as presently considered by the task group is not good, then what system can be
used? In response, Mr. Seeker asked if it was too late to submit a paper
F-16
-------
about the changes that would nake NEF a better measure. The chairman said it
would not be too late to submit such a paper and encouraged Mr. Becker to do so.
b. A paper (TC 3/29) "Hearing Loss Expected For Various Noise Exposure
Values" was presented by Daniel L. Johnson. The conclusion reached was that
for practical or typical environmental noise situations, a noticeable hearing
change (90 percent of the population will have less than a 10 dD Noise
Induced Permanent Threshold Shift at the most sensitive 4000 Hz frequency)
will not occur for a Lcq as treasured outside that is below 85 dDA.
c. A paper (TG 3/30) "Percent of the Time that Speech Iriterfare-ace will
Occur for Various Leq Values" was presented by Daniel Johnson. Ken Eldred
su£f.ectcd further that it would be helpful to deterr.ane ho-.; sensitive the
calculated percentages were to the particular noise profile assumed. Johnson
said that he would attempt to s'aow ho*: rauch the percentages change by
assuming various other noise patterns. A limit for i!E as required for Speech
Interference was not reconnendcd at this time.
d. Letter (TG 3-31) fror.i Reginald Cook (NIH) was discussed. Dr. Falk
(NIH) thought that noise would cause other physiological changes and
suggested that future research in this area be recormendcd by TG3. Dr. von
Gierke stated that he thought that it was not the primary purpose of the
Task Group 3 to request future research but to make the best rccornendations
for practical use based on available data.
e. Letter (TC 3-32) from Dept of Labor was discussed next. Dave Lee of
the Dept of Labor discussed the paner. lie emphasized that what the Task
Group 3 suggests must be enforceable. He then asked if Task Group 3 was at
a point that it could write a standard? He thought that for the most part,
firm conclusions were not coning out of the meetings. The chairman replied
that perhaps time was too short to resolve all the problems, but many questions
(such as use of A weighting) have been resolved. The outline (see TG 3/2)
was reviewed at this point in response to several questions concerning where
the task group was headed. In essence, the chairman will now coordinate the
writing of a preliminary draft that will draw upon the iter.is discussed in
the previous meetings. Finn decisions will be made In this draft and
presented for review to the Task Group members prior 'to the next meeting.
f. Letter (TG 3-33) from the Boeing Company was distributed and
discussed.
4. No specific comments to be included in the minutes of this meeting were
presented.
5. The chairv.ian stated that the next task was to prepare a draft of the
document required fron Task Group 3. The next meeting was tentatively
scheduled for 11 May 1973, 9:30 at 1111 20th Street, NW, Washington, D.C.,
but would depend on finishing the draft on tirac for review. Each rr.einbcr
will receive confirmation of the date for the next meeting. I_f due to
possible mail delays ncnbers do not have confirmation of the 11 May meeting
jJatc fit the time they musf~maicc~travc'r"pTansl rucy~sHouT3"e'lie'c^r~\7It~ir tl'A-u.s'AC
or Dr. von Cicrke by phone it^tlTiJ~r.iectTrij^t'aTtcs~place~a's~s'c'TTe3'ur
-------
F1.5
ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
TASK GROUP 3
Minutes of Fifth Meeting, 11 May 1973
1. The chairman, Dr. von Gierke, opened thfc meeting at 0930 ar.a v/elcorr.ec two
new members, Harvey Safeer of the Department of Transportation and Lav/rence
Bedore of the National Business Aircraft Association. Twenty four (2'r) rr.er..-
bers who had participated in earlier meeting^ were also present (see attached
attendance list).
2. The draft report of Task Group 3 was completed and mailed to ail
by 5 May 73. The meeting was devoted entirely to review of 'his draft report.
The review' consisted of two parts: (1) the questioning of each r.enber present
if the member had any major or significant criticism of th. -. ei.ort and (2)
recommended editorial changes.
a. Major Criticisms: The entire morning and part o2 --.& .- ...or. were
used to discuss specific criticisms of the report. Individ;.-. _ :..j..:s are
best described in the individual position papers on comments ~ -~.-.c by
Task Group 3 members (see list of Key Documents). However, a c... , ;u~~ary
of the overall comments is as follows:
(1) All Task Group members present supported ~.ie intent -._ -.r.eral
goal of the written draft.
(2) Several members expressed that the specif-. :naximutr. r.c
recommended (L, = 80 dB for immediate implementation «..;.-' ',.^ = 60 c.. -JG .:
long range goal" were too low or the basir. r'oi* recommenc... ; rruch lev> .. ;.
adequately described. This was especially 'rue of tht gcai of L . = v.O c.
The chairman pointed out, in the final analysis, any liir.it is basical:v a
value judgment that the EPA will be required to r.itke. It was noted t..ar
time schedule for implementation of the 60 dB level was not suggested
a time schedule would depend on factors such as the economic impact,
sidered in the draft report.
(3) The possibility of adding or expanding a > ..of sections ir.
the report was discussed. Time permitting, it was gent. _..y agreed by The
task group that the following items would be incorporated into the report or
Task Group 3:
(a) A discussion of how the other task groups should cv : ;uld
use L, as a measure.
dn
(b) A discussion of how L^ could be used as a reguic.,. measure.
(c) A more detailed discussion of how L, relates to noi: .
measures used in the past.
F-18
-------
b. Editorial Comments: Detailed editorial comments were presented by
many of the task group members and will be considered in the final craft
report.
3. Any comments that concern the writing of the final task group report
should be submitted by 21 May. Official comments for the Annex should be
mailed by 24 May. Please address all comments in duplicate to Dr. von Gi-.. .
Chairman, Task Group 3. The EPA address should be used for the original and
the following address should be used for the copy:
Dr. H. von Gierke
Chairman, TG #3
6570 AMRL/B3
Wright-Patterson AFB OH 45433
The next meeting will be a general meeting of all task groups and is
scheduled for 14 June 1973. The exact location in Washington DC will be
announced later.
Daniel L. Jphnson
F-19
-------
APPENDIX G
POSITION PAPERS AND MATERIAL SUBMITTED BY
TASK GROUP 3 MEMBERS OR OUTSIDE ORGANIZATIONS
Letter from Environmental Defense Fund et al., dated 23 February 1973.
Memo from John Tyler (N.O.LS.E.) "Comments on Proposed Scope of Activity of
Task Group 3, " dated 27 February 1973.
Letter from H. Hubbard (NASA), dated March 12, 1973, on pure tone considerations
in measured community noise.
Letter from Bert J. Lockwood (Los Angeles Department of Airports), dated March 2,
1973, concerning Task Group 3 efforts on impact characterization.
Letter from William J. Galloway, dated March 9, 1973, transmitting 24-hour samples
of indoor and outdoor noise exposures.
Memo from N.O. I.S.E. "Seasonal Changes" dated 4 April 1973.
"Determination of Indoor Sound Levels for Jet Transport Aircraft1' prepared for Task
Group #3 by Douglas Aircraft Co., dated 29 March 1973.
Letter from Bert Lockwood of March 27, 1973 concerning Noise Complaint History
of Los Angeles Airport.
Letter from Richard H. Broun (Acting Director, Environmental and Land Use Planning
Division, HUD), dated March 13, 1973, expressing HUD's position on development of
a single noise measurement index, attaching HUD letters to FAA and AOCI.
Letter from Reginald Cook dated 3 April 1973 concerning NIH comments to Task Group
#3 Impact Characterization Study.
Letter from Department of Labor dated 4 April 1973 concerning TG3 Aircraft/Airport
Noise Study.
Letter from Boeing Company dated 2 April 1973 concerning various Boeing comments
on EPA's Task Group #3 objective.
Letter (dated 13 April 1973) from James F. Miller, Director of Environmental and
Land Use Planning Division, HUD, concerning reports presented at the 4 April 1973
Task Group 3 Meeting.
Letter dated 26 March 73 from Merle Mergell, Mayor of City of Inglewood, to John
Schetttno, EPA (ONAC) concerning recommendations to the Aircraft/Airport Noise
Study Task Force.
Letter from Gordon L. Getllne, Chairman, Subcommittee on Helicopter and V/STOL
Noise, SAE Committee A-21 dated 3 April 73 concerning Selection of Noise Exposure
Characterization and Assessment Method.
G-l
-------
Memorandum from Robert W. Young to Task Group 3 chairman, dated 9 May 1973.
Subject is Material for Report on Aircraft/Airport Noise.
Letter from Daniel L. Johnson, 10 July 1973, on an alternate method for considering
the effect of average sound level on speech communication.
G-2
-------
ENVIRONMENTAL
DEFENSE pp. 1?12
FUND V^X^X tatONSTnEET, N.W..WASHINOTON. D.C. 2003G/?02 833 1-185
February 23, 1973
Mr. John Schcttino
Office of Noise Abatement and Control
Environmental Protection Agency
1835 K Street, N. W.
Washington, D. C.
Dear Mr. Schettino:
As participants in the Environmental Protection Agency's
Aircraft and Airport Noise Study Task Force, recently convened
pursuant to Sec. 1 of the Noise Control Act of 1972, we have
been invited to submit our views on the current agenda of the
Task Force, and to supply or identify materials which should
be before it.
I. The Agenda
With respect to the Task Force's agenda, we are deeply
disturbed by statements' made recently by EPA personnel,
concerned with past and present shortcomings of the FAA's
efforts at regulating aircraft noise, but only with recommenda-
tions for future regulations, and that the Task Force is to
avoid inquiries which might "embarrass the FAA."
As we read the Noise Control Act, an examination of the
adequacy of the FAA's efforts to date is required in the
plainest terms imaginable. Section 7(a) of the Act states:
"The Administrator [of EPA], after consultation
with appropriate Federal, State and local
agencies and interested persons, shall conduct
a study of the (1) adequacy of Federal Aviation
Administration flight and operational noise
controls; (2) adequacy of noise emission standards
on new and existing aircraft, together with
recommendations on the retrofitting and
phaseout of existing aircraft; (3) implications of
identifying and achieving levels of cumulative
noise exposure around airports; and (4) addi-
tional measures available to airport operators
and local governments to control aircraft noise.
He shall report on such study to the Committee
on Interstate and Foreign Commerce of the House
of Representatives and the Committees on
G-3
orricrs m- CASI scuimcr. MY (MMN orricci: NLW vonK CITV imimnAM suppont OFFICC); WASHINOTON. DC; DEnKtitr. CAUI .
Ihlt pep*, to raopcto* lii p/oftcf r/i» inrlmnmtnt.
-------
Mr. John Schcttino February 23, 1973
Commerce and Public Works of the Henatc within
nine months after the date of the onactmcnt of
the Act."
Section 7 (b) of the 7\ct makes plain that recommendations
for new regulations are r t to be made before -omplction of
this study of the adequa< . of existing FAA regulations. See
Section 611(c)(l) of the Federal Aviation Act, ;is amended
by Section 7 (b) . EPA har, already lost nearly l'»ur months of
the alloted nine,prior to setting up the Task Force. What
little time the Task Force has left should be devoted to
putting first things first, i.e., to studying the adequacy
of existing regulations, as Congress directed, before pro-
posing new ones.
II. Materials which should be before the Task Force
As to the question of identifying materials which should
be available to the Task Force and its participants, we
would begin by pointing out that this Task Force is by no
means the first governmental body which has considered the
problem of aircraft and airport noise. Accordingly, in light
of the severe time constraints on the TasJc Force, it is urgent
that the Task Force obtain and make conveniently available
to its pav-hicrpp^t!? materials nov.r in the hands of other agencies
which bear on this problem. We would start with the following
partial list of materials that are not currently in the Task
Force's files:
1. With respect to each type of jet aircraft now
operated or expected to be operated at American airports
(specifically including the Concorde SST):
a. Noise contours (not just FAR 36 measurements)
resulting from takeoff and approach, and the flight profiles
and flap and thrust schedules used to obtain these contours,
taking as a basis the actual procedures by which these aircraft
are operated by the various air carriers, and the actual ambient
temperatures and airport altitudes encountered, or, in the case
of aircraft not now in use, the actual procedures by which they
are expected to be operatedtogether with these actual temper-
atures and airport altitudes;
b. Variations in flight procedure (flight profile,
flap and thrust schedule, etc.) with aircraft weight, and the
accompanying changes in noise contours;
G-4
-------
Mr. John Schettino February 23, 1.973
c. Noise measurements at the FAR 36 takeoff,
approach and sideline measuring points, toqcther with the
flight profiles and flap and thrust schedules used;
d. Noise versus distance curves used in plotting
the above contours for each of these aircraft for:
(i) Takeoff thrust;
(ii) Maximum continuous thrust;
(iii) Thrust used after power cutback following
initial climb;
(iv) Thrust used on approach;
2. The transcripts and minutes of all meetings of the
Program Evaluation and Development Committee (PEDC) of the
White House Office of Science and Technology, which was
established in 1965 to study aircraft and airport noise,
including the transcripts and minutes of subcommittees formed
to report to PEDC;
3. All materials pertaining Lu aircictft and airport
noise or related matters in PEDC's files, including materials
submitted to PEDC or its subcommittees by members or consultants;
4. The transcripts and minutes of all meetings of the
Interagency Aircraft Noise Abatement Program (IANAP);
5. All material pertaining to aircraft and airport
noise, or related matters, in IANAP1s files including materials
prepared by IANAP's members or consultants;
6. All federal agency files (including those of DOT,
HUD, and DOD) pertaining to development and use of the concepts
Composite Noise Rating (CNR) and Noise Exposure Forecast (NEF);
7. The report (s) on distribution of costs resulting
from exposure to aircraft noise prepared by Prof. Paul Dygert;
8. The report (s) on the legal aspects of aircraft
noise regulation prepared by Prof. William K. Baxter;
G-5
-------
Mr. John Schottino February 23, 1973
9. The reports and other materials prepared by or in
conjunction with the Operations Research Project funded by
the Aerospace Industries Association and the Air Transport
Association (made available to the FAA in 1968 upon completion
of the project through its methodology stage);
10. The complete files of the FAA's Office of Noise
Abatement with respect to the draft Notice of Proposed Rule
Making on aircraft operating procedures for noise abatement
prepared in 1968;
11. The transcripts, papers, minutes and files of
the London Conference on Aircraft Noise Abatement in November,
1967, and the files of all federal agencies with respect
thereto;
12. A full set of all reports on aircraft noise or
related matters prepared for federal agencies by outside
technical consultants such as Bolt, Beranek and Newman and
Wiley Laboratories;
13. The complete files, of the FAA with respect to its
Advanced Notice of Proposed Rule Making (ANPRM) on Civil
Airplane Fleet Noise Requirements, 38 Fed. Rea. pp. 2769 RJK
seq. (Jan. 30, 1973), including:
a. All documents which discuss the reason for the
FAA's decision to make the proposed rule inapplicable to
"airplanes engaged in foreign [or overseas] air commerce,"
after the FAA's "working draft" of this ANPRM dated November,
1972 specifically included such airplanes within the rule's
coverage.
b. All documents which state or relate to the FAA's
estimates as to
(i) What percentage of aircraft at each of the
major U. S. airports would be exempt from
coverage;
(ii) What percentage of the fleets of the major
U. S. carriers would be exempt;
c. All documents which relate to the decision to
delete the sideline noise measurement from the proposed rule,
and as to possible tradeoffs between landing and takeoff
G-6
-------
Mr. John Schcttino February 23, 1973
noinc, on the one hand, and sideline noise, on the other,
with respect to each typo of jet aircraft now operated or
expected to be operated at.American airports;
d. All documents considered by the FAA in assessing
the environmental impact of the proposed rule, and weighing
it against alternatives, as required by the National Environ-
mental Policy Act.
14. All files, minutes and transcripts of the Aviation
Advisory Commission which relate to aircraft and airport noise
or related problems.
15. All documents in the files of the CAB which relate
to elimination of duplicative1 flights through implementation of
CAB-approved capacity limitation agreements among the airlines
serving a given route.
This list, of course, is not by any means complete;
rather it reflects the limited time available to us to date,
and will be updated as the Task Force progresses. But the
essential principle is clear: this Task Force cannot effectively
appraise the work of the FAA, as Congress has explicitly
required it to do, unless it has access to the same full
range of data available to the FAA.
Additionally, we suggest that a great deal of useful
information can be obtained, not from documents, but from
people who can be invited to address one or another of the
Task Groups and to answer questions from the participants.
Our initial list of such persons would include:
1. With respect to operating procedures that could be
used to achieve noise abatement;
Isaac H. Hoover, former director, Office of Noise
Abatement, FAA;
Capt. Paul A. Soderlind, former director of flight
operations (technical), Northwest Airlines;
Capt. Robert K. Baker, former director of flight
training, American Airlines;
Robert Myersburg, Office of Flight Standards, FAA;
G-7
-------
Mr. John Schettino February 23, 1973
George Moore, Associate Administr r for Operations,
FAA;
James Rudolph, i-i rector, Flight S lards Service,
FAA;
Joseph Ferreres- ChJ' Operatioi Division, FAA;
2. With respect to -i_r.- at of m impact;
Jaroes Woodall, Chief ircraft se Abatement,
FAA;
Karl Kryter, Stanfoi Research itute;
3. With respect to ceo1 ic aspect aircraft noise
abatement;
Prof. Paul Dygert, >.versity c ilifornia, Berkeley;
George Hunter, ChaV Planning If, Rocky Mountain
Region, FAA;
4 . With respect to .' eg -11 aspects «? Lrcraft noise
regulation;
Robert L. Randall, 3 -q. , Washir '"i, D. C. , former
Deputy General Counsel, FAA;
Prof. WiUiam Baxter, Stanford versity Law School;
5. With respect to t-r-clvoipgy avai le for aircraft
noise abatement;
Spiridon Suciu, Manager, Gas Tu; < ''e Technical
Research Operations, General Electric;
John Large, Director, Institute of Sound and Vibration,
University of Southampton, England (formerly 'n charge of
aircraft noise abatement for the Boeing Co.)
Due to the very short period of time av-<' lable to the
Task Force and its participants, we would af'i ' "ciate a response
to this letter at the earliest possible date.
G-8
-------
Mr. John Schcttino
February 23, 1973
Many thanks for your help.
Sincerely yours,
(
The Environmental Defense Fund
John Hellegors
Raclyn Janssen
Geoffrey Vitt
National Organzation to Insure
A Sound-Controlled Environment
Lloyd Hinton
John Tyler
Aviation Consumer Action Project
Noil McBridc
cc: Sen. Philip Hart
Sen. Edmund Muskie
Rep. Paul Rogers
Hon. Russell Train
Sen. John V. Tunney
Environmental Action
Catherine Lerza
James Conroy
G-9
-------
Rational Organization to Insure a^Sound-controlled Environment
Date: Feb. 27, 1973
To: Task Group 3 - Impact Characterization
Aircraft/Airport »oise Study Task Force
From:John M. Tyler, Executive Director, N.O.I.S.E.
Subject: Comments on proposed scope of activity of Task Group 3-
Impact Characterization of Noise Including Implications of
Identifying and Achieving Levels of Cumulative noise Exposure.
The EPA has invited participants in each task group to submit
recommendations regarding the scope and focus of the work of
their respective task group. This participant wishes to refer
to Public Law 92-57^ which specifies in Section 7(a) the work to
be done in the 9 month study and report to Congress. It states:
"The Administrator [of EPA], after consultation with
appropriate Federal, State and local agencies and
interested persons, shall conduct a study of the (1)
adeo.uacy of Federal Aviation Administration fliyii't and
operational noise controls; (2) adequacy of noise emission
standards on new and existing aircraft, together with
recommendations on the retrofitting and phaseout of
existing aircraft; (3) implications of identifying and
achieving levels of cumulative noise exposure around
airports: and (*0 additional measures available to
airport operators and local governments to control aircraft
noise, iie shall report on such study to the Connittee on
Interstate and Foreign Commerce of the Mouse of Representatives
and the Committees on Commerce and Public Works of the Senate
within nine months after the date of the enactment of the Act.:I
Section 7(c) specifies that the "EPA shall submit to the ?AA
proposed regulations (such) as EPA determines necessary to
protect the public health and welfare.11 This work is scheduled
for the latter part of 1973. It should not be confused -with the
9 mfcnth study being conducted during the first part of 1973.
The item in Section 7(a) which specified the work to be done by
Task Group 3 is ' (3) imolications of identifying and achieving
levels of cumulative noise exposure around airports;--". This
would seem to focus this Task Group's attention on the following:
1. Implications of identifying levels of cumulative noise
exposure vs identifying levels in other units, for
example, C/JR-, NEF or CNEL vs dSA, EPNdB, ASi?S or FNL.
G-10
-------
2. Implications of achieving specific levels of cumulative
noise exposure for various purposes sucn as acnievin~
compatibility with various land uses.
3. Implications of achieving specific level." of cumulative
noise exposure vs specific levels in ether noise units.
fl . Adequacy of the uata base for cumulative noise exposure
units including Cj.'n, J-iE?, SliEL, .H'.I , ?>.,,-\' , etc.
5. The agreement amonr established units of cumulative noise
exposure to achieve compatibility with various land uses.
The law requires in 7(a),the 9 month study, that the implications
of usin.-, cumulative noise excosure be studied. In 7(c) -./here
regulations are to be nroposed it would be appropriate to decide
on a specific unit of cumulative noise exoosure, specific not hod 3
of rr.onitorirr: and/or measurir.- aircraft noise and handlinn the data
to insure compliance v;ith noise limits, etc. If all of this v;ork
is attempted in the one month available for input to this 9 month
study the participants will be stretched too thin.
The law also reauires in 7(a) , the 9 month study, that the EPA
study the implications of achieving levels of cumulative noise
exposure. This asks the question, ''.vhy specific levels?" and
calls for the information available on cumulative noise exoosure
level vs compatible land use. It also asks the question, liov: can
specific levels be achieved, i.e., by what means technically, and
Vjir vtV-i^i- r-o p r> o T.7>^'-^T"1'» ~. y^ H *^4~ '.'^n*" r^^oi-O- r1Xn<-rt ^i>oc-+~^^vv^rt f ^, ^ rilc^/^
cLdivCU J.H ia.->i\ ut'faua t ditu 'j . ± u
the technical means for achieving specific noise levels and cost
would most lo-ically be handled by 'Jask Grouo ^ and the le;al, or
regulatory means for requiring the noise reduction by Task Group 5
Thus Task Groups 3, *» and 5 v;ill need to correlate the results of
their studies to answer the questions con^arnin" means and cost
of achieving specific levels.
Due to the lack of time since the first meetinr, of this Task Group
the details to be filled in under the five headin-s listed above
have not been vrorked out. This will be supplied as needed.
G-ll
-------
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
LANGLEY RESEARCH CENTER
HAMPTON. VIRGINIA 23365
March 12, 1973
REPLY TO
ATVN Of.
Dr. Henning Von Gierke
Biodynamic and Bionics Division
Aerospace Medical Research Lab
Wright-Patterson AFB, OH 45433
Dear Henning:
The attached w.i/aup entitled "Pure Tone Considerations in Measured
Connunity Koise" has been prepared to fulfill a writing assignment given
out at the second meeting of Task Group No. 3 of the EPA noise study.
Note that I was unable to reference the Canadian document on pure tone
evaluations that was discussed briefly at the last meeting. If a copy
can be furnished, it could also be incorporated as a reference.
Sincerely,
,_ -JkXi!«xVi»
-------
PURE TONE COHSIULU/vTICNS IN MEASURE CC^^HTY MOISL
A number of systematic studies have been performed to cvr. iu.vce i-l-.c
contribution of noisiness of aircraft noise due to the presence of pure
tone components. In this work a large number of human judgncntr. have
been made for noise levels representing those in airport conrauuities due
to low altitude aircraft operations, and the results of these judgments
have been correlated with various physical measures of the noise. These
measures have included A-scale, N-scale, and D-sccle data as well as a
number of EPNL units involving tone correction factors. The results fvc~
these studies as documented in reference 1 through 5 adequately support
the fact that a simple weighting system for the noise such as the A-sccle
system does not properly account for the noisiness of the superposed pure
tone components. It has thus been indicated that pure tone co:v-po».u:itt;
in aircraft noises can contribute substantially to noisiness juc.gr.-.ents
and are identified as worthwhile targets for noise reduction.
For noise certification of aircraft, units making special allowance
for pure tones are thus needed in order to properly evaluate the noise
for subjective reaction purposes. It may very well be found in r.oise
emission control considerations for other vehicles and items of equipment
that tones will also play an important part and may have to be properly
accounted for in certification procedures.
In community measurement situations, however, it is believed that
there is a lesser need for a measurement concept or system that especially
accounts for pure tone effects. The reasons for this judpnent are as
follows:
G-13
-------
a. Pure tone exposures of people in community situations are judged
to be generally short in duration compared to the overall noise exposure.
b. The proper application of noise emission standards for
transportation vehicles of all kinds and for industrial noises can be
expected to result in a relatively lower level of tone content in
community noises in the future.
CONCLUSIONS
1. A useful measurement procedure for cumulative noise exposure in
the community need not require tone adjustment factors. Hence, a
relatively simple system involving "A-scale" or "D-scale" measurements
is probably adequate (The D-scale is shown to be preferred based on
noisiness judgments.).
2. Evaluation units involved in noise certification and in noise
emission standards can be expected to require provision for pure tone
corrections.
REFERENCES
1. Little, J. W.: Human Responses to Jet Engine Noises. Noise Control,
vol. 7, 1961, pp. 11-13.
2. Kryter, K. D.; and Pearsons, K. S.: Some Effects of Spectral Content
and Duration on Perceived Noise Level. NASA TN D-1873, April 1963.
3. Kryter, K. D.: Review of Research and Methods for Measuring the Loudness
and Noisiness of Complex Sounds. NASA CR-422, April 1966.
G-14
-------
A, Pearsons, K. S.; lioronjeff, R. D.; and Bishop, D. E. Tiic Kolsincjc.is
of Tones Plus Noise. NASA CR-1117, August 19C8.
5. Pearsons, K. S.: Combination Effects of Tone arid Duration Para-.ctcrs
on Perceived Noisiness. NASA CR-1283, February 1969.
G-15
-------
CITY OF LOS ANGELES
DEPART',';E;;T OF Air;PORTS
. " 'I WORLD WAY LCS ANGELES CALII-OR.MA 9GOO9
c^....0 TELEPHONE I?U> 6.-.S.J2SJ . TELEX 6I.-341.I
March 2, 1973
Ref: AMRL/BB 16 February 1973
MOORE
-"" Impact Characterization of
Aircraft/Airport Noise Study
Task Force
Mr. Henning E. Von Gierke
Chairman, Task Group 3
Aircraft/Airport Noise Study Task Force
Office of Noise Abatement and Control
Environmental Protection Agency
Washington, D. C. 20460
Dear Mr. Von Gierke:
After a review of the summary of the first meeting of 15 February 1973
and my notes on the ineeting of 27 February 1D73, I feel that as an airport
representative comments are appropriate. The comments are submitted
in the recognition that the work that is accomplished in this task group
will have an impact on aircraft and airports and, also, on other forms
of transportation and city activities.
It would appear that prior to the meeting a decision was made that the
noise characterization and assessment method would have to be a wpighted
overall sound pressure level similar to the CNEL procedure. It appears
that this decision was reached with little consideration of ASDS or any
other simplified methodology. This may or may not be good, however,
there was a minimum of discussion. In considering the approach to rec-
ommending permissible limits, it appears again that the information was
to be presented in terms of percent of people affected with respect to
health and annoyance. There appeared to me to be only a passing reference
to previous studies attempting to correlate annoyances with sound level
frequency of operations and time of day. These studies, many of which
were done in foreign countries, should be reviewed in greater depth
before acceptance of their results as a guide for this group.
We would agree that the A-weighted decibel appears to be the best method for
measurement. When we consider that measurements and monitoring that will pro-
bably have to be accomplished and that the methodology should be as simple
G-16
IOARO OF AIRPORT COMMISSIONERS
Slrplu-n C. Rilhrimrr. fflf.S7W.VT Rnbnl M tfmm,./i. Hf\r C l,,nm,,r Mm.-AW . .if,/,./*/ />*, . h,nam f. & .!,..
-------
Mr. Henning E. Von Gicrke March 2, 1973
and least complicated as can be achieved, this method seems to be most
practical. When sophisticated measurements are required, EPNdb can
be utilized. In reviewing Dr. Galloway's working paper I question whether
or not a time integral of the sound pressure level in the A scale is a neces-
sity in all cases. Experience in California with SENEL indicates that this
complicates the process of monitoring and measuring. This is something
that should be discussed at the next meeting when we consider Dr. Galloway's
working paper.
We would agree that the tone correction is probably not necessary when we
consider monitoring procedures and acceptable cumulative levels. If pure
tone or spike frequency corrections are needed, EPNdb can be used for
the specific application.
We would also agree that a night impact number is possibly desirable and
feel that two periods per day is adequate. We would, however, suggest
flexibility in the night impact time. Somewhere between 10 and lip. m.
for the start of night impact and somewhere between 6 and 7 a. m. for the
end of night impact would seem most practical. This would seem to be a
decision that should be left to the local community to best suit their
specific needs.
Jn considering impact guidelines for all forms of transportation, I strongly
feel that Task Group 3 must consider the impact of all court actions to
date. While an idealistic approach to this impact problem may appeal to
certain individuals, I fear it does not recognise the facts of life in this
situation. ! think we all recognize that any regulation can be challenged
in the courts and successfully overturned. Therefore, to avoid a pro-
liferation of lawsuits and lengthy litigation, full recognition of past court
action should be a part of Task 3 consideration.
These are my comments on the Task 3 work effort to date.
Very truly yours,
Bert^J. Lockwood
Assistant General Manager
Operations
BJL:sm
G-17
-------
p o L T H E K A N l~: K AND N U W /A A N INC
f, i j ', U L T I N C, U C V L L O P M C N T RCS LARCH
9 H;irch 1973
-.os A N G r L r s o ; i i c i
2 i i 2 0 v A N o w [ ;j :. i 1.1 : i
CANOGA PAf:K. CAlliOf.N A 'M.n, $
TELEPHONE |213| 2 : 7 Ji :j t, ?
Dr. llcnnjng F. . Von Glerke
Chief, iilou;yn;;)iucs and Bionics Division
J'.j oifKvd ' ca.l Laboratory
Wright-Patterson AFD, Ohio
Subject: Ins :i.do/0ut side Noise Exposures
Dear Jicnn.in^:
You asked for somo sampler of inside and outside nolne
exponui'Co. 'i'hc attached sheet su;-i:nari:'.cs some typical
sii.ur.t.lons . Tiie datu v;orc? obtained from continuous
r.amulcs of A-lovcl with the LOq I'VT the day, evenir.r; and
ni^M- ppj'.i oc'.r: computed. Thc-se va.l.ucr. tire listed firi:t
in the t.-lile. I thr-n procoodod to calculate the I,en for
ti 2-i~!iCiU»' pt.'i'.i'. ^ ', .L . U . , ' HO 11 (J:. U V/.Li..^ pi.'!ii. ^ -^y ' -' <. .
noxl. f.o].i!!.:n T calcu latvd a '.;ei<;'ited exposure in v.'h.lch
day ;iMu evei!.' n, ; are cei..binod, but n.i[-;itt j.iao has a I,'' di3
pCTi'ilty o:-: K:V'..].. The lu.'jt column ii"> the same computation
with a 10 <_L'< .;ci ^htin^ on the ni fjjt tt lr::o ] ovclr. .
The inside levels for the first example ."residential/
suburban" may be a little high. The threshold was set
at about 33 dBA which resulted in an overstatement of the
Lgo values durinc part of the daytime period, a substantial
overstatement of all nighttime levels between 1:00 and
5:00 a.m.
Also note that the interior noise levels during the daytime
period in all cases are substantially affected by noises
inside the spaces; e.g., TV, talking, etc.
If you would like the information, I can give you plots of
the LI, LIQ, T.^Q > ^90 and Leq on an hourly basis for the
data on the enclosed sheet.
Sincerely,
William J. Galloway
VJO:bml
1-li.c.
G-18
HCW YORK
CHICAGO
LOS ANCEirS
f..V,' f I'
-------
\) - (>"(!>> " I '{'
['!/>.,:
O^'T'
;.,,'':>
D
r:
- VAC''
l-
e
O
/!.
".li'MO'
. L
i 6
/- to
-r
! l(,.u /.5>'io
7 :
7 '
---A
71.1,
o u T- _ O
I 1 i
; ^~
M ' ^\
i M ' D>
' S7.o :5.ox
i
SI,, RS/l
C.o y 10
G-19
-------
SEASONAL CHANGES
Submitted to Task Group 3 - b7 N-O.I.s.E.
Changes in weather brought about by changes in seasons have an
Important effect on the reaction of people to aircraft noise.
The most dramatic effect occurs in cities near airports at
latitudes where houses have well Insulated walls and well
sealed storm windows to keep out the winter cold. Good thermal
Insulation normally provides good sound insulation. When the
first warm days of spring call for open windows these houses
suddenly lose lOdB or so of outer wall sound insulation. The
complaints about aircraft noise on-these days every year in-
dicate the impact of this loss of outer wall protection against
noise.
There are at least two methods of handling this change in
impact of noise on people as a result of seasonal changes.
One method is to vary a noise weighting factor to compensate
for the variation in house outer wall attenuation. This
weighting factor would vary with the amount.of time the tem-
perature would be above the level at which doors and windows
would be open. This method indicates a higher weighted noise
exposure level when doors and windows are open. It has the
disadvantage that it is unlikely that the noise could be reduced
more in hot weather than in cold weather to compensate for the
weighting.
Another method of handling this seasonal factor is to rate out-
door noise on the same basis at all locations and take care of
the variation in outer wall attenuation at the local level in
noise and building codes.
G-20
-------
A standard for noise attenuation for house outer walls has been
developed in SAE AIR 1081. This AIR presents an outer wall
attenuation which is the average of four sets of attenuation
data. Two sets are for the averages of houses in cold winter
U.S. areas (New York and Boston); one for windows open and one
for windows closed. The other two sets are for warm winter U.S.
areas (L.A. and Miami); one for windows open and one for windows
closed. The houses in cold winter areas have more outer wall
sound attenuation than those in warm winter areas for both open
and closed windows. The difference presented in the SAE AIR
1081 between the New York and Miami houses is about 12dBA for
both open and closed windows.
Obviously houses built in other locations where building prac-
tices are different will have different out wall attenuation
levels. Also the magnitude of the temperature variation will
vary greatly with locations in the U.S. In the middle west
the winters are extremely cold and the summers extremely hot.
By comparison the coastal regions of southern U.S. are relatively
uniform in termperature throughout the year. Therefore any
correction factor for seasonal changes would have to be adapted
to the local termperature range and cycle.
At the local level it is necessary to establish land use zones
with noise limits to insure acceptable noise levels inside
houses. When this is done land use may be defined in terms of
building codes. Thus a house with an outer wall sound in-
sulation similar to the ones tested in Miami might be unsuit-
able in a New York area zoned for single family dwellings. And
G-21
-------
of course, another house or apartment building with more
outer wall sound attenuation and air conditioning could be
acceptable in a higher noise exposure area in New York.
Thus there are three factors to deal with in protecting people
in homes from outdoor noises :
1. No4se exposure level
2. House outer wall insulation
3. Variation in temperature which may,or may not,
mean variation in outside to inside attenuation.
It is felt that these factors are local problems because:
1. Where the seasonal temperature variation is small the
effect on people is small.
2. It can be minimized by house design practices,i.e.,air
conditioning or sound treated ventilation systems.
3. It can be handled by noise zoning practices,i.e.,
adjusting noise exposure levels to compensate for
minimum permissible house outer wall attenuation with
windows open so as to achieve a specified maximum house
Inside level.
Therefore it is recommended that noise exposure levels be
considered with respect to noise impact on persons living in
houses which have average outer wall attenuations and that
seasonal effects of noise be handled by the local zoning and
building code authorities.
G-22
-------
DETERMINATION OF INDOOR SOUND LEVELS
FOR JET TRANSPORT AIRCRAFT
29 March 1973
Prepared by
Douglas Aircraft Comapny
McDonnell Douglas Corporation
Long Beach, California
For Submittal to the
Environmental Protection Agency
Washington, D.C.
G-23
-------
29 March 1973
DETERMINATION OF INDOOR SOUND LEVELS
FOR JET TRANSPORT AIRCRAFT
INTRODUCTION
Currently, all methods in use or being considered for evaluation of aircraft
noise in communities around airports, e.g., References 1-4, use outdoor noise levels
measured at certain specified locations. The choice of an outdoor noise level
measurement was made on the basis of convenience and uniformity. Measurement of ir.c'cor
noise levels was not practical because there was no accepted definition of standard
dwellings in various climates and at various times of the year.
The results of various surveys made in communities around airports, e.g.,
References 5 and 6, have consistently indicated that the bulk of the complaints against
aircraft noise are due to interference with various indoor activities, such as
TV/radio reception, face-to-face or telephone conversation, and sleep. With the currer,t
emphasis on the cumulative noise exposure experienced by airport neighbors, it is
appropriate to consider development of methods to evaluate aircraft noise a_t the
actual location of the listener, i.e., indoors in the majority of instances. I& would
be feasible, in isolated cases, to actually measure the noise levels inside an
individual's home. For general application, it is necessary to utilize either
standard dwellings or to apply standard house noise reduction values to appropriate
outdoor noise measurements. With the recent development of standard house noise
reductions, Reference 7, it has become feasible to define generalized procedures for
estimating indoor noise levels based on outdoor noise measurements.
The purpose of this report is to describe the results of analyses of representative
aircraft flyover sounds and to recommend specific noise reduction values suitable
for interim application to the problem of assessing the response of airport neighbors to
aircraft flyover noise. The results presented here are intended only to give an
indication of the order of magnitude of the correct noise reductions. More-refined
G-24
-------
analyses would be required to develop precise values suitable for general applica-
tion. For an interim procedure, however, the results presented herein should be
acceptable.
ANALYSES
Measurements of the outdoor noise levels presented by two aircraft types
representative of jet transports in wide use and powered by low-bypass-ratio turbofan
engines and by one of the new wide-body transports powered by'high-bypass-ratio
engines were examined. The specific airplanes considered were the McDonnell Douglas
DC-8-55, DC-9-15, and the DC-10-10. The noise produced by the DC-8-55 should be
representative of that produced by other members of the DC-8 family powered by
short-duct versions of the JT3D engines and of that produced by the 707-320 family of
airplanes. Similarly, the noise of the DC-9-15 should be representative of the rest
of the DC-9 models as well as the 727 and 737 airplanes. The noise of the DC-10-10
should be similar to that of the DC-10-30 and DC-10-40 as well as the various models of
the 747 family and the L-1011-1. Thus, the three airplanes studied should be representa-
tive of most of the jet transports in use today.
For the purpose of this study, only the sound pressure levels (SPLs) at the time of
the maximum perceived noise level (PNLM) were examined. The 1/3-octave-band SPLs and
PNLM for maximum takeoff and for various distances were conveniently available as a
result of actual flyover noise testing for the selected aircraft.
The aim of the studies was to develop a method of estimating the indoor A-weighted
SPL, or the indoor sound level. This quantity is widely used for evaluating various
sources of noise, including, in some instances, aircraft noise, e.g., Reference 4.
Because of the transient nature of a flyover noise signal, the specific quantity selected
was the maximum sound level occurring during the flyover.
G-25
-------
Indoor noise levels for two different types of house constructions, with
windows open and windows closed, were calculated from representative outdoor noise
levels by applying the average noise reduction values from Tables VIII-IX of
Reference 7. Since these noise reductions were for 1/1-octave-band analyses, the
1/3-octave-band SPL spectra from the outdoor flyover noise measurements were first
converted to equivalent 1/1-octave-band SPLs before applying the house noise
reductions. Equivalent slow-scale A-weighted SPLs were then calculated from the
outdoor and the indoor SPLs using weighting factors from Table 1 of Reference 8.
Figure 1 shows representative outdoor SPL spectra and corresponding A-weighted
levels for the three selected aircraft, at a distance between the listener and the
aircraft of approximately 1000 ft, for maximum takeoff thrust. The large reductions
in low-frequency noise achieved by the new high-bypass-ratio turbofan engines at takeoff
thrust is readily apparent in Figure 1.
G-26
-------
RESULTS
Figures 2-4 present the results of the analyses in the form of the calculated
differences between the maximum outdoor and the maximum indoor sound levels as a
function of distance to the aircraft for the DC-8-55, DC-9-15, and DC-10-10
respectively. This difference represents the quantity that would be subtracted from
an outdoor sound level to obtain an indoor sound level.
Comparison of the results in Figures 2-4 showed a remarkable consistency in the
differences for the three aircraft. Inspection of the plotted values indicated that
single-valued correction factors for the four locations/conditions could be selected
to represent the power settings with a tolerance of approximately +_ 2 dB. Table I
tabulates the approximate values that were derived from the results shown in
Figures 2-4. The indicated trends are as expected with the cold climate houses having
larger noise reductions than warm climate houses and with windows open showing
significantly less noise reduction than windows closed for both warm and cold-climate
construction.
RECOMMENDATIONS
As an interim standard, it is recommended that the values shown in Table I
be used as the basis of developing a method of evaluating airport community noise based
on indoor noise levels. The house noise reductions of Reference 7 should be used as
the foundation for additional indoor noise studies, although additional refinement may be
needed to develop appropriate average noise reductions for 1/3-cctave band analyses.
(Development of these 1/3-octave-band noise reduction values should be feasible since
Reference 7 also contains basic 1/3-octave-band values.)
For the long-range approach, it is further recommended that evaluation methods
be developed that would be based on the concept of a suitable average standard
dwelling construction. Flyoyer noise analyses could be based on the use of a suitable
filter network whose frequency response would approximate the noise reduction of the
standard dwelling. G~27
-------
In developing new regulations governing allowable aircraft flyover noise levels,
the use of indoor noise levels Is considered most appropriate. As a matter of fact,
the use of indoor noise levels is considered to be better able to protect the
general health and welfare of the public than outdoor noise levels and to be less
discriminatory. Those dwellings that have good Insulation, are well-maintained,
have tight-fitting windows, or are alrconditloned will, by definition, have lower indoor
noise levels than those that do not.
Any new regulations, based on indoor noise levels, should, of course, also prevent
the escalation of outdoor noise levels. However, it also should encourage the wider use
of better construction techniques, acoustical insulation, and better windows. These
recommendations then, ultimately, should lead to the design of aircraft that minimize
noise exposure at the location of the listeners rather than at locations where there
rarely are any listeners, as is current practice.
G-28
-------
REFERENCES
1. Anom.; Noise Standards: Aircraft Type Certification; Part 36 of Volume III
of the Federal Aviation Regulations* Federal Aviation Administration,
Department of Transportation, 1 December 1969
2. Anon.; International Standards and Recommended Practices: Aircraft Noise;
Annex 16 to the Convention on International Civil Aviation, International
Civil Aviation Organization, 6 January 1972
3. Anon.; ISO Recommendation: Procedure for Describing Aircraft Noise Around
An Airport; ISO R507-1966, International Organization for Standardization
4. Anon.; California Noise Standards; California Depratment of Aeronautics,
Title 4, Register 70, Number 48, 1 December 1971
5. Committee on the Problem of Noise (Sir Alan Wilson, Chairman); Noise,
Final Report; Cmnd, 2056, HMSO, London, July 1963
6. TRACOR, Inc.; Community Reaction to Airport Noise, Volume I; NASA CR-1761,
July 1971
7. SAE Committee A-21; House Noise Reduction Measurements for Use in Studies of
Aircraft Flyover Noise; Society of Automotive Engineers, Aerospace Information
Report, AIR 1081, October 1971
8. Anon.; American National Standard Specification for Sound Level Meters; American
National Standards Institute, ANSI SI.4-1971.
G-29
-------
110
UJ
u
-I
Q
<=> K
4.
o
3
63
125
250 500 1000
OCTAVE-eANO CENTER FREQUENCY, Hi
2000
4000
8000
A WEIGHT ED
FIGURE 1. REPRESENTATIVE OUTDOOR SPl SPECTRA AT THE TIME OF THE MAXIMUM
PERCEIVED NOISE LEVEL FOR AIRPLANES AT MAXIMUM TAKEOFF THRUST
AND A DISTANCE OF APPROXIMATELY 1000 FEET
-------
40
O
CO
S
«
< UJ
8 Q
Z
58 20
11 1°
u- <
Q£
^> COLD CLIMATE-WINDOWS CLOSED
Q WARM CLIMATE - WINDOWS CLOSED
A COLD CLIMATE - WINDOWS OPEN
O WARM CLIMATE - WINDOWS OPEN
I
1
500 600 800 1000 2000
DISTANCE TO AIRCRAFT. FT
3000
4000
5000
FIGURE 2. DIFFERENCE BETWEEN OUTDOOR AND INDOOR SOUND LEVELS
FOR DC-8-55 AIRCRAFT (SHORT DUCT JT3D ENGINES), TAKEOFF THRUST
-------
40
8)
O
u 30
ss
O 3
8i
58
O "I
zo
UJ Ml
<*>$
s<
21
si
"- X
t<
OS
20
10
COLD CLIMATE - WINDOWS CLOSED
WARM CLIMATE -WINDOWS CLOSED
COLD CLIMATE - WINDOWS OPEN
WARM CLIMATE - WINDOWS OPEN
O
I
I
I
500 600 800 1000 2000
DISTANCE TO AIRCRAFT. FT
3000
4000
5000
FIGURE 3. DIFFERENCE BETWEEN OUTDOOR AND INDOOR SOUND LEVELS
FOR DC-9-15 AIRCRAFT (JT8D ENGINES), TAKEOFF THRUST
-------
40
*S?
5£
§i
if
30
Q
CO
CO
20
10
OS
V COLD CLIMATE - WINDOWS CLOSED
Q WARM CLIMATE - WINDOWS CLOSED!
A COLD CLIMATE-WINDOWS OPEN
O WARM CLIMATE - WINDOWS OPEN |
-A
o-
I
1
500 600 800 1000 2000
DISTANCE TO AIRCRAFT. FT
3000
4000
5000
FIGURE 4. DIFFERENCE BETWEEN OUTDOOR AND INDOOR SOUND LEVELS
FOR DC-10-10 AIRCRAFT (CF6-6D)ENGINES). TAKEOFF THRUST
-------
TABLE I - CORRECTION FACTORS FOR INDOOR
SOUND LEVELS
Amount to be subtracted from maximum
outdoor A-weighted sound pressure
Location - Condition level to obtain maximum indoor A-
weighted sound pressure level, dB
Takeoff Thrust
Warm Climiate - Windows Open 12
CoTd Climate - Windows Open 16
Warm Climate - Windows Closed 22
Cold Climate - Windows Closed 24
G-34
-------
TABLE I - CORRECTION FACTORS FOR INDOOR
SOUND LEVELS
Location -
Warn) Climate
Cold Climate
Warm Climate
Cold Climate
Condition
- Windows Open
- Windows Open
- Windows Closed
- Windows Closed
Amount to be subtracted from maximum .
outdoor A-v;eighted sound pressure
level to obtain maximum indoor A- ;
weighted sound pressure level, dD !
Takeoff Thrust
12
16
22
24
Approach Thrust '
13
19
27
31
G-35
-------
CITY OF LOS ANGELES
DEPARTMENT OP AIRPORTS
. 'I WORLD WAY LOS ANGELES. CALIfOR\'IA SOOOi"
\
wo TELEPHONE 12! 'Jl &4I>.52*2 TtLCX 6S- ?.; 1 J
March 27, 1973
ON A MOORE
MEMORANDUM
TO: Mr. Henning E. Von Gierke
Chairman, Task Group 3
FROM: Bert J. Lockwood
Assistant General Manager
Operations
SUBJECT: Task Group 3 Report
Attached is an exhibit print that was prepared in accordance with the
discussions at our last Task Group 3 meeting on March 20, 1973. As
it was necessary to place a large amount of data on a single print for
comparison purposes, I found it a'requirement to use a large print to
the scale of 1 inch equals 1,000 feet. It should be pointed out that this
is the type of data that is utilized in the various airport court cases. I
will bring 25 copies of this letter to our next committee meeting on
April 4 and I will be prepared to make a complete presentation on this
chart to the entire committee at that time. After your review I would
like to request that you bring this exhibit chart to our next meeting.
The following is an explanation of the information shown on the chart:
The boundaries of LAX are shown in blue, as is the runway layout. I
have also shown the extended runway centerlines and -the distance from
touchdown in the approach areas.
PNdb Contours. These contours are the result of studies by Bolt
Beranek & Newman and Wyle Laboratories under contract to the
Department of Airports. According to the reports by these acous-
tical consultants the contours are the result of field measurements
G-36
aoAH .'i o- .-.. -.f o ; i c; " :.; : *.; r-i
. I.' '.' till !{! Vi' V ' ' I, *,.':!. I i.'::' !/,.:.. .' ,' -, ...: . I-. .':.. .' "..I.:.. '! II
-------
Mr. Henning E. Von Gierke March 27, 1973
taken in the vicinity of LAX and represent actual conditions from flight
operations. The solid purple contour is the largest impact condition
and shows the 100 PNdb contour for the Boeing 707-320c. This can be
considered representative of this narrow bodied 4-engine jet transport.
The dashed purple contour is the 100 PNdb contour for the 4-engine
747-200 Part 36 aircraft. This demonstrates the great acoustical
improvement achieved by the new technology wide bodied aircraft
using high bypass engines. The green contour is the 105 PNdb contour
for the 320 Boeing and is generally representative of the narrow bodied
4-engine transport.
The 100 and 105 contours were shown as they seem to define the re-
petitive and serious complaint areas for LAX. The approach problem
area is best shown by the 105 contour, while the sideline problem area
from takeoff operations is best defined by the 100 contour. This ob-
servation results from a study of records of the Sound Abatement
Coordinating Committee.
Noise Exposure Forecast (NEF). The NEF studies were done for LAX
by Bolt Beranek & Newman in a series of contracts. They represent
a split of operations between the runway complexes of 65% on the south
complex and 35%.
-------
Mr. Herming E. Von Gierke March 27, 1973
Aaron Case utilized the NEF 40 for a sideline boundary, however, he
indicated no taking beyond Hass Avenue which is midway the length of
the 40 NEF contour. Even within the alleged take area in the 40 NEF
contour many plaintiffs were dismissed as they could not in any way
demonstrate a taking due to airport operations. Only in those cases
where a loss of value was demonstrated to the satisfaction of the court
was a small award made in this case.
As I had indicated in my previous letter and I feel is demonstrated by this
exhibit, when a determination is made as to the limit of acceptability of
noise we must be guided by court decisions if a truly acceptable methodology
is to be developed. As I indicated earlier, I will be ready to make a complete
presentation on this exhibit at the next meeting.
Very truly yours,
- v^""" > X
/ Bert J. iockwood
Assistant General Manager
Operations
BJL:sm
Attachment
G-38
-------
DEPARTMENT OF HEALTH. EDUCATION. AND WELFARE
PUBLIC HEALTH SERVICE
NATIONAL INSTITUTES OF HEALTH
NAT1ONAL INSTITUTE OF
April J, 1973 ENVIRONMENTAL HEALTH SCIENCES
P.O.BOX \1233
RESEARCH TRIANGLE PARK. N.C. Z7V09
Dr. H. E. Von Gierke, Chairman
TG3 EPA Aircraft/Airport Operations
Noise Study
Biodynamics and Bionics Division
Aerospace Medical Laboratory
Wright-Patterson Air Force Base, Ohio 45433
Dear Sir:
At the culmination of the last meeting, you made a request that a position
paper from HEW be prepared for this meeting regarding TG3's approach to
assessment of aircraft/airport noise impact. As we understand it, the
fundamental assumptions underlying TG3's approach are that both auditory
(hearing loss) and non-auditory (annoyance, physiological effects) effects
of noise are "sufficiently" approximated by the total sound energy experi-
enced over a twenty-four hour period. HEW is working on a position paper
but is not ready to comment at this time because of the short time span
available for preparation and the unavailability to us of the epidemiological
data from which the hypothesis that equal growth of deleterious health
effects corresponds to equal growth of total sound energy was inferred.
On a personal basis, I am enthusiastic about the concept of using some
form of frequency weighted total sound energy [Lvnqg] as an indicator of
noise environments, taking into account L^Eis simplicity, practicality,
and low cost vs. benefits. It seen\s a logical first step for a national
noise assessment program. I do feel very strongly, however, that language
should be incorporated (in whatever standard emerges) which would require
that noise dosimeters be equipped with readout algorithms such that one
could get at the cumulative L;^g at any time within, the twenty-four hour
time period. This feature would make standard setting possible on other
than a twenty-four hour 3 dB vs. doubling of time basis, within the same
measurement scheme.
And, along with some other members of the committee, I am inclined to be-
lieve that a D or N type frequency weighting scheme which discriminates
less against the low frequencies and emphasizes the mid-range will give
results which better relate to human response where health effects other
than hearing loss are concerned. If this scheme is subsequently adopted,
noise dosimeters would require two parallel systems, one for dBA with no
nighttime penalty and one with d3"DM and nighttime penalty, which brings
up an interesting question how will the nighttime penalty for non-hearing
loss effects, and the no nighttime penalty for hearing effects be handled
by the dosimeter as presently conceived?
Sincerely,
G-39
Reginald 0. Cook
-------
U.S. DEPARTMENT OF LABOR
Occupational Safety and Health Admrnis ration
WASHINGTON, D.C. 20HO
Office of the Assistant Secretary
APR 4 1973
Dr. Henning von Gierke
Chairman, Task Group 3
Aircraft/Airport Noise Study
Task Force
If. S. Environmental Protection Agency
Washington, D. C. 20460
Oear Dr. von Gierke:
Pursuant to the authority provided in the Walsh-Healey Public Contracts
Act, as amended, and the Occupational Safety and Health Act of 1970, the
Department of Labor has promulgated occupational noise exposure regula-
tions. These regulations are applicable to practically all employment
situations. Exclusions include employees working for a State or political
subdivision of a State and certain situations where jurisdiction is
included in that of another Federal regulatory agency. The requirements
of the Occupational Safety and Health Administration are applicable to
Federal installations per Executive Order 11612. When agreements are
effected between the Secretary of Labor and a State pursuant to the
authority in Section 18(b) of the Occupational Safety and Health Act of
1970, OSHA requirements could extend also to the employees working for
the State and political subdivisions thereof.
Current OSHA Occupational Noise Exposure limits are based on a cumulative
noise exposure during an 8-hour work day as determined by octive band
analysis or the equivalent A-weighted sound level. Permissible 8-hour
exposure is 90 dB(A). Greater levels are permitted for shorter exposure
levels.
The National Institute for Occupational Safety and Health has submitted
recommendations for changes to 29 CFR 1910.95 to OSHA. Comnents that
the current regulations are both overly restrictive for certain environ-
ments and that they are not sufficiently restrictive have been received
by OSHA. The NIOSH recommendation has been submitted along with others
to a Standards Advisory Committee on Noise. Committee recommendations
are due by the end of 1973.
G-40
-------
Page 2
OSHA compliance officers and industrial hygienists located thrcu-jr.out the
United States are responsible for enforcement of these regulations.
There has also been significant voluntary activity. Goals for ;,.cs;
occupational noise abatement programs are for reductions in noise to
no more than 90 dB(A) for all conditions. As indicated by CS:-!A
regulations feasible engineering and other forms of noise control are
preferred over the use of personal protective equipment. There have
been situations reported where noise abatement using only engineering
methods has caused or is causing some difficulties. Included are
situations where noise reduction technology is not yet available, where
noise reduction program is associated with a high economic cost, and
where noise reduction program introduces other safety and health problems.
In standards development and review activity, some of the considerations
that OSHA feels must be included in any evaluations performed are listed
below:
1. Assurance of safety and health.
2. Practicality of implementation.
3. Feasibility of implementation.
4. Enforceable
5. Essential
6. Introduction of other unsafe conditions and health hazards.
OSHA considers the points addressed in this letter relevant to the work
of the EPA Aircraft/Airport Noise Study Task Force.
Very truly yours,
Chain Robbins
Deputy Assistant Secretary of Labor
G-41
-------
COMMERCIAL AIRPLANE GROUP P.O. BOX 3707 SF ATTIE.'"ASM:: :o 5 TV; : : !
April 2, 1973
6-8400-RER-351
Dr. Henning E. von Gierke
Office of Noise Abatement and Control
Environmental Protection Agency
Washington, D. C. 20460
Dear Dr. von Gierke:
The Boeing Commercial Airplane Company appreciates this opportunity to
participate in formulation of the report which will be submitted to
Congress by the Environmental Protection Agency, as required by the
Noise Control Act of 1972. The purpose of this letter is to present
some Boeing comments on the EPA's Task Group 3 objective of characterizing
the impact of aircraft/airport noise.
The Boeing Company has encouraged and participated in the development of
methods for rating human response to noise. Several noise rating scales
have been developed in an effort to account for both the variability in
individual response to a given noise, and the multitude of different
sounds to which people are exposed. At present, no subjective scale
can provide more than a crude estimate of community response to a complex
sound, and experts in the field generally agree that no existing rating
scale can be identified as consistently superior.
Subjective scales developed for single noise events in the laboratory
have been used as a basic element in defining community reaction to noise.
Methods for extending subjective sound measurement units from single to
multiple sound intrusions have been derived from community surveys, and
have been used in the attempt to relate aircraft noise exposure to
community reaction.
Such community surveys have, however, indicated similar community reactions
for variations of as much as 10 dB in the cumulative noise exposure. This
variation 1s illustrated in the attached figure which was extracted from
the EPA Report to the President and Congress on Noise, December 31, 1971.
Social survey data (Ref. 1) have also indicated that noise alone is a ratner
poor predictor of airport community annoyance. From our understanding of
this and related data, we believe that any attempt to precisely define
community noise exposure limits of acceptability would seem to be premature
and arbitrary.
G-42
-------
Environmental Protection Agency
The Boeing Company recommends that the Federal Government accelerate
the search for a more accurate scale for defining connunity noise
acceptability, annoyance, or v/hatever term is appropriate. The
aviation industry urgently needs a reliable scale to use in the
initial planning of airports, aircraft, and aircraft engines in
order to insure a community acceptable design.
In view of the existing technology associated with relating cumulative
physical noise exposure to sleep disturbance, indoor and outdoor
speech interference, and subjective response, we have concluded that
the maaningfulness of cumulative noise exposure is questionable at
levels below those v/here hearing damage could occur.
We feel the above comments will be of value to EPA in preparing the
Task Group 3 reconwendations.
Very truly yours,
BOEING COMMERCIAL
AIRPLANE COMPANY
V. L. Clunenthal
Director, Noise and
Emission Abatement Programs
Reference:
(1) NASA Contractor Report liAS CR-1761,
Community Reaction to_Ai_rnort Noise, Vol. 1;
Tracer, Inc., Austin, Texas, July 1971.
G-43
-------
A Vigorout community
action
B Several threats of legal
action, or strong appeals
to local officials to stop
noil*
C Widespread complaints
Of single threat of
legal action
0 Sporadic oompiainn
Q
i
£
E No reaction, although
noise is generally
noticeablt
e
"~ C Or .»_: ft^».;_-.J .',./; V'ii- :: 9':-''- ''-';
f : V -~ '. "." ' LJ ''''''' -"''"
/, ,. >: '-;'. '.i^-**'
Mein . s: * :'.*r'
^\^ f . '' .-..--.:. ^
Env«lop« of 90% of Daia v .< '- "^* " r 'Jo '. ,y>
^S. f--:^': ;. ^ '. ' .: ^>
y
f. - . -* - . ' 'T - . -
t:ll$£^:: ' -:: - ->.VV
/. i ' ' '/
t >'' 'N,-.':;. ;.-./
^yi?0]ff:$^
f ^-^' V ::'::f
/- /
/ / /
A- / W
^ji&.t&t-ft J Data Normalized to:
/ '- p . j t.-.:- :.: t
A / /
/;. '.'.'; / Urban Residential RmoVial NoiiC
J' '' :,':'~ ':'": ',':'- '':' f '
^«*A/^: . ; f ..,-./ ' -'^^jf Some Prior Exposure
A:;;;:: ; ' f :::'J Windows Partially Open
S'- "' f No Pure Tone or Impulses
f,ft-!£::;&:-:':':::- :':::. '.-.:-i;V.vi / '
^v^v;f * a ^ ; 2 , O.l e
1 1 I ! 1 1 1 I
45 50 55 60 65 70 75 80 85 90
Normalized Community Noise Equivalent Level in dB
1 1 1 1 1 1 1 f
10 , 15 20 25 30 35 40 45 50 55
Approximate Nois* Exposure Forecast in dB
II 1 1 1 1 1 t 1
85 90 95 100 105 110 IIS 120 125
Approximate Composite Noise Rating in d8
Figure 2-9. Community Reaction to Intrusive Noises of Many Types as a Function of
the Normalized Community Nolaj.Equivalent Level
-------
= *
DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT
WASHINGTON, D. C. 20410
OFFICE OF THE ASSISTANT SECRETARY FOR
COMMUNITY PLANNING AND MANAGEMENT
IN REPLY HEF6R TO:
Environmental and Land Use Planning Division
April 13, 1973
Dr. Henning E. Von Gierke
Aircraft/Airport Noise Study Task Force
Office of Noise Abatement and Control
Environmental Protection Agency
Washington, D. C. 20U60
Dear Henning:
The following are my comments on the Douglas Aircraft Company report
of March 29, 1973, "Determination of Indoor Sound Levels for Jet Trans-
port Aircraft". This and the related reports and discussion on April ^,
1973, seem intent on forcing a choice between standards specific to the
indoor environment and those concerned only with external noise exposures.
It is folly to argue that one set of standards must be chosen at the ex-
pense of the other when experience tells us that both the indoor and the
outdoor environment are important considerations in establishing minimum
standards for aircraft noise. The obvious point, of course, is that one
must develop a dual set of standards plus information sufficient to com-
pute the degree of attenuation accorded by different types of building
construction .
is in the process of extending its standards into greater depth to
include a set of interior standards, which, in combination with exterior
standards, will define the degree of attenuation required in a dwelling
in order to meet the interior standards at various levels of exterior
noise. The above referenced report is laudable to the extent that it
furthers that goal. We welcome further work toward developing interior
standards as a complement, rather than as a replacement for exterior
standards, and in providing data on attenuation characteristics of alter-
native construction assemblies.
Sincerely,
James F. Miller
Director
G-45
-------
CIVIC CENTER
105 EAST QUEEN STREET / INQI.EWOOD. CALIFORNIA 9030!
March 26, 1973
Mr. John Schettino, Director
Regulation and Standards Development Staff
Office of Noise Abatement and Control
Environmental Protection Agency
1835 "K" Street, N.W.
Washington, D. C. 20460
Dear Mr. Schettino:
The City of Inglewood welcomes the opportunity of submitting to the Environ-
mental Protection Agency pertinent information, data and experiences relating
to aircraft noise. Inglewood will support the Aircraft/Airport Noise Study
Task Force in the effort to formulate meaningful aircraft noise standards as
mandated by the Noise Control Act of 1972.
We feel that the following steps should be taken without delay in order to
improve the compatibility between airports and neighboring communities:
1. Implement steep approaches under visual flight rules
immediately.
2. Implement steep approaches for instrument flight rule
conditions as soon as sp«cial navigational aids are
introduced to ensure a safe performance of the procedure.
3. Require jet engine retrofit for aircraft not meeting
FAR Part 36 standards.
4. Lower FAR Part 36 noise levels in time intervals to
provide for continued reduction of future jet noise levels.
5. Consider lowering of the present community noise equivalent
level (CNEL) criterion of 65 dBA as acceptable limit value
for residential areas. This criterion should not be
applied uniformly to all residential areas around airports.
MM:WAB:lm
OFFICE OF THE MAYOR
MERLE MERGELL
TELEPHONES: 213/674-7111
LOS ANGELES. 2)3/678-7221
-------
GENERAL DYNAMICS
Convair Aerospace Division
Kearny Mn
-------
AIR 12SG
llclioo{.'tcr and V/STOL Aircraft Noise Measurement
Tivis dv;i.'.'i :-.}.*'. <..-\< '. by
Commute-..- A-21/SAE Itr
clt-.l 21 tii^i. )!'T:": a.i:l
Go.';'1 '. '... Gcilinc
Chr.irinun, Si:!)-Co))]^iillco ot^
and V/STOI. Noise
submitted :!! .^'o
r l'.»72.
Conva'iV Aorospacc, MX (JHl'-
P. O. Box F-OS.I7
San Dic-D, CA 021;:':
Tel. (7M)-ii?7-Sl.)0(!/:;l-l?0
G-48
-------
AIR 1280
Helicopter and V/STOL Aircraft Noise Measurement Problems
PlirpOSC:
The noise signatures of vertical arid short takeoff and landing (V/STOL) aircrnlt
can differ substantially from those of conventional takeoff and landing (CTOL) aircraft
for which measurement procedures have been standardized. It is the purpose of this
document, therefore, to review the more important factors associated with the mc;i.curi.-
ment of external noise of V/STOL aircraft and to provide general guidance for the
acquisition and analysis of such data. In this document, the term V/STOL aircraft is
understood to include all aircraft which may operate in:
a. The VTOL mode, exclusively, where the aircraft takes off and lands
vertic-Jly and horizontal transition is m?.dc in the air.
\). The STOL mode, exclusively, where the aircraft takes off and lands \viU>
a relatively short ground roll and is capable of steep climbout and
approach angles.
c. The VTOL, STOL or CTOL mode.
These aircraft, therefore, include helicopters, till rotor configurations, propeller
and proji-fan aircraft, combination lift-fan and cruise engine configurations, and
various types of externalJy and internally blown flap installations.
Problem Are.-'is
1. ik-causc of the. wide variety of aircraft which must be considered, the acoustic
frecraoney riu^u of interest must bo extended well below thai presently con-
sidered for CTOL aircraft which arc for the most part powered by turbojet or
hirixji in 'n;;In-.%K. Tor i.-r-.-iniple, the rotor-rotational noise on large hclicoplc'j'.s
has i-i.'Lv;^!!.!!.1! <.',((.) :.[ ijifi-.i^onic frc'tf.icnc.lcs »':itli tho fundamental in (he .';di:;V
of ]0 If. !;.. ;:.-.. .:..:; :.;( '/> ;\ : ;\ ci! ...:' .iUy ;>.-j ri-,n:uli ,'u !!: I;M L: ('S .
G-49
-------
2. It is well known th:it the shape of the annoyance response* curve, reference oAK
AHPSGGA, is most lic;tvily weighted in the- frequency van^c from 3 to 4 kllx.. It
has also been shown that the preferred oetaves with 63, 125 and 250 ![/. geometric
mean frequencies, ai'c the most important fry in an aircraft detection standpoint.
However, it is the distinctly separable acoustical "events" taking plaee 10 to 20
times pci% second in rotorcraft thnt appear to elicit significant, subjective
reaction. It is therefore considered necessary to measure the fundamental and
lower order harmonics of the rotational noise, as well as the higher harmonic^.
to provide data for correlation with observed subjective reactions and analytical
noise prediction methods;. Information that can'be lost by a noise measurement '
system that does not have adequate low frequency capability, e.g. , suppression
of high crest factors, is shown by Figure 1.
3. An aspect of the noise measurement problem associated with some types of
rotor and propeller aircraft relates to the impulsive and impact characteristics
of the noise signatures. Impulsive noise it characterised by pulses of <..\lrem civ
short duratfon and extremely short rise time to their ma.xir.nmi levels. Rotors
emit high amplitude, modulated and repetitive impulse noise at relatively low
frequencies ac \vcll as at high freqv^n^ics. Propellers have si mil;'r character-
istics but at higher associated frequeue;e.s. Thus, to "capture" peak ampliluc-Lb
accurately, the acoustical data acquisition systems must have very wide frc";;n. ney
response and h:;,h crest factor capability. Experience indicates liut po-vc
measuring syrtfins such as Tins type.1 analyxmpf circuits anrl .^rnrhic level reeo: :::
are not .suited to analyxc and present sue!', data. Spectral displays lese relul:1. i-
phasinp. iaforniation, which aa ampliUide-limo hii.:tograp.i preserves, ho\vcver. A
systematic approach is noei'vd to develop eoninion dcseriplors :i;)d insirumcnl
systems for waveform cliaracleristies related to subjective response.
!. Another pniiOcm avea related 'n> \'/STOL aircraft r.oiso rnea.siD'emcnts ir. Die
probaMe, evcnlii'i' f;!::r.ii:ii".;: .:;'.ion of :ini.(-o iiie:i-;ureinO!''f. di^taivt1.1--. !'<')' iv-iin;'!i.',
> .,> ,~1.:-V; ..: ':'<" \ i) ..'' I. ''i 'r;'.-\' !-. ..[ I.:.I :! It.- . . t. li ! I. >. i! ' :,-.:;! r..: :. . :; . . .
G-50
-------
NGNIMI'ULSIVF
IMPULiiSVt
WA V [J OHMS
6pr"",
i
O
c-
i
w
W
SIANlJ/'l-iD L|i
VMCROi'HO.'l
LO/.
f.MCUOPHO;\'t
JOJ
TF-.ir:: - MILLISECONDS
; :()>/ .
f ,iLulii .':CY '
G-51
-------
nu'nt j.:cri meters for CI'OL tran;.;:wJ a/rcra.'t to as .sure- ti-.ac cala aro ;--.M:-O!Ml;iv
representative of t))0 acoustic far field. For rorrvniioriai t'..Ti :n:-crai't ^.- h
as the 707 or DC-9, for example, the.S'j </'.stances nuy :x> :;;-.'.if.k.L-;orv-. HOV.VWM-,
lor some types of V/STOL aircrau, sv;;;h ::s those \\hich r.n:-.ia oir.nioy l;ir-o
tilting rotor-props at the wing tip:.;, a ?CO foot dis'aniu? ir-av st.ll \r: in the aucn-.s'.ir
near field because of the physical separation of ..he various r-ois-": sciuvo;; .\::(-. ;'u
lonj wavolcnjjths associaleci with IVT\V f;'octucacy noise. ;)ei!'ae:;tk-.:\ oi'iiic iu/.n-ui-c-y
between the near and far fields may also be ifificuU for ;;i':cr:\;(. \viih 'r.rr.v
distributed, line noise EOUVCCS sucli as interr!ai!v l-Iev.-;: Hnp s'/stiMr,;;. T:-.i;:
situation should be thoroughly investigated before ;vv r,tler;i,:t at ?t;-..r. \v.i\-
lengths of the lowest frcrpiency of interest, whichever is ^rcuior. \V!v.i':j;-:- :-, .-..
criteria are valid for a large, distributed line source should be verified.
5. The one feature of V/STOL aircraft that, perhaps move than any other,
differentiates them from CTOL aircraft, is the use, in general, ol siy.iu: ioi r,,
of powered lift augmentation. This distinction holds true whether one- consul;-i-s
helicopters (as a class), configurations with blown flap systems, ii't iTii;.-v
engines or the use of lift fans, etc. For some configurations, fuch :i:- hcikx-i :.-::-
or aircraft employing tilt cruise fngiiics, (ho po\'.'i;r .sy.'.u-m whien i:- v,:;e'f
measurcmont of all the noise sources on the aircraf!. However, at muai-'urer.;' !ii
jioi.n'.s olo:-:i3 to the V/STOL jxjrt. cacli of tin- source.; in.-.y be civ.;-.:.'.';.:; its v.v.-e
ch^r.;c.UM-i..r.i>;;:; indt'liiiridi.-r.tly of liu- cr;'i..-r souivi;., ui. ;.:.'. ME :';:; .'.<.. ''.,}., .'. ' :;. : !
G-52
-------
m-ul'i!.'! .-MI »i |<:..\vcr (and noise) is :in tidditional variable in the description of
cur.;!'.-:- . i-.y .;;.!!:._. AJUio.;!;h (lie j;oul ol' Ihc ope nil or will lie that the aircraft i.r;
al\v;jy.--. :>," !.;< -ri in its most efficient and economical mode, tlic socio-economic
mnkci'.p of a community : it! j a. .-.") it to a V/STOL port or its topography may require
the imposition of certain operational noise constraints. Thus, it is conceivable
that on a given route a V/STGL aircraft might operate as a CTOL at one uirnorl,
as a STOI, at another and ;:s a V'J'OL at a third. Therefore, a meaningful noise
estimation procedure :'.nd measurement program will require that the temporal
characteristics ol' cacti of the noise sources be taken into account 1'cr all pote'.'.lU.i
terminal area and )o\v altitude criiisc'modcs of operation.
Processing of acoyisi/lc data involvin;; u-rv lov frcfiucncv and/or I'v-p'-'iiiiv,' i.-r ; :>:.e
or im;iact noi.'-;e .suouki be appro.-ichc'l \villi cruition. particularly v.v.orc the (':':
p.-otiai't of liio dni;! rotluetion process is to be a ptiLijociivo v.atitv., minibor SMC'I ;:;
Ei'fc-erivc Perceived Noise Level (EPNJ.K The EPXL rating irchemo was developed
on liii; basks 01" inroad hand noisL> corrected for diserc'le tones an'.! chi.'atio!1. ''.':
addition, the 'o\v; st onc-tliin! octave bravl cer.tcv fvi/v-ep.ey 'j;.i.;.i J-, rv:l is .".',...
The ('(iH'iriiiiv of oi)n'icti\'ehi 'li.ianlilyin.'c subjective :'( "-ponse to vc" :. liti'/o :::".. :- .
noi.'.'.:, siicl; a;-> helicopter rcUn bi:uic £l;:p, is renceU'd iiv the. Jaci ('':::'' r.o ;')';, i.
for :u-c e;)'al)ili'\' Iiave lj(>en ;?. i ''eel on. Similarly, \viiii 'e.t-"j)ecl to :"'0;.°e re M;'' i :.
fro'.M relatively hi^h jiropeller '. ;; speeds, i.e. , at ?.'acl'> nvP'-i'/er!-: ;\.'L\\t,-r tlvi-.
approM'mati'-ly O.S, the effect of i:iany hari^onicaily I'claled ton^- ; ha:-: noi i>e^ -.\
e\'a!ua(ed, aH!.o:i:;h it i? knov.n ihr.l. the ho.rinonic i elaLi.m.-:li:j).-3 S'v.'.ilic a:v! .-:: . 1
iMinoyance. TIK- i':;tal)li;;!:;iient o! cviteri -. it) this ,i: e:i i ; ^i::'';:.)':)!, b'-.riir;- ;-:' : :
can b^1 in;u'e l.>\\;ir.l.s '\-^i( n; ::: nr^'iieiler ' ; '((:(; !;.!!( . , i ! ;; '^Mi : :. ' lini.ve l.'-Vcl:--.
7.
i>Uj:'.;lsi\ v ;i'.'i:->r ;;('Ul'ee;;, i S that p',\ :)i'il,.;,ji_;;! Vi. ;.(:',.!. );1 (j.'.r,;iV
G-53
-------
the orxvjj, vcf. NASA lMo:iatron:iutits DaLa Hook, SP-.'iOOG, daicd 100 'I ami
"Compinifiiarn oi' Human Uc-uponscs to (he Aerospace F.nvjronmcut, " NASA CIl-
1205; Lovcl.-ice Foundation for Medical Education and Ret;cKirch, Nov. 19GS.
Discussion in this urea it; beyond the purview oT Lliis document. However, (he,
situation docs poinr. i;p Uic difficulty of extending Ibc cxistiiifr siilj.iccl.ivo r:iling
scheme for low froqueiicy anf! ir.i[)alsLArp noise. Vrr,.;trvcr nrocc- i. .'";_' mav lie
cvcntualh- cslai'li^h^c! it must, of cnurjx', fair smooth!;/ into otixT subiocTv-.'
ro.tinjt procedures.
8. No "best." dr.ta procof.sing sysUMii can bs define'.' for low frequency and irnpulsht..-
noise? at tliis tijnc since it will be dcpc.'ulent to a large o:.\tcrit on ihr riuUi recjuirc-
ments for whatever subjective rating scheme is eventually adopted. It must be
assured, however, that all recorded data are undistorted and tii.it the. processing
system enable. s complete retrieval and definition of lh:: inathematieai and
acoustical properties of the signals.
The above pavagniphs have described, in general, the more ir.'.ixr.'l.ini: pi-ob:c.:;i
aruas rebited to U'.K acquisition and processing of menu ingfui nyir-c data for
V/STOL aircraft. T))C ToUowin;; paragraphs deal v.ith special :nsf..-uinontaLi..n
recpjircmLM-ls. Where applicable, of course, ciat:;, i!i?f.rurnevii'r:.t;;iii, tcrJmiTJrs
and proccJureK dvseribc'd ir the SAE and ANSI c!oeu:'>'.cj.Ms H/;-. \v
frec(i!c:u;v :;: J/'^r :-op:?i;ir t in-;:ii!o(.' ih.iisc, ilie Jslia ;\c. r:sil:o:- iiv-.i.'-i." -nl.i'isp.
systcni ni'.u-L L.ive tin1. c:i;':ability of covci-jiv.1, (.he fix.".i-u-iicy r .).';:;; i'.c:-.. :: io .'. 1I/.
up to 11. 2;>0 I1/.: ami ;-;i ainplitndt: r.m-e iroiVi -10 lu 1::0 di'.. Mii.Ti.-.,,!.c.!i.^ an'
coinnuirci.-illy available, alone; with thuir aiu-il.'.'try r'lufpmfp.f, vl.ioii ';::>( the
l\'!i:i; ;\ t! >.',-:isitili;!y :i''.-v..-'- ti:. ». . '.' i i < .'a: . ;:.,>;.. f, ' ' r
G-54
-------
frequency modulation (I'M) recordi:v.; system should be used to assure adccf.iale
low frequency coverage. An ;i!'
low Irc'Cjiiency noit-e (say, below 300 II;:) in some detail, e.g. , in terms o!
FOUJ k-r h.ini'.unie.'; with ph-asin;;' of the lowest frequency significant periodic voi'.-^
in tho r;i.ivj.-'j. In addition, data .should be presented as l/o cctave band souiv.l
]5)-cs:nn t- le\\']i; .-iricl as A-weii;!.tod .sound level. Oicillogramr. (o convcv ih'-
pi ensure l-.i.-it-iry of a wave are also useful \vh'jro complex wavv.s arc involved,
a? 'in afriit!:-,!!:'! toc/l in the* evaluation of the p-svehe.itvriiislio -v-ffeels of a. nrm-
sii-usoida! \,'a\<-. Ii has not Iji-cn fiinclii.'.iv.'ly shown thai a complex wave can
be p-.\)];;M-ly rv.:U':ii(.'.i for ja;lijfctive annoyance l.y u:-.>. of a timulaiion Ixised
.sok-l\ on Ihi- ^'.'.nal'.'i !''o',u'it > harmonic com,>oncnls.
G-55
-------
Tim :iljovc discussion provides u brief summary nf tlic more important factors
rcl:dcil to noise mcasiu'enienlb of undefined V/fiTQI., aircraft types. These factors
arc in addition to those encountered in obtaining moaningfu) data on CTOL aircraft.
It appears tlint standard measurement procedures and d;ita prcscntaUou schemes for
vci-y )o\v froquoncy ^nd repetitive impulsive noise must wait until generally agroecl-on
subjective reaction criteria are developed. As in the e.'i.se of CTOL aircraft, it is
rcco{',iiized that thorr. may be factors other than the physical characteristics of the
noise signature that arc significant in community reaction. Consideration of these
non-ac:oni;tic factors is beyond (he scope of this document.
G-56
-------
APPENDIX
SAti COMMITTEE A-21 PUBLISHED DOCUMENTS
ARP 7.00 Measurements of Airci\ift Exterior Noise jn the Field.
AIR 817 A Technique for Narrow Bund Analysis of a Transient.
AIR 852 Methods of Comparing Aircraft Takeoff and Approach Noises.
ARP R6.1A Definitions and Procedures for Computing the Perceived Noise Level
of Aircraft Noisn.
ARP fiGG Standard Values of Atmospheric Absorption as a Function of Tcmpcratv.ro
and Humidity for Use in Evaluating Aircraft Flyover Noise.
AIR SVG Jet Noise Prediction.
AIR 902 Determination of Minimum Distance from Ground Observer to Aircraft
for Acoustic Tests.
AIH 023 Method for Calculating the Attenuation of Aircraft Ground to Ground
Noise Propagation Daring Takeoff and Landing.
ARP 10SO Frequency Weighting Network for Approximation of Perceived Noise
Level for Aircraft Noise.
ARP 1264 Airplane Flyover Noise Analysis System Used for Effective Perceived
Noise Level Computations.
and the foll'nviii:1; American National Standards Institute (ANSI) documents:
SI. 1-19(>0 Aeou.'iiical T.'srminoiogv (Including Me chanica.l Shock and Vibration)
Revision and Con soli d.i'Jon ol Z24.l-i.D51 and Z 2-1. la (ISO RIG, Rm,
and !!:0.10(0;-).
S1.2-10G2 Physical Measiivem.Mil oi Sound, Method for (Revision of Z2-L 0-15)30).
SI.!-!%! General--Pii!-i>ose Soum! Level Mc-)/:r.s, Specification for (Revision of
Z2-J..1-JU ;!}(! i-:c 12:;).
!'.' ':-. -I : : .: :,.'.! IV'.-,-' Na'.V.! : l'.; f'.V A(\::.:(JC'.il :.;.:..-..; ' ,:< .'...:,
(A-;: -.:'. ..;.. r-o i.:..-.;..:}.
G-57
-------
til.3-l.9GU Prefer rod Reference Quimtifcio;; I'-M- .V-uus-.i'vul Levels.
S1.10-1DGG Culihnitiuti uf Microphone's, M."lhod for t-'ac- (, He vis ion :xnc! Coiisolididion
ol ZLM.-l-lH-rJ and 7.2-1. 11-!'.):"!).
Sl.ll-r.lGO Octnvc, Hii.f-OcU-ve, ;mtl Tlurcl-Oc:t;;vc H.-uul Filter Sets, Specificalion
for (Ile\i.sion and Re-designation of 7,2-1.10-iar,;;)(Ii:C 225).
G-58
-------
DEPARTMENT OF THE NAVY
NAVAL UNDERSEA CENTER
SAN DIEGO, CALIFORNIA S2132
IN REPLY HE PER TO
9 May 1973
MEMORANDUM
From: Robert W. Young
To: 11. E. von G-ierke, Chairman, EPA Task Group 3
Aircraft /Airport TfoisG
Sub-j: Material i'or report on aircraft /airport noise
End: (l) Symbols and abbreviations in noise control
(2) Glossary for noise environment
(3) Definitions of environment noise level noise dose
1. The number of symbols and abbreviations that will be required for
the subject report is sufficiently great that a separate appendix for
that purpose would be very helpful. I offer, enclosure (l) as a frame-
work for such an appendix, and as the list of symbols to be used in
the main text. Only letter symbols ought to be used in equations, but
abbreviations are also provided here for those who may want them. For
symbols that should be added to the list for quantities in the most
recent Task Group 3 draft, I suggest:
iJdn
D
A
day-night average sound level (DNAL), an average
A-weighted sound level for a day, with nighttime
levels increased 10 dB
difference in A-weighted sound levels; same as noise
.level reduction (NLR)
noise dose, the equivalent duration of exposure to a
criterion sound level. The unit is a time unit, or a
percentage of a rating time
2. Dictionary-style definitions for many of the terms encountered in
noise control are given in enclosure (2). I offer such a glossary as
an appendix to the report_, to be selected for terms actually used in
the report. I suggest adding the definitions of enclosure (3), for
environment noj.se level and noise dose .
oung
G-59
-------
Hay-night average sound level. An average sound level during 24 hours, with a
ten-decibel weighting of noise during the night from 10 pra to 7 am. Technically,
the day-night average sound level is a time-weighted mean-square A-weighted
sound pressure level
noise dose. The equivalent duration of exposure to a given criterion sound level.
The rule of equivalence between sound level and duration must be somewhere indicated.
A noise dose may be expressed as a fraction, or a percentage, of a rating time such
as 8, 24, or 40 hours.
The noise dose of a succession of sounds is the sum of the noise doses of the
individual sounds. The noise dose D, as a fraction of a rating time tr, can be calcu-
lated from
D = tl/T1+ t2/T2 ... = tn/Tn, (1)
where t^ (standing for t^, t£ ... tn) is the total time within a period of observation
during which the sound level, A-weighted, is near a given level L , and T. is the
permitted duration of exposure to the given sound level L . In principle, a "give-
sound level" is simply one of a continuous distribution of sound levels, althou' . j-t
may be practical to change the level in steps of one or two decibels. The sv . in
equation (1) is to extend from a ratio ^±/^± that is small at low sound .1 » .1 (where
1/T.£ is small) to the ratio t^/T^ that is small at high sound levels (< .' .re t^ is small)
-(L - Lr)/ n,
The "permitted" duration T.^ is calculated from T. = tr^> where tr is a
"rating time" such as 8 hours, and Lr is the corresponding sounr? V-ivel for which the
rating is to occur. The exchange rate between sound level r.>r>. duration of exposure is
n, given in decibels per halving of permitted duration /^. For example, if n = 3 dB/
time halving, T.j_ will be halved every time L. if xticreased 3 dB.
The required information can be supplied, for example, by a label for the
reading x of noise dosimeter, in the form x % 8hr 90 dB A5. This means a noise dose
of x percent of 8 hours equivalent duration of exposure to 90 decibels A-weighted sound
level with an exchange rate of 5 decibels per halving of duration.
G-60
RWY: 10 May 1973
-------
Reprinted from NOISK/NLWS 1, 124 (1972)
Quantity Symbols and
Abbreviations in
Till* liii i\ lii-ini; />ii!>l!\licil In' ciiitncsy <>J Dr It W. Ymnif.
Art:<./ Undcr\ca ('filter. Sun DI'CK<>. Qiliforniti '."".
Symbols ami abbicvialions loi sor.ie qnaiiiilios cncomUcied
i,! nniic control aie listed below I he lei lei symbol appeals
IkloiL ihc name of llie quantily: a capilal-leiici abbic\ Kiiioii
suiiable CiM computer piinimil is given in paicnihcses.
As explained in "I eliei Symbols (01 Quantity Symbols used
in Hc.-iii, ..I Science and hlccnical I 'npnceiing." Aineii^.in
Naiion.d Si: iul.ini VI 0.5 I'KiS. when pnnseil ijiiatiniv N\III-
Ivv: appeal in il.ilics. Quantity .ib.'ucMalions. in conli..s(
v.'i:li i|ii;iiiiity s\inl)i)ls. :ne pnnteil in roin:m (VCIIK-.I!) ivpe.
An ;ilihi'-'\i;iiidn I'or :i unit the unit synihol is ;ilso printed
in .ii:n:-ii l\'j". ;inil j'.cnci.i!!)' in sni:il! letiei::. 'I he !ir>t lettei
uT ihc synihcil. Ivnvcver. is a e:ipil;il il Hie unit is deiiveil
lu.'iii :i pinjiet name: lor example, the unit ol liequeius is
tl;e boil/ anil the unit symbol is II/. The lie I ('inil sy:iib'.>l
li) i.-; a unil ol level: pieeeih'ii by l!ie sl-indari! vviulit'l lui
the pieliv ileei. Ihe nun synii)ol li'!, bill if 11 is
pu'ct'.lcd bv ;i iiuinUei. the \rnii syniiol ni.iy lie usfil.
l:\iimples: . . . the sound level was 1'2 dl!: si;iiinl level is
ni'.'asined in decibels.
level (!.) of a kind defined in an accompanying
text.
acceleration level
velocity level
displacement level
sound picssmc level (SIM }
sound level, A-wciglucd (SLA)
sound level, A-weiphicd. last iesponse (SI..AI")
sound level, A-weighled, slow response (SLAS)
impn'se sound level. A-weiiihtcd (SLAI)
sound level, A-wek'hied, inaxinnnn (SLAM)
sound level. A-wci[;hlcd. inininuirii (SI.AN')
ratinp sound level, being the sound level A
adjusted for spectrum character and
duration (RSLA)
ten-pereeiitilc sound level, the A-weightcd sound
level equalled oi exceeded 10',' of time
modi;in sound levrl. the A-weirjiled sound level
equalled or exceeded SO'.' of lime
equivalent sound level. A-weigiitcd (SLAQ)
a
/.
'A
/-A.
/A,
/-At
'so
re
noise exposuie level (Nl:l ). the tinie-imcpralc:!
A-weighled sound level
houily noi.e level (IINI 1
houily noise level. da> lime (IIN'l I))
houily imise level, evenin-' (IINI I )
hourly noise level, niphi (I1NI.N)
sound level. C-woiglnod (SI (')
(icl.ive band sound prewne level (OlSSl'L)
onc-thiid oclave band sound pressure level ('K)liSI'l
noise pollution level (N'I'l.)
perceived noise level (I'XI.)
peieeived noise level, in.ixnnuni (I'Nl.Ml
l^ereoived noise level. loiiC' conceled (I'NI I)
clleclive peueived noise level jN'NI )
oclave band OddS in :, '
releience sound po\vci . I p\V
relercnce sound pressine loi -:..>.. 20 /jl'a
releieik'C sound piessuie loi h(|iiid. I /d'a
lelercnee \ibialoryaeceieialion. I0/jm'<-
leicieiK'O vibi'iUoiy vviloeiiy. 10 m>\,'\
lelereiiee vibiaioiy displ.ieei'.ieni. 10 pin
ailiculatioii index (Al )
foinniiiniiy noi.se equivalenl level (v'NI.I '
hearing level (111.)
noise ciiU'iiou level (XC1
noise exposuie forecast (Ml )
noise induced pennaiKiil llneshold shift (Nil' ! S)
noise induced lemporaiy ilncsliold shift (Nl I iSI
noise level (Nl.). ihc A-weiuhied sound level of
airho'.uc s
noise reduclion (N'R). icduciion in :,ound piessine
level for a staled fiequency 01 band
noise level reduclion (NI.R). reduclion in
A-wcighled sound level
noise isolation class (N'l(') beiv.een rooms
pcrmancnl llneshold shill (1'TS)
prefened-ivequcncy speech inieifeicnce level
(I'SIL)
"willi releience to" a .slated iplerence qnaniil>'. loi
a level
sinple-evenl ni)ise exposuie level (Sl-N'l I.I
sound transmission class (STO of a pai liiion
speech inleifeience level (SI I.)
lenipoiaiy thicshold shill ( ! IS)
threshold shill (TS)
7'///v list /v " i:i>tiM>lit.laii'j>i. con'ccli-'//. ami cx/itinsia/: »/ ihc
//.v.'.v that appeared in iWl.W/MWS. 1. 10. (>!. (l>)'/2). /:',{.
G-61
-------
Reprinted from NOISE/NUWS 1. 39, 40, 62, 63 (1972)
Glossary of Terms
for Navy Noise Measurements,
Particularly for tha Environ-
mental Protection Data Base
(This marrri.il is being putilishsti courtesy of Dr. R. W.
Young. /Vjiv/ Undersea rt-.'i-;-*rch and Development Center!
acceleration l.wel. In dc.-ibcU. 20 limes the logarithm to the
b^se ten of the rdiio of vibratory acceleration 10 the rrfeitMce
accderatio.-i.
corirr>'j:iity rums cuuivalen1. level. Average noise level over
2'1 iiours. i'.'it;-! Nv no:s. In ellrcl, the composite noiic rating is the
m,i> i'Uvjm perceived iioive level at a given location due to a
ti'pic.a: fircrafl operation, minus 12 decibels, plus 10 lime:;
til-.- co.r.mo'i IrK'-.-iir.m o: the numrjer of aircraft operalions
f'oni 0700 hours K> 2200 hour:, (davl plus 17 times the
nuniixr of operations from 2200 hours to 0700 hours
(ivcjht). If it is yrean.'r, the composite noise rating based on
r-.ir.Lp noise, ana similarly steady sounds, is to be used.
This cornpjiiie noise raiiny (here with a 20-decibel increase
alrt':ir,'y incUirloc! ;o permit ciirect comparisons) is the typical
P'jrr.eivjd noise level of ll-.e viLr.r.oiy d:-. I'L.eir e it \<
the icfercnOL' vibratory ri':-:''l.i; onu- it.
effective duration. [>ur2iiun e? ;i r;-.:is:.i:it i,;i.ii>:i v.hi."'r. ,T.
tm- maximum itv.in;! nr-.»_v,iie level c:l ,i I!-IH< v..'; cone;-
rjoncls to an («.( lid'iiie rale lic-tv.c-er. sound i'i:-> >u !--vel i',ii
lime, of 3 li'i'Oels lor a douhiiu'j of ii:w. str'..-'.v.,i u.'i..
rrt elfi'ctive du.'.i'.iC'ns follow liom o;:iei e\c h.>i'. :. i.i-rs
eUcctive perceived noise level. Time-integrated p: tct.-ivj'J
noise level calculjlrd wnh adjustmrnis ir>r :'i e;.:l,,ri'.n-1 in
the sound fpeclum. sucn cs caused hy (rs-'-i-;,' licr.ui.'iir.y
components. The re'crence liiii; is !0 KVO^.'V The ur.r;
of effective perceived noise l.-vu! is tl'O drcibe', but fcr
clsrification it is commonly tagjod by an ubbTvijtic-n for
effective perceived noise: fxi.mi.lc. 90 fPNUB. Hffc-ct've
perceived nor.o level is often derived fmn1. lorv.i-conrcud
perct'i\'L\i ifvi-i calculated ft'. 0.5 second intervi-ls.
A
equivalent duration. Of a time varying sound, thp duration
of n constant reference sound of slated sound PIC-SMI re lc\-i?l
lh.it would convey the same- tounc.' energy in a civen sound
field as does the varyir.g :our,d. The energy equivalence
corresponds to an exchange late, between sound piessure
level and time, of 6 di-cibsli icr b dcublir.y cf t.me'. Other
exchange rates may be specified; for example. ;v.-',ordiog to
one. rule for dfsfness ri-.k the efft,:tivt
duration of sauna at various levels is caled-.M i for the
eq'jivc.'c-.t A-we;>|l'icd sound level of i>C decih.-!-, and :"
exchri~.gc> r;.;e of 5 decibels for a doubling of time.
equivalent sound pressure tavel. The constant sour,.; prei. IM^
le/el equivalent to a varying sound presr-i.'ie levol djring a
stated sample time, tquivalencc is usually bas-'d on an e:<
change between sound ptcssurs level and tuna ,it tl\e r.i'.i; ot
3 decibels for a doubling of time; in tins cav;, the cquiva
lent level is .the timj-Tieaivsn'Jcre sound pressun; levr-l ov;r
tho sample tin.e. The riite of 5 decib'.'ls for doubling of time
is empfoyed in some cfe.ifness risk tables
-------
frequency. Number of complete oscillation cycles per uiii;
of time. The unit of frequency often used is the hcru (Hz).
frequency band. Difference in hertz between the upper and
lovv?r frequencies that delimit a band, or the interval in
octaves between the two frequencies. The bjnd is loc&tid
freciu^ncy-wii.'1 hy the geometric mean frequency Li'tween
the two band-edge frequencies. An example is "an octJvs
band centered at 500 Hz."
hearing threshold level, hearing level, hearing loss. For an
impiired ear and for a specified signal, the amount in
decibels by which the threshold sound pressure- level for
\\iAl ear fixcivds a standard threshold of hearing.
hertz. Unit of frequency equal to one cycle per second.
hourly noisi level. The average noise level during the hour.
Moic specifically, for airborne sound it is the mean-square
A-weiglued sound pressure level over tiie hour. The unit is
the decibol (dB).
impulse sound level. The A-weitjh'.ed sound level measured
with the faster detector-indicator characteristic specified
in "Additional requirements for '.he measurernr.nl of im-
pulsive sound," 1972 supplement of IEC Publication 175:
Precision sound level meters. The unit of impulse sound
level is the decibel (dB). Use of ilic characteristic must be
indicated, such as by: the impulse sound level was 78 dB;
the limit is 78 c!R |AI); LAI = 78 dB.
inverse first power. The variation of squared sound pressure
inversely as the first power of distance from a long line or
cylindrical source.
inverse square. The variation of squared sound pressure in-
versely as the square of distance from a point source.
level. For communication and acoustics, the logarithm of
the ratio of a giver, quantity to a reference quantity. The
base of the logarithm, the reference quantity, and the kind
of level must he indicated. The unit of the level, such as the
decibel. «.ervos to identify the base of the logarithm includ-
ing any constant of proportionality.
loudness. Tho intensive attribute of an auditory sensation,
measured in senes. Calculated loudress of a sound is ob-
tained by a stated empirical rule from the sound spectrum
in octave or third-octave bands.
loudness levci. Of a sound, numerically equal to the sound
pressure level of a 1-k.Hz, frontaily-presen'.ed tone subjectively
judged equally loud. The calculated loudness level of a sound
is the weighted ^ound pressure level obtained by a stated em-
pirical rule from the spectrum of iht> sound in octave or
G-63
third-octave bands; the calculated loudnnss leval is a pivJ.crcr
of ttie loudness level that would be judged in c psvchopl-.y^cti
test. The unit of loudness level, judged or calculated, is the
phon which is equal to the decibel.
noise criterion level. The octave band sound pressure level at
1700 Hz of a noise criterion curve (NC - curve) that at one
of its frequencies is equal to the maximum octave band level
of a noise.
noi»e exposure forecast. For aircraft noise, at a given loca-
tion, the effective perceived noise level there for a typical
operation, minus 88 decibels, plus 10 times the common
logarithm of number of aircraft operations from 0700 hours
to 2200 hours |day) plus 17 times the number of operations
between 2200 hours and 0700 hours (night). The unit cf
noise exposure forecast is the decibel, although it is omitted
in usual reporting in the form, foi example, NEF--30. For
some typical aircraft flying at a distance of a fe'.v thousand
feet, when 6 percent of operations occur at night jc.cl 20
'percent in the evening, the noise exposure forecast plus 3b
decibels is nearly equal numerically to the community noise
equivalent level (CNEL); at greater slant ranges, phis 33 in-
stead of 35 decibels.
noise level. For airborne sound, the sane as sound level
unlcs; otherwise identified.
noise pollution level. The average sound level of a sufficiently
tong sample of noise, plus 2.56 tirr.ts the standard Deviation
of the sound level. The average sound level is the timo-iiua^-
square A-weightcd sound pressure level.
noisiness. Subjective magnitude of judged noisiness due to a
sound. Calculated noisiness of a sound, in noys. is obtained
by s stated empirical rule from the sound spectrum in cc'.ave
or third-octave bands.
noy. Unit of noisiness either judged or calculated. One noy
is the judged noisiness caused by a frcntally-presonted octave
band of pink noise centered on 1 kHz of 40-dB sound pres-
sure level and duration 0.5 second.
octavr Interval between two sounds whose frequency ratio
is 2:1.
one-third octave. Intsrval between two sounds whose
frequency ratio is 2^:1, nearly 5:4.
perceived n6ii» level. A frequency-weighted sound pressure
level calculated by a stated empirical rule from the spectrum
of a sound in octave or third-octave bands for a duration of
0.5 second. The unit of perceived noise level is the decibel,
but calculated perceived noise level is usually tagged by an
-------
abbrcvuiti.vi for perceived noiso: example, 98 PNdB. Judged
perceived nciv: level of a sound is numerically equal to th-i
tound pressure level of a frcntally presented octave band of
pink nois'? centered frequency-wise on or.p kilohert; and
duration 0.5 tocon.J that is <:'.ibjoctive!y judged equally noisy
in tlif: sen so of "unwantedness." Perceived no:se level (cal-
culated is physical predictor of judged perceived noise icvi.'l.
plotting format. Pioportion of s:zes of scutes used 0:1
ci'-iiodtc utitj abscissa of a graph. For graphs in which a level
in drvib:'!? is plotted against Ircquency on a log.vithmic scale.
t!v Icngih for the factor of ten in frequency is preferably 50
millimeters: it must lie equal to that for 25 decibels (pre-
ferred) CK to bO or 10 decibels.
power level. In cio-cibels, ten times the logarithm to the base
ten of ini! u.tio of ;j sound power to the reference found
power of one piccnvdtt (or.e-millionth of 'a v/altt.
prefc'red frequency. A frequencs' whose magnitude is one
of the Rr. n.ird wics of preferred ruribsrs that includer.
1000, ur.Mblly a frequency in the 10-series spaced at inter-
vals of nearly cne-thiid octave.
w:nple time. The tou.l tim,; curing which a varyinn sound
P";c.:ro ';-.:: :; measured.
signrl-io-'iCM.".!? level. The amour.',, in decibels, by which L
jlvon signal level exceeds o reiitud noise level.
sound exposure level, noise exposure level. The level of sound
acr.i.imulaiod during a ';nts of Am<-ri'":'i Np'.io,-;n
Standard Specificjiion for S:".'nd LC'.fl Mcteis, 51.4-1!'-71.
Sound love! is the frequcncv-vnighiffd sount! ;.'.-.^n-' lo«a.-l
olrtiiincrl with tnc st,''"ui;,rdi?-.'J dynnmir cl.iir '.::> iis.ti;' "i;..t
01 "slow arid w-'ighting A. B, or C. unless ijiji-.MU'd ol!-,:1-
wise, the A-v.eighting is untli'Tstood. Tluv IM.H of any of '.;::
sound kve's is the decibel. The A-v.'iiighiN.j ::-.'!;t:s the
sound-level meter relatively less sensitive to l.'uv-frocj'.icricy
sound, somi,".vii,->t ;ii tno way the e.ir is pro:;:<;v..;vcly less
sensitive to sounds of frequency l.olow 1 kl'i/. The C-
weighting givi:s the- S'.v.ina' k-\> i nu'tt-! ,i cor'.i.un f.»nsiiivit\'
in the fiequcncy rnnce 32 to MOO Hz.
sound pressure level. In d;.vi!i:'!s, ?0 t:i:rb I'.-e lr-i.:tio of a SI-;I:K! >. s.v.;ro to ',' ".'U'.-i1:-.,--.-
sound c-.Tfvji'.'. 1 r.e leicri'ru-e prrr/.'-ure lot ;'i''.:-j: ne ,:ivl
is 20 nncr.Tp^...:.is ( 20 .^-irM'-'C'v.H)"!- ,--.-: ; i.1--- :r.-::-i !
(0.000? ni;'.rcl-,:r). For vv.T.crboi nt- sound the- is.-kri.i.-i:
pressure- is one- m'cro:5,iscal. In ti-.r
ribjSnce of any modi Tec. ti'.i1 level is unjjts'.ooi' :;, '^j jlK:',
of 3 me?'i-sq'.';.re pressure, /it: ex,H!-v;i'.' o'.lui,-.i:,- is ;\',,K
sound pressirc- level
speech interference level. For :i tourd tn.Ti lu-.-sit invi
with unou-rstjndii'ici ^DO'lch. ;hi; iiritr.rnctic n>" '> o; c."..
band sou-.d pri'syue levjls. in d"cib-:!s, .cnf. ,:il nn !>0\
1000, and ?OC'0 H;-. For many s->unc:? i>. is 7 c!.)' i '.-.-..nn i
sure levals i:i the lliree octavt-s from iVOO to '\/J'.l H/. .
times with thr- ;icici::ion of the level for tin- ;vii..i 3C1C lo c
Hz. The preseiitiy^jjcd banci: are centerod on rve-erra
frequencies: h^nee tho name prcferroc:-freci'.:epic, spic:;i:re lovi?l ,~t
the rate of six decibels for ear.h (ioubling of distance from r.
point source of sound.
G-64
-------
TO: Dr. H. E. von Gierke 10 July 1973
Chairman, Task Group #3
Aircraft/Airport Noise Study Task Group
Environmental Protection Agency
SUBJECT: Alternate Method for Considering the Effect of Average Sound
Level on Speech Communication
FROM: Daniel L. Johnson
Member, Task Group #3
In the early stages of preparing the Task Group #3 report, I
submitted a paper on the "Percentage of Time Speech Interference Hill
Occur for Various Ldn Values". This was incorporated as the appendix
on speech interference in the first draft version of the document.
The paper basically recommends some maximum sound nressure levels
for various listening conditions, then predicts the amount of time the
environmental noise intrusion will be above these sound pressure levels.
One of the drawbacks of this method is that no direct accounting is
made as to how many dB the intruding noise exceeds such recommended
sound pressure levels. Nevertheless, the methods do present a completely
different way of analyzing the effect of environmental noise on speech
communication. I/hen this method is used as a basis for recommending an
environmental L
-------
Percentage of Time Speech Interference
Will Occur for Various L, Values
an
1. Method of Prediction
a. In order to investigate the effect of using actual noise profiles with
respect to time, the 18 statistical descriptions of daytime noise (pages 18 or
p
49 of Community Noise ) were plotted on probability paper (Fig. A-l). This plot
describes the range of PIx when all 18 noise profiles are used. Fig. A-2 shows
the range of the possible error that could occur when the 18 noise profiles are
approximated by the single profile in which (1) Leq = L,Q, (2) L-.Q - Leg - 10 dB
and (3) the statistical distribution of level with respect to time is normal.
Note that Fig. A-2 is generalized so that only L (the A weighted level for a
5 C
certain speech criteria) can be evaluated with respect to any outdoor Leq level,
The effect inside a house is found by assuming some value for the house noise
reduction (NR,).
b. From Fig. A-2 it is rather apparent that the possible error increases
substantially once Leq-NR, is equal to or greater than the L under question.
The variability is so large, in fact, that it is questionable that Leq alone
can be used as a reliable measure of PIx under this condition. For a
less than the L in question, however, PIx can be estimated with a very
w C
reasonable degree of accuracy.
c. Since much of the variability of the predictions is due the noise
profiles in which aircraft noise exhibits a strong influence, an analysis was
made in which aircraft or other non-typical noise was eliminated. This was
accomplished by eliminating four noise profiles where single event noise from
aircraft predominated. These were profiles F, K, M, and R (see Attachment #2).
The ocean noise (profile E) was also eliminated as non-typical. Fig. A-3 is
the result of eliminating these noises. Note that for Leq-NRh less than the
G-66
-------
L , there is little difference between the results of Fig. A-2 and Fig. A-3. The
j w
range of possible values of PIx is still quite large once Leq-NR. is greater than
the L . From the above analysis, it doesn't seem to serve any purpose to separate
5 (*
noise profiles with high aircraft noise from noise profiles in general.
2. Manipulation of the Data in Order to Provide Basis for Selecting a Leq Limit
Based on Speech Interference
a. Consolidation of Information of Para. 1. Table A-l has been constructed
in order to summarize the predicted effects previously discussed.
b. Selection of Exposure Situations. Three situations have been selected for
discussion. These are exposures that occur (1) outside, (2) inside a standard
house with windows open and (3) inside a standard house with windows closed. A
house noise reduction value of 15 dB is selected to represent the window open
condition and a NR, value of 25 dB is selected to represent the windows closed
condition.
c. Criteria for Speech Interference. Two different measures of speech
interference are suggested. The first measure comes from reference 1 (Attachment
£1). The breakpoint between good listening conditions and fair listening
conditions is 47 dBA. This value was rounded to 45 dBA for the purposes of this
report. The breakpoint between fair listening conditions (Attachment #1) and
just acceptable speech conditions is 56 dBA (55 dBA will be used).
2
The second measure comes from Fig. 19 of the Community Noise . Table
4b--l is a summary of Fig. 19.
d. Table A-3
As the first step in recommending an exposure limit measured in Leq,
the data of Table A-l has been incorporated into Table A-2. This table shows the
effect of different exposure limits on PIx. The exposure limits selected to be
analyzed were Leq's of 55, 60, 65, and 70 dBA.
G-67
-------
e. Selection of Listening or Speech Conditions. The first crucial assumption
that must be made is that different listening conditions are appropriate for
different living situations. Less speech interference snould be acceptable
outside a house than inside, for example. For this reason, it is suggested that
different listening and speech conditions be allowed the three different living
situations. One set of reasonable conditions are listed in Table A-3. T'^-ere-
were some interactions among the three living conditions as an attenot was -::ade
to make the difference between the recommended levels 10 dB (between windows open
and windows closed) and 15 dB (between windows ooen and outside). This made the
outside condition slightly less desirable.
f. Table 4 is another way of looking at the data that is somewhat different
than the approach of Table 4b-2. It is obvious that the information in Tables
A-2 and 4b-l can be manipulated in many ways; but in the final analysis the
decisions that must be made are (1) what is an acceptable listening condition and
(2) what is the maximum percent of the time this listening condition should be
exceeded? Once these questions are answered, the Leq limit is determined. The
Leq limit can be converted into L . limit by L^n = Leq + 3 dB.
G-68
-------
Figure A-l
-30 -
NOISE PROFILES OF 18 TYPICAL COMMUNITY
NOISES DURING THE DAYTIME
i
O
PROBABLE PERCENT OF TIME A Lx-Leq VALUE WILL BE EXCEEDED
-------
Figure A-2
PERCENTAGE OF TIME NOISE LEVEL
EXCEEDS A SPECIFIED L
sc
100
80
60
UJ
o
QL
LU
40
0
+20
-10 0 +10
Leq~NRh~Lsc
NRh= HOUSE NOISE REDUCTION, IF ANY
SOME SPECIFIED CRITERIA LEVEL
OR MAXIMUM BACKGROUND NOISE
LEVEL FOR CERTAIN SPEECH OR
LISTENING CONDITIONS.
dBA
L
sc
G-70
-------
Figure A-3
PERCENTAGE OF TIME NOISE LEVEL
EXCEEDS A SPECIFIED L
sc
100 i-
80
H 60
z
LU
O
cc
LU
0- 40
20
I
+20
-10 0
Leq"NRh"Lsc
NRh= HOUSE NOISE REDUCTION, IF ANY
SOME SPECIFIED CRITERIA LEVEL
OR MAXIMUM BACKGROUND NOISE
LEVEL FOR CERTAIN SPEECH OR
LISTENING CONDITIONS.
dBA
sc
G-71
-------
TABLE A-1
L*q - NRh - LSC
-15 or less L will be exceeded much less
than 1% of the time (« 1%).
-10 LSC will be exceeded less than
1% of the time (< 1%).
- 5 Lsc will be exceeded 2 - 5% of
the time.
- 0 LSC will be exceeded 8-30%
of the time (6 - 30% if aircraft
noise is also considered).
+5 LSC will be exceeded 30 - 90%
of the time (11 - 90* if aircraft
noise is also considered).
+10 or greater The variability is so great that
more about the noise must be
known. Leq 1s not enough.
G-72
-------
TABLE A-2
For General Noise Without Aircraft Noise*
Leq Limit of 55 dBA
L 45 50 55 60 65 70 75
s c
Inside - Windows Closed « 1% « 1% « 1% « 1% « 1% « 1% « 1%
Inside - Windows Open 2-5% < 1% « 1% « 1% « 1% « 1% « 1%
Outside ** 30-90% 8-30% 2-5% < 1% « 1% « 1%
Leq Limit of 60 dBA
L 45 50 55 60 65 70 75
5 C
Inside - Windows Closed < 1% « 1% « 1% « 1% « 1% « 1% « 1%
Inside - Windows Open 8-30% 2-5% < 1% « 1% « 1% « 1% « 1%
Outside ** ** 30-90% 8-30% 2-5% < 1% « 1%
Leq Limit of 65 dBA
L 45 50 55 60 65 70 75
o \*
Inside - Windows Closed 2-5% < 1% « 1% « 1% « 1% « 1% « 1%
Inside - Windows Open 30-90% 8-30% 2-5% < 1% « 1% « 1% « 1%
Outside ** ** ** 30-90% 8-30% 2-5% < 1%
Leq Limit of 70 dBA
LS(, 45 50 55 60 65 70 75
Inside - Windows Closed 8-30% 2-5% < 1% « 1% « 1% « 1% « 1%
Inside - Windows Open ** 30-60% 8-30% 2-5% < 1% « 1% « 1%
Outside ** ** ** ** 30-90% 8-30% 2-5%
Attenuation assumed - 25 dBA Windows Closed
15 dBA Windows Open
*Aircraft noise can be added changing 8-30% to 6-30% and 30-90% to 11-90%
**Range of variability too great for useful prediction
G-73
-------
TABLE A-3
Living Condition
Inside House
Windows Closed
Raconmiendod Listening
or Speech Condi c~i_o_n _
(1) The listening conditions should
be "good" as defined by >T-ference
1. This good listening ~o?u.nt:ion
is at or beirw 45 dBA.
(2) That relaxed conversation ccvi
occur up to distances of 12' per
Table II. This is also ;>t
dBA.
Inside House
Windows Open
(1) The 1 isiQir. nq condi ti on:" -;-;< ; ;
be at least "fair" as d^in^: by
reference 1. This fair 'lisu .-li-.t
condition is defined to be c-, -\r
below 55
(2) That conversation can oro;r.-
distances of !?' with -\ .MK
voice level- This wil: occ
levels at Oi- below 55 ri;
-------
TABLE A-4
Leq Limit 55 dBA 60 dBA 65 dBA 70 dBA
Percent of Time Conditions
of Table A-3 Will Be « 1% < 1% 2-5% 6-3Q%
Exceeded (PIx)
G-75
-------
References:
1. Beranek, L. L., W. E. Blazier and J. J. Figwer, "Preferred Noise
Criterion (PNC) Curves and Their Application to Rooms," J. Acoust.
Soc. Alter., 1223-1228 (1971).
2. "Community Noise". Report prepared by Wyle Laboratories for the
U. S. Environmental Protection Agency, Report No. NTID300.3,
December 1971.
G-76
-------
Attach #1. From Preferred Noise Criterion (PNC)
Curves and Their Application to Rooms
Beranek, Blazier and Figwer, JASA,
pp. 1227, (1971).
T.Mtt.K II Kri'MHunrntlril c.ilc^orv cl.issihr.M inn and s\iu^fslctl
rioKo rni rri.\ r.n-cr f'»r sir.v l\p I >;tc ground noise as heard in
varimi* indoor i'\i;;riiniul :icliviiv areas.
Typo of spare (and acoustical
n-'jiiirrim-nlsl
1'NC curve
Approximate
"oncrrl halls, opera houses, and 10 to 20
renl.'.i lull- i.i»r liMennn; lo
fatnl uni'-rcai snund-i
nrii.ulr.isl and recording slu- 10 lo 20
dios (distant microphone pick-
up ii-ed)
t,.'ii'|;c audiNiruims. lar^e drama Not to exceed
!hca;crs. and churches (for ex- 20
celleiil iis'.cnini; conditions)
Uro.vk.i'.l, leU". ision, and record- Not to excccci
i»K studios (close microphone 25
pickup only)
Small aiuhior mnis. small thca- Not to exceed
ters, small churches, music re- 35
hcarsal rooms. iart;e meeting
and conference rooms (for cood
listening), or executive olhces
and conference rooms for 50
people (no amplilicalion)
Bedroom* sleeping q»iarlcrs, hos- 25 to 40
jiilais. residences, np.irlnienls,
hotels, motels-, etc. dor sleep-
ing, resiin;,-. rcl.Tjine^
Private or scmiprivatc olTiccs, 30 to 40
small con!cfc;'.ce rooms, class-
rooms, iiliranes. etc. (for pood
listening conditions)
Living rooms and similar spaces 30 in 40
in dv. el!ir.£s (for conversing or
listening to radio and 'i V)
Laryc oiliccs, reception areas, re- 35 to 45
taii r-hops and s! ores, cafeterias,
rest.T.Ir.ir.:s, e'.c. for moder-
ately i;oocl listen.n;; t (inditions)
Lohhies. ialioralory >-. ork spaces, 40 !r> 50
(Iraftnj* and en;;inecnnp
rooms, ccnerai secretarial .areas
(for i.-!<' lisicninf; conditions)
Li^hl m.iiiitLn.incc shops, of- 45 to 55
ficc and computer equipment
rooms, xi'chcns, and laundries
(fnr n>ndcra'elv lair listening
conditions)
Shnps. carafes, pnwcr-pianl con- 50 to 60
trcl rooms, etc. (for just nc-
ccplniilr speech ant! telephone
communication). Levels above
Pj\C"-60 .ire not recommended
for :>ny nfl'ice or communication
situation
For w;irk spacer, where speech or 60 to 75
telephone communication is
not required, hut \vhcfe there
must Ix: iio risk of hearing
dsrr..?.f;0
21 lo.lO
21 to 30
Not to exceed
30
Not to exceed
34
Not to exceed
42
34 to 47
38 lo 47
38 to 47
42 to 52
o 56
.52 to 6:
066
O-77
-------
10
20
50
~r
LCCATFCN
A 3rd Floor Apartment, next to Freeway
c
D
E
;
G
H
:
l
N
O
P
G
R
3rd Floor Hi-Rise, Downtown Los Ange'e;
2nd Floor Tenement, New York
Urban Shopping Center
Popular Beech on Pacific Ocean
Urban Residential Necr Major Airport -
Urban Residential Necr Ocean -
Urban Residential 6 mi. to Major Airport
Suburban Residential Near R/R Tracks -
Urban Residential
Urban Residential Necr Small Airport -
Old Residential Near City Center -
* 4
-Aircraft Takeoff
Suburban Residential at City Outskirts
Small Town Residential Cul-de-Scc
Smell Town Residential Main Street ~
»
Suburban Residential in Hill Canyon
r * \ / I
harm in Vcl ley
Aircraft Overflight
/V;ain Street Trc*fic
Canvcn Traffic
Grand Canyon
North Rim)
iiar-.tseei r.c Aircraft"
H 80 Percent ~~
of Date
L99
90 L50 10 L]
±
[0
20
) 40 50' 60
A-Weighted Outdoor Noise Level in dB re 20
90
Figure 7. Da-'time Outdoor Noise Levels Found in 18 Locctions Ranging Between the Wilderness and the Downtown City,
with Significant Intruding Sources Noted. Data are Arithmetic Averages of the 12 Hourly Values in
the Daytime Period (7:00 a.m. - 7:00 p.m.) of the Levels Which ere Exceeded
99, 90, 50, 1O and 1 Percent of the Time
-------
APPENDIX H
POSITION PAPERS SUBMITTED BY TASK GROUP 3 MEMBERS
WITH RESPECT TO FINAL DRAFT REPORT OF TASK GROUP 3,
DATED 1 JUNE 1973
Summary and Evaluation of Position Papers Submitted By Task Group 3 Members
Or Organizations With Respect To The Task Group 3 Report (Draft 1 June 1973) by
Dr. H. E. von Gierke, Chairman, Task Group 3.
Letter dated 30 June 1973 from Edgar Shaw, President, Acoustical Society of
America.
Letter dated 26 June 1973 from Raelyn Janssen, Environmental Defense Fund.
Letter dated 28 June 1973 from Reginald O. Cook, National Institute of Environmental
Health Sciences, Department of Health, Education and Welfare.
Letter dated 2 July 1973 from Gene I. Martin, Aerospace Industries Association
of America, Inc.
Letter dated 2 July 1973 from William B. Becker, Air Transport Association of
America.
Letter dated 2 July 1973 from J. Donald Reilly with attached comments from the
Airport Operators Council International.
Letter dated 26 June 1973 from Clifton A. Moore, City of Los Angeles, Department
of Airports.
Letter dated 30 June 1973 from John M. Tyler, National Organization to Insure a
Sound-controlled Environment (NOISE).
Letter dated 29 June 1973 (6-7270-1-443) from V. L. Blumenthal, Boeing Commer-
cial Airplane Company.
Letter dated 20 June 1973 from General Aviation Manufacturers Association.
Letter dated 2 July 1973 from K. O. Ingard, Institute of Noise Control Engineering.
Letter dated 2 July 1973 from R. S. Gales, Department of the Navy. Letter written
by request of Acoustical Society of America.
Letter dated 29 June 1973 from Clifford W. Graves, Department of Housing and
Urban Development.
H-l
-------
Letter dated 18 May 1973 from Robert S. Bennin, Director, Bureau of Noise Abate-
ment, City of New York. (Per telecom with Daniel L. Johnson, letter still applies
to the 1 June Final Draft Report).
Letter from the Department of Commerce concerning the Aircraft/Airport Noise
Task Force.
Letter dated 29 June 1973 for A. L. McPike, Douglas Aircraft Company.
H-2
-------
SUMMARY AND EVALUATION OF POSITION PAPERS SUBMITTED
BY TASK GROUP 3 MEMBERS OR ORGANIZATIONS WITH RESPECT TO THE
TASK GROUP 3 REPORT (Draft 1 June 1973)
by
Dr. H. E. von Gierke, Chairman, Task Group 3
This Appendix contains all official comments and position papers received by
20 July 1973 on the 1 June 1973 draft of the Task Group report. Additional and more
detailed comments made by various Task Force members and subsequent Task Force
discussions at the 21-22 June 1973 Final Task Force Meeting at Washington, D. C.
are a matter of public record at the EPA Aircraft/Airport Noise Study Task Force
file. As a result of the comments received up to and at the 21-22 June 1973 meeting
minor changes and clarifications were incorporated into this final version of the
Task Group report. However none of the conclusions and recommendations of the
report were changed. Therefore, although some of the minor comments might have
been incorporated or superseded, no changes were made in the final text which could
have changed the basic positions or the principal issues as expressed in the letters
collected in this appendix.
Most of the basic technical positions addressed by the position papers can be
categorized with respect to 4 main points.
(1) The adequacy of the single measure selected (L, ) to measure cumula-
tive noise exposure with respect to public health and welfare as directed by the 1972
Noise Control Act.
(2) The use of A-weighting to account for the importance of some frequencies
over others.
(3) The recommended immediate goal of reducing all residential noise
exposures to a L, value below 80 dB.
(4) The suggested long-range goal of reducing the yearly average L, in
residential areas to values below 60 dB. n
The following table gives an approximate summary of the responses with respect
to these issues, although it is strongly recommended that the reader evaluate the
positions for himself by studying this appendix. The positions are summarized only
to respond to some of the criticisms and opposing views.
It is important to note that there was hardly any disagreement with respect to
the Issues 1 and 2. This is of great significance since this agreement includes
concurrence on the important conclusion that aircraft noise exposure must be
measured and evaluated by the same yardstick as environmental noise exposure from
H-3
-------
other noise sources. (The comments by the EDF and NIH with respect to the prefer-
ence to "D-type weighting" is considered a minor issue at this point and adequately
covered in recommendation 1 of the report).
With respect to Issues 3 and 4, the key issues and starting points for the reali-
zation of any effective national noise control effort, it is surprising and gratifying
that the analysis and approach taken by the Task Group resulted in as much agreement
as documented. I fully accept the criticism that the Task Group did not quantitatively
analyze the economic impact of achieving the goals recommended for environmental
noise levels adequate to protect public health and welfare. However this point is
clearly discussed in the report as being beyond the scope of the Task Group and it
is for this reason that the Task Group does not recommend a time schedule for
achieving the goals. It only states that achievement of the intent of the Noise Control
Act of 1972 "to promote an environment for all Americans free from noise that
jeopardizes their health or welfare" requires in the Task Group's opinion promotion
of the goals listed as Issues 3 and 4 in the Table. The report states that the time
schedule for achieving these goals must be based on a detailed analysis of the economic
impact.
The technical criticisms dealing with Issues 3 and 4 deal with the inadequacy of
the data base for these recommendations, with the alleged disagTeement among experts
and with the need for additional research prior to formulating such goals. These
criticisms are the same ones which have been expressed on these issues over the
last two decades and which prevented concerted national efforts, goals and planning
for only too long. It is expected that the same criticisms would be heard and could
be expressed no matter how much additional research data would be accumulated.
I think the difficulties of identifying and selecting maximum noise exposure levels
to protect the public health and welfare are clearly discussed in the report, its
appendices and references. Decreasing the obviously existing scientific margin of
uncertainty between noise exposure and its effects on health and welfare will not
solve the main and basic problem which is a social, ethical and economic one: what
percentage of the population shall be protected and at what price. In this context it
is important to note that the primary criticisms of the goals recommended in Issues
3 and 4 do not come from the organizations with the expertise in the area of the
effects of noise on man such as ASA and NIH but from the organizations primarily
and rightly concerned with the legal and economic consequences of establishing
maximum cumulative noise exposure limits for aircraft. The point is made in ATA's
position that the recommendations will affect many other industries such as manu-
facturing plants, railroads, highway systems, construction industry, etc., and that
the Task Group 3 recommendations should not have been made without their repre-
sentation and input. It is difficult to see what these organizations might have had to
contribute to the objectives of this Task Group which were primarily in the domain
of acoustics, psychological and physiological acoustics. As Appendix I shows,
considerable emphasis was placed on consistency of the Task Group's recommendations
with the noise'standards of the Federal Highway Administration and of HUD standards
of the Federal Highway Administration and of HUD and it is felt that the expertise
relevant to environmental/community noise was adequately represented among the
Task Group members.
H-4
-------
With respect to ATA1 s statement that neither the appendices nor the opinions of
the participants of the recent EPA-sponsored International Congress "On Noise As A
Public Health Problem," Dubrovnik, Yugoslavia support the findings and conclusions
of the Task Group 3 report, I must state that this does not agree with my interpre-
tation of the data and of the opinions of the international experts in this field. Scien-
tific discussions and differences of expert opinion on details should not be used as
arguments that there is no agreement among experts on what approximate noise
levels are incompatible with public health and welfare I The technical community
represented in the Task Group and those scientific technical organizations which
reviewed it supported basically the approach and the recommendations of the Task
Group. Several additional qualified organizations, which were invited to submit
position papers regarding the Task Group report and did not do so in writing, must
be assumed to have no major objections to the Task Group findings; in other words
the position papers received are apt to emphasize criticism of the report rather than
support.
There was one specific criticism regarding Issue 3 by the AOIC which claimed
that a recent HEW sponsored study on hearing of the inhabitants who lived around a
major airport was not included because the results would not support the conclusions
about expected hearing loss from environmental noises. The report was initially
left out because the results were inconclusive with respect to the 80 dB limit
recommended. I fully agree with the AOIC that this reference must be included in
the Task Group report and consequently a short discussion of the results of this
study is now included in Appendix B.
With respect to the recommendation that the Task Group report should be
identified as the Chairman's report not representing necessarily the opinions or
consensus of the Task Group, I have a mixed response. Certainly the Chairman had
the responsibility of assembling the report and making decisions in the deliberations
when decisions were needed. These responsibilities were not relinquished to some
majority of the Task Group members, which would have had no real validity since any
one was invited to join the Task Group activity. Nevertheless, the Task Group
meetings gave interested parties a chance to put forth their ideas and complaints.
New and novel ideas were thus possible. Appendix H and other documents in the Task
Group file document the members' participation. Likewise, ideas which were not
supported by members other than the Chairman were eliminated. The report could
never have been written without the devoted collaboration of the whole Task Group.
In summary, I think the report reflects the opinions and recommendations of the
Task Group as summarized by the Chairman; and the Preface indicates the degree
of consensus reached on the various issues. I think the final position papers collected
in this appendix and their evaluation in the above Table support this interpretation and
show that the report reflects indeed the majority opinion.
One final word about the complaints that not enough time was available for the
aircraft noise study and the Task Group report: I agree that the report is far from
perfect and could be improved with respect to details. On Issue 4 the above mentioned
economic study might have shown when and at what price the long-range goal of
Ldn < 60 dB could be realized or if indeed it might be feasible and realistic to lower
this goal to L
-------
Task Group can muster, will have to study this. However, I doubt if the basic conclu-
sions and recommendations of the Task Group report would have changed much if more
time had been available and I am confident that the report as submitted is a sound
and firm basis for long overdue action: to reduce environmental noise, and aircraft
noise in particular, to protect public health and welfare.
H-6
-------
SUMMARY OF SELECTED ISSUES RAISED BY THE POSITION PAPERS
ON T;iSK GROUP #3 REPORT
ISSUES
1. Shaw (ASA)
2. Janssen (EOF)
Cook (NIH)
'-, 4
Martin (AIAA)
5. Becker (ATA)
6. Reilly (AOCI)
7. Moore (LA
Airports)
8. Tyler (NOISE)
9. Blumenthal
(Boeing)
'dn
A-weigh ting
Immediate Goal
Ldn < 80 dB
Long-Range Goal
Ldn < 60 dB
Sat is factory
Satisfactory
Sat is f actory
Did Not Dis-
agree
Did Not Dis-
agree
S atisfactory
Did Not Dis-
agree
S at is factory
Not Satisfac-
tory, Mo re
Research Rod
Satis factory
Satisfactory
Satisfactory, Pre- Did Not Disagree
ferred D-weighting
Satisfactory, Pre- Satisfactory With
ferred D-weighting Qualifications
Did Not Disagree
Did Not Disagree
Available Data Not
Adequate To Support
Recommended Goal.
No Analysis Of
Economic Impact
Made.
S ame as 4 .
Satisfactory Same as 4.
Did Not Disagree Same as 4.
60 dB Satisfactory
50 dB Suggested
Suggested 55 dB
Suggested 55 to
60 dB
Available Data Not
Adequate To Support
Recommended Goal.
No Analysis Of
Economic Impact
Made.
Same as 4.
Same as 4
S ame as 4,
Satisfactory Did Not Disagree Satisfactory
Did Not Disagree No Economic Impact No Economic Impact
-------
ISSUES
Jdn
A-weigh ting
Immediate Goal
Ldn < 80 dB
Long-Range Goal
L < 60 dB
10. GAMA
Satisfactory Satisfactory
00
11. Ingard (INCE) Satisfactory Satisfactory
12. Gales (ASA) Satisfactory Satisfactory
13. Graves (HUD) Satisfactory Satisfactory
14. Bennin (City Satisfactory Satisfactory
of New York)
15. Dept. of
Commerce
Satisfactory Satisfactory
16. McPike Satisfactory Satisfactory
(Douglas Air-
craft Co .)
Satisfactory Pro-
vided Economic-
Impact Assessed
Satis factory
Satisfactory
Satisfactory With
Some Qualifications
Satisfactory
Did Not Disagree
Economic Impact
Must Be Assessed
With Respect To
Public Welfare
Satisfactory, But
Qualifi cations
Both Ways
Did Not Disagree
Satis factory
Satisfactory
Satisfactory
Satisfactory
Did Not Disagree
Economic Impact
Must Be Assessed
With Respect To
Public Welfare
Did Not Disagree
-------
ACOUSTICAL-SOCIETY-OF-AM ERICA
DIVISION Of PHYSICS
EDGAR A.G. SHAW '((((fisiMft NAT1ONAL RESEARCH COUNCIL Of CANADA
PRESIDENT ^\y^y/jj[ OHAWA,ONTARIO,CANADA KIAOSI
(613) 993-2840
June 30, 1973
Dr. Alvin F. Meyer, Jr.
Deputy Assistant Administrator
for Noise Control Programs
United States Environmental Protection Agency
Washington, D. C, 20^60
U. S. A.
Dear Dr. Meyer,
Further to my letter of June 29, I have now read
the report of Task Group 3 (Aircraft/Airport Noise Study) dated
1st June, 1973. It is, in my opinion, an excellent report for
which Dr. Henning von Gierke and the other members of the Group
deserve a. great deal of credit, particularly in view of the very
limited period of time they were given to complete their task.
The decision of the Group to adopt a simple
universal measure to characterize human noise exposure is, I be-
lieve, a wise one. Moreover, the day-night average sound level
Ldn based on average energy seems to be the optimum choice in
the light of the available scientific evidence and the practical
requirements. As indicated in Conclusion 8 (page III - k-k),
the secondary problems such as the pure tone components of noise
can be dealt with separately in emission control standards and
land use planning measures.
The key phrase "protection of the public health
and welfare" is clearly open to many interpretations. The
Task Group has very properly focussed its attention on the issues
for which a substantial measure of scientific consensus can be
found: the prevention of significant permanent noise induced
hearing loss, the limitation of annoyance, and the maintenance of
acceptable conditions for speech communication.
wTo protect the public against the risk of
permanent noise induced hearing loss, with adequate margin of
safety", the Task Group recommends that "a yearly outdoor day-night
average sound level of 80 dB should, as soon as possible, be
promulgated as the permissible limit with respect to health alone"
(page 111-^-5). This recommended limit is, of course, conservative
H-9
-------
ACOUSTICAL-SOCIETY-OF-AM ERICA
EDGAR A.G. SHAW
PRESIDENT
DIVISION OF PHYSICS
NATIONAL RESEARCH COUNCIL OF CANADA
OTTAWA, ONTARIO, CANADA KIAOSI
(613) 993-2840
Dr. Alvin F. Meyer,Jr.
Page 2.
June 30, 1973
by comparison with, the standards which have recently been set
for occupational noise exposure. At the same time it implies
acceptance of a snail but measurable hearing loss in the most
sensitive 10^ of the population over a 40 year period. The '
adoption of a limit 5 dB lower (i«e. L^n=75 dB) would nrovide
more complete protection for this sensitive minority. It
should also be noted that some recent scientific studies tend to
support a more cautious position.
In Recommendation 6 (p. III-4-6 ) a yearly
day-night average sound level of 60 dB is proposed as the long
range limit of the EPA for environmental noise quality in resi-
dential areas with respect to health and welfare. This limit,
when reached, will undoubtedly provide a large measure of relief
to the several millions of people who are at present subjected
to levels 10-20 dB higher than this limit. However, according
to Fig. III-IV-3. which is based on large scale surveys in the
U.S. and Britain, approximately 23^ of the population will remain
highly annoyed at Ldn=60 dB. The fraction highly annoyed could
be reduced to I8l'> by adopting a limit of 53 dB. In any case
L^n= 60dD hardly seems appropriate as a standard for residential
areas tolbe built in the future. So, it would seern appropriate
to adopt stronger language in the second part of Recommendation 6.
In fact, it might be desirable to recommend that L
-------
SPECIAL
ENVIRONMENTAL
DEFENSE (~Y-\ 1525 I8th
FUND x^X^x xam» STREET, N.W., WASHINGTON, D.C. 20035/202 833-1435
June 26, 1973
Mr. Alvln P. Meyer, Director
Office of Noise Abatement and Control
Environmental Protection Agency
1921 Jefferson Davis Hi^iway
Arlington, Virginia
Dear Mr. Meyer:
Ihe Environmental Defense Fund is pleased to have been given the
opportunity to participate in the drafting of the report of Task Group 3,
"Impact Characterization of Noise Including Implications of Identifying
and Achieving levels of Cumulative Noise Exposure." It was a pleasure
to work with so competent and effective a chairman as Dr. von Gierke,
whose straightforward direction and open mind account for the produc-
tivity of so diverse a representation. We sincerely hope for the
implementation of the Report's recommendations, although we wish to
voice a few reservations.
EOF fully supports the use of the A-weighted decibel as the basis
for the L, and the recommendation for future consideration of the
D-scale at such time as that has become standardized. We are in complete
agreement that, at this time, the A-scale is the only weighting scheme
which satisfies the criteria of meaningfulness, in terms of human
response, and monitoribility. However, it is also true that the A-scale
has certain deficiencies. The text of the Report takes account of these
deficiencies, but it is our opinion that they are not adequately spelled
out in the "Conclusions and Recommendations" section at the end of the
Report. Conclusion No. 8 is addressed to pure-tone components and the
lack of penalty for these in the A-weighting system, but there is no
mention at this point of either the A-scale's leniency with regard to
low frequencies, or of its Inadequacy with regard to impulsive noise.
Because of the aversiveness of both impulsive noises and of low-
frequency emissions from certain sources, such as trucks, it is our
feeling that this point needs to be mentioned in the conclusions. It
is further suggested that the certification procedures referred to
in the text for sources Inadequately described by use of the A-scale
be made explicit in the form of a recommendation.
A further, and more substantive, comment relates to the stated goal
of 60 Lp... We suggest that 60 L~, be an intermediate goal, and that
55 LT»I is a more suitable long range goal. We submit that a solution
OFFICES IN: EAST SETAUKET, NY (MAIN OFFICE); NEW YORK CITY (PROGRAM SUPPORT OFFICE); WASHINGTON, DC; BERKELEY-. CALIF.
This piper la recycled to protect the environment.
H-ll
-------
Mr. Alvin F. Meyer -2- June 26, 1973
which leaves 23% of the noise-exposed population highly annoyed (which
would be the case at a level of 60 L ) is inadequate. The Report states
in the section on "General Health Efiects of Noise" that "it does
not appear that anything would be gained by setting the goal for day/night
average sound level lower than 60 db." Fig. III-3-2, on the other hand,
indicates that attainment of a 55 L^ goal would result in a reduction
of the numbers of those highly annoyed by about 5%, which is hardly
; -gligible. It appears that unduly heavy reliance may have been placed
u^on the seemingly low complaint figure of 2%. However, it must be
pointed out that complaint figures, while convenient, are inadequate
descriptors of the effects of noise on people. Conplaint rates are
known to be correlated with such irrelevant factors as socio-economic
status, and it is quite conceivable that, as the public consciousness
about noise rises, complaint rates may rise appreciably. As to the question
of economic feasibility, the report declines to indicate a time schedule
for implementation, and a time schedule for attainment of an L^ of 55
may as easily be based on the detailed economic and technological feasibil-
ity studies referred to in Recommendation No. 7.
Of further concern is the problem of environmental degradation and
the probability that the goal, as stated, may constitute a "license to
pollute." We feel quite strongly that there is the need for a specific
recommendation in the report with regard to this matter, particularly
in light of EPA's mandate, under Sec. 5(a)(2) of the Act, to state by
next October 2? "the levels of environmental noise...requisite to protect
the public health and welfare with an adequate margin of safety." (Emphasis
added.) The L^ goal does not provide this margin, and, therefore, where
levels of noise exist which are sufficiently low in these terms, they
must not be allowed to rise to a point at which this margin no longer
exists.
It has been argued by seme of the report's detractors that science
simply does not know precisely what the effects of noise on human health
are and that therefore no permissible dose levels may be recommended at
this time. It is the position of the Environmental Defense Fund, as a
public law and science organization, that in an area such as this one,
where enough evidence has accumulated that seme conclusions may be drawn,
it is the scientist's responsibility to urge action on the basis of this
information. To put off a decision for the years required to eliminate
doubts from 'everyone1§ mind constitutes an immoral and irresponsible
decision not to act in the public interest. This Task Group Report
indicates that the time has finally come when scientists specializing
in noise effects will use their knowledge for the protection of the
public. We sincerely hope that the recommendations of the Task Group
will be effectively acted upon and that relief may finally be gained
for the noise-exposed segments of our population. Similarly, we hcpe
that modifications in the L^ goals will be made as indicated by future
research.
Sincerely yours,
Raelyn Janssen
cc: Dr. Henning von Gierke Staff Scientist H-12
-------
DEPARTMENT OF HEALTH, EDUCATION. AND WELFARE
PUBLIC HEALTH SERVICE
NATIONAL INSTITUTES OF HEALTH
NATIONAL INSTITUTE OF
ENVIRONMENTAL HEALTH SCIENCES
P.O. BOX 12233
June 28, 1973 RESEARCH TRIANGLE PARK. N.C. 27709
Dr. H. E. von Gierke
Chairman, Task Group 3
Aircraft/Airport Noise Impact Characterization
6570 ANRL/BB
Wright Patterson AFB, Ohio 45433
Dear Sir:
It has been a pleasure to serve on Task Group 3 Airport/Aircraft
Noise Impact Characterization analysis.
The problems for which the task group was charged with finding
practical solutions are very complex, and many areas admit of dis-
agreement between reasonable men, but one thing was clear: reaching
a consensus and moving forward on the basis of the best information
is so urgent that we must not let less than perfect data or disagree-
ment over part(s) block essential agreement on the whole.
The consequential conclusions of task group 3, which I share, are ac
follows: Environmental or community noise exposure must be viewed
and measured in terms of what reaches an individual's ear, from all
sources, summed over a reasonable time period; with a physical descrip-
tor which is simple, economical, practical, applicable to all kinds of
noise intrusions, and accurate within the requirements of community
noise.
It quickly became apparent that the extraordinary diversity and com-
plexity of community noise precluded its being completely characterized
(in terms of human adverse reaction) by methodology which met the
tests of simplicity, practicality, and economic feasibility. It is to
the task group's credit that it formally recognized that the simple
frequency weighting (dBA), energy summing methodology chosen cannot
well account for human physiological/psychological response to pure
tone components, pulsations, impulses and other deviations from fairly
broad, uniform sounds, and as a result, would have to be complemented
by more sophisticated source emission characterization methodologies
for major contributors to community noise. This methodology already
exists for aircraft. Aircraft noise because of its mid-frequency and
pure tone sound emission characteristics, has been found to be best
related to human adverse response when described by the E PNdB methodo-
H-13
-------
Dr. H. E. von Gierke Page 2
logy now codified in FAR part 36. (This E PNdB methodology attempts
to account for the fact that growth of loudness or adverse reaction
is a function of bandwidth as well as the frequency response of the
ear and presence or absence of pure tones.) It is the writer's
feeling that the degree of success of this dBA community noise
descriptor hinges upon the rapid establishment by EPA of more accurate
source characterization methods for the other major sources of
community noise, specifically but not limited to, truck noise.
A second value judgment of extreme importance made by the task force
concerns adoption of the rule of 3 dB for doubling of exposure time
(equal energy) to handle the intensity-duration tradeoff. In
defense of this rule, proponents pointed out that equal energy is
conservative for hearing loss. On the negative side, it appears to
put "minimum distance" between exposure lengths relative to annoyance,
i.e. 80 dBA for 8 hours would be considered equal to 83 for 4 hours,
and 0 for the remaining 4. Given a choice, the great majority of
people would opt for the 83 dBA, 4 hour exposure. However, community
noise except in rare instances has a fairly continuous character,
and no one had any data from the real world saying that a 5dB or 6 dB
magnitude tradeoff per doubling of time was any better than 3 dB.
Neither was there any data which definitely indicated anything better
than a 10 dB nightime tradeoff. So, in general, I fully support the
approach of the task force as expressed in the first draft, along with
the goal of an L^n of 55-60 dBA, provided EPA follows through with
developing and implementing specific source emission descriptors for
major sources whose emission characteristics deviate (by containing
strong pure tones, pulsations, impulses, etc.) from fairly steady
state, broad spectrum character.
Again, the statistics, (page III 3-14), indicating that at an Ldn of
60 dBA, 23% of persons find themselves "highly annoyed" with the noise,
are disturbing. If these prove to be credible statistics, reflecting
real conditions, e.g. real rather than "displaced" annoyance, then the
long range goal of the EPA may have to be revised downward.
In connection with these recommended levels, the draft document
contains no mention of non degradation of present environmental
noise levels. Without attention to this point in the report, the
layman might conclude that the 80 dBA Ldn to be recommended as an
initial limit was "sanctioned" by EPA as not being detrimental to
health and welfare, when in fact it was chosen to avoid widespread
economic dislocations relative to existing sources and should not be
considered acceptable as a limit to which new sources might be
permitted to raise community noise levels.
H-14
-------
Dr. H. E. von Gierke Page 3
At the combined task force meeting on June 2122,some speakers from
other task forces made statements to the effect that they interpreted
the task group 3 report as saying that health effects from chronic
noise exposure did not occur below levels sufficient to cause hearing
loss. Upon re-reading the relevant pages (III 3-14, III 3-15) care-
fully, I find that the report does now appear to embrace this view,
but gives little attention to an issue of such significance. It quotes
and accepts the judgment of the author of a recent critical review
who says that, "if noise control sufficient to protect persons from
ear damage and hearing loss were instituted, then it is highly unlikely
that the noises of lower level and duration resulting from this effort
could directly induce non-auditory disease." I would point out that
scientific opinion is by no means unanimous on the issue of non-audi-
tor}' effects at this level and other authors could have been found
(or quoted) who would be considerably more cautious in assessing the
potential for long term deleterious health effects. With respect to
noise induced sleep loss, which is one such non-auditory effect occuring
in noise environments incapable of producing hearing loss, it is clear
that the medical profession certainly thinks that chronic loss of sleep
has deleterious health effects, judging from the number of sleeping
pills prescribed. Furthermore, to exonerate noise as a health affe-N.or
en the bacis on rion-prodactiua of classic disease symptoms ±s begging
the issue by oversimplification. No one has suggested that noise directly
(immediately) causes certain diseases. What has been suggested, is
that continuing noise exposure may be capable of producing a chronic
stress syndrome in some individuals, with consequent elevated endocrine
levels leading to deteriorative changes occuring over time. And, for
what it's worth, the results of animal experiments conclusively demon-
strate the presence of major non-auditory effects. One point is clear,
however: more well controlled research is needed to clearly delineate
the potential of chronic noise exposure for inducing long range deterior-
ative health effects.
In the spirit of telling it like it is, we fully realize and are in
accord with the fact that the EPA must make some very difficult cost-
benefit decisions which must withstand testing in the political arena.
We submit that it would be untenable,however, to say or imply, as
part of the justification for the level chosen, that no health effects
occur below 80 L^ or some figure or that some such level marks
the demarcation line between "health effects" and "welfare effects."
Sincerely,
Reginald 0. Cook
National Institute of Environmental
Health Sciences
H-15
-------
AEROSPACE INDUSTRIES ASSOCIATION OF AMERICA. INC.
1 722 ZC. SALES STRFET. N W W ASH I NGTOM. O C.2GO36TEL 347-2315
July 2, 1973
Dr. Alvin F. Meyer
Deputy Assistant Administrator for
Noise Control Program
Environmental Protection Agency
1921 Jefferson Davis Highway
Room 1115
Arlington, Virginia 20460
Dear Dr. Meyer:
At the invitation of the Administrator, Environmental Protection
Agency, several AIA member companies participated in your Aircraft/
Airport Noise Study. A study task force, divided into six study
groups, has assisted in developing respective parts of the report
required by the. Noise Control Act of 1972. Because of the pace
of task group activities and broad scope of information and data
being assembled, it was not possible for AIA to develop and submit
positions as the study progressed.
We are deeply concerned over the conduct of the study and
desire to provide the following comments on this matter:
a. The total subject of aircraft noise control, including
standards, retrofit or phaseout of existing aircraft,
cumulative noise exposure, operating procedures and
definition of health and welfare is exceedingly complex
and involved. We are concerned that the five month
period available did not allow sufficient time for EPA
to assemble a team, let contracts, and accomplish the
work necessary to complete the study in a entirely
satisfactory manner. Furthermore, this short time made
it impossible for the task group members to adequately
analyze the findings of the contractors or comment
on the work to date in any detail.
b. Because of the diverse backgrounds, expertise and
interests of the task group members, little attempt
was made to determine consensus or majority opinions on
the multitude of questions discussed in the meetings.
Many of the conclusions and recommendations developed
by Task Group Chairmen vere in fact not even covered in
the meetings. Consequently. <:he final reports should
».vt be represented as the conclusions and recommendations
of the. task groups. They arc, more realistically, the
,-,;-;ir.'. ---ns and individual views of the *J>.sk Gro"p Chairmen
H-16
-------
Dr. Alvin F. Kftyer -?.- July 2, 1973
which in some impoi '''; ....'.istances do not reflect the
arguments and facts r.e.if ,:d by the members.
..» ***, r i *
The A1A supports efuo -. to review the existing noise
standards for ncv/ air' raft designs and to strengthen
them. The successful intr-.-.luction of resulting quieter
aircraft into the fleet is critically dependent on
Federal action to insure t: at these aircraft once
certificated a.- complying -. 1th the applicable standards
shall have the right to op..rate at all airports, where
they meet airworthiness requirements. It is essential
that airport operators be preempted from prescribing
restrictions which would prevent such certificated
fli.roraft from operating at their airports. The
necessity for federal preemptions does not conflict
with the use of noise abatement operating procedures.
However, it is essential that the operational
procedures and required aircraft equipment be FAA
prescribed for reasons of safety of operation, pilot
training and equipment interchangeability. Any
other course which permits individual airport
authorities to specify unique requirements will
lead to chaos and will be counterproductive to
the intent of Public Law 92-574.
In general, we find that the cost analysis approach
taken by EPA was inadequate. For example, the cost
analysis on curfews would suggest that night time
curfews offer a very efficient means of reducing
noise exposure areas on per dollar cost basis.
In fact, the adverse economic impact resulting from
disruption to overseas travel and from aircraft being
other than where needed for the following day's
flights would be severe and was not properly considered.
Another example is in the. case of land use studies
where more factual data is needed in place of
oversimplified extrapolations. We are convinced
thai the economic analyses uiusu bo completely re-
examined before any meaningful conclusions can be
drawn.
While AIA is not in a position to disagree with the
general approach taken to rate noise exposure using
the dM unit, we strongly question the selection of
the specific values of 80 for hearing damage and 60
as the ultimotu.goal for annoyance or disturbance
criteria in the Ldn scale. The data presented does
not adequately substantiate the selection of these
Jewels. The implication and impact of these limits
is far reaching. Such limits require substantiation
prior to their selection..
H-17
-------
Dr. Alvin F. Meyer -3- July 2, 1973
f. The FAA noise regulatory actions recommended by the
Task Group Chairmen contair. a number of elements with
which A1A is not in agreem it. These disagreements
will be discussed at the time issue of subsequent
regulatory notices.
The AIA recognizes the extent of the noise problem and the
need for progress in alleviating itr. impact on the environment.
We agree that regulations and procecures relating to operations
and compatible land use are necessary to assist in reducing noise
exposure. We also agi.ee with the need for continued research to
reduce noise at the source and provide operating procedures to
reduce noise exposure for airport neighbors. We concur with the
need to provide financing for research, equipment development,
implementation of noise control measures, and land acquisition.
In closing, we do want to commend the EPA Task Group Chairmen
for their diligent efforts under difficult circumstances. We
urge your consideration of our concerns discussed above.
This letter revises AIA letter of May 25, 1973 to you.
It is submitted in request to your appeal at the EPA hearings
on June 20, 1973 at the Department of Commerce Auditorium,
Washington, D. C. for all previous submittals made to EPA on
the study subject be reviewed and revised not later than
July 2, 1973. As reflected in our statement at the hearing on
June 20, 1973, it is requested that this statement be included
in the record of all study groups.
Very truly yours,
AEROSPACE TECHNICAL COUNCIL
Martin
Associate Director
Civil Aircraft Technical Requirements
GIMissf
cc: John Schcttino - EPA
EPA Task Group Chairmen (6)
H-18
-------
Air Transport Association ££Zi OF AMERICA
1709 New York Avenue, N.W.
Washington, D. C. 20006
Phone (202) 872-4000
July 2, 1973
Mr. John Schettino
Director - Aircraft/Airport Noise Study
Environmental Protection Agency
Crystal Mall Building No. 2, Rm. 1107
1921 Jefferson Davis Highway
Arlington, Virginia
Dear Mr. Schettino:
In line with Dr. Meyer's announcement at the EPA Conference
on June 21 and 22, regarding the draft reports of the six Task Groups
established to make the study required under Section 7(a) of the Noise
Control Act of 1972, I hereby am forwarding my comments on the draft
report of EPA Task Group 3. I request that this letter, and the attach-
ments thereto, be included in the final report of the chairman of Task
Group 3. My previous ieilers uf Ma_y 10 aad Juuc 1 to Dr. voi.1 Ciei'ke
on the earlier draft can be disregarded for the purposes of the final
report, as I recognize there have been a substantial number of minor
as well as major changes in the second draft.
The comments contained in this letter, and the attachments to
it, refer to the "Draft Report on Impact Characterization of Noise
Including Implications of Identifying and Achieving Levels of Cumulative
Noise Exposure, " dated 1 June 1973.
I recommend that your final report indicate that this is the report
of you, as chairman, and not a report of the Task Group, or even a
consensus of the Task Group as there is still obvious large disagree-
ments as to the contents of much of the report. In addition, particularly
during the last committee meeting on May 11 it developed that there was
little, if any, scientific support for the recommendations and conclusions
of the draft report as much of ihe justifications cited throughout the re-
port is based on hypotheses and theories, from which time has not
permitted conclusions to be drawn. For example, I do not see agreement,
supported by facts, regarding the cumulative noise exposure formula set
forth in the report, or that an Lcin of 80 dBA is the appropriate limit to
be prescribed. Certainly the Appendices A through D to the report do
H-19
-------
- 2 -
not support the conclusions. In addition, the recent International
Congress on Noise as a Public Health Problem held in Dubrovnik,
Yugoslavia verifies to me this same point, i. e. , there is no agree-
ment on the basis for the findings in the report. In other words,
and it was pointed out time and time again at the Dubrovnik meeting,
(a) there are great differences in opinion as to how cumulative noise
exposure should be measured, if it should be used at all as a means
of determining the effects of noise on the public health and welfare,
(b) there is no conclusive knowledge as to the effect of noise exposure
on humans, and (c) no agreement as to the actual level of peak noise
or continuous noise which may or may not affect the public health
and welfare. There is no agreement even as to what is "normal
hearing, " much less what hearing loss is normal, as opposed to
induced hearing loss. I gather that the experts in the field, such
as yourself, have been trying for 15 years or more to arrive at an
agreement on cumulative noise exposure without success, and just
because the U. S. Congress says that this must be done within a
year's time, we must have such an agreed on formula. Whether
that formula, or the noise exposure limits recommended, is possible
or correct seems to be of secondary or little importance, notwith-
standing the effect such limits would have on the industry of the
country and the "health and welfare" of the nation.
Following along with the thought expressed in the previous
paragraph, I specifically cannot see how we can establish firm noise
level limits for "health and welfare" purposes when the great majority
of studies referred to as the basis for the determination reached are
full of assumptions, expectations, predictions, small statistical basis,
approximations, estimations, probabilities, conceptions, proposals,
etc. This too was verified for me by the presentations at Dubrovnik.
As Mr. Robert D. Moran, Chairman of the U. S. Occupational Safety
and Health Review Commission indicated at Dubrovnik, noise theories
and hypotheses based on assumptions, etc. , cannot be the basis for
rules or regulations and enforcement proceedings that are expected
to stand up before challenges in the courts. You may recall that,
generally speaking, Mr. R. F. Higginson of the U.K. supported Mr.
Moran's viewpoint. Enclosed is a copy of the paper Mr. Moran sub-
mitted at the Dubrovnik Conference. (Attachment I). It is requested
that it be included in your final report.
I think it is necessary that whatever noise measurement standard
is used, or whatever cumulative noise exposure formula is determined
to be appropriate, must be workable for regulate 17 and enforcement
purposes. The proposals set forth in the draft report do not fit these
H-20
-------
- 3 -
requirements. As one who has been associated with federal regulations
in the aircraft safety field for a number of years, I see no possible way
by which the recommendations in the draft report can be reflected in
regulations or enforced in an environment where many noise sources
(both peak and continuous) are creating the total noise exposure problem.
Many industrial, residential, transportation, recreational, etc. , noise
sources would be governed by the proposal set forth in the draft report,
because if the formula and the levels included in this report are to be
effective they would have to apply to all noise sources. In many cases
no single noise source would be prominent enough to create the noise
exposure to be regulated.
This is particularly true when one takes into consideration that
the report recommends that the noise exposure dose is to be related
to each individual. Most individuals are moving from a residence
noise level, via a transportation system (noisy), to a workday noise
environment, and back to his residential noise level by, again, a noisy
means of transportation. It is impossible to control the noise dosage
without controlling (a) the kind of work the individual will do as related
to the noise levels to which he is exposed, (b) how, and how long, he
would be exposed to transportation noise while to and from work, (c)
the noise exposure at his residence and (d) the noise level associated
with his recreation activities.
Associated with this last comment must be the fact that EPA Task
Group 3 is, in effect, establishing cumulative noise exposure levels with
respect to the health and welfare of the public from all the noise sources
of many industries, such as manufacturing plants (of all kinds), the
railroads, the highway system, the automobile industry, the building
construction industry, etc. , and yet no representatives of these various
industries and systems have been present in the discussions of the
working group. In fact, I doubt that the various industries who will be
concerned with Task Group 3's report are aware that the task group is
working in an area that will radically affect the economic and technical
well-being of their industry, and the nation at large.
In each of the five meetings of Task Group 3, the point has been
brought up, in one form or another, that it was not possible in the time
available to analyze the overall economic impact of reducing most
human noise exposures in the U.S. to the maximum permissible levels
indicated in the report. The report points'-'out on page III-3-1 that the
decision on maximum permissible noise levels involves "value judge-
ments in the political, social, ethical and economic domain, beyond
the responsibility of the Task Group. " (Underlining supplied.) I feel
it is quite wrong to attempt to prescribe noise level exposure limitations
which will have great economic, technical and legal effect on the well-
being of the industries throughout the nation and thus the well-being of
H-21
-------
- 4 -
the general public without knowing within a fair degree of certainty
what the economic effects of such proposed exposure limits will be.
I can assure you that the recommendations contained in the draft
report, if they are adopted, could and will have disastrous effects
on the aviation industry and the air transportation of the U. S.
One other general point, the draft report uses the term public
health and welfare, to mean the health and welfare of people living
near a noisy facility such as an airport, railway, highway interchange,
manufacturing plant, etc. The point was developed by several members
of the Task Group, including myself, that "public health and welfare"
refers not only to such people. The health and welfare of the entire
nation and the whole community served by an airport, a railway, a
highway, etc. should be included by EPA in determining "what is
necessary to protect the public health and welfare. " You will recall
that it was agreed that the Task Group could not possibly study the
complete welfare question, or for that matter the public health question,
adequately on the broad base that is necessary under the provisions of
Section 6ll(c)(l) of the Federal Aviation Act of 1958, as amended by the
Noise Control Act of 1972. There are several places throughout the
paper where this omission is not recognized. In addition, EPA cannot
disregard the need of transportation, be it airplane, bus, train, etc.
Oi" tuc Liecu for tut; COiiSii'UCtlOii Oi bUIxuiugS, Su'Owa.^'D, luguwcty b,
(during which excessive noise is produced), all of which is necessary
for the public welfare and health of the whole population and the nation.
We feel that it is very necessary that this report include the fact that
the kind of study needed and referred to above, could not be accomplished
because of lack of time.
I hope these points will be of some assistance to you. 'My detailed
comments on the draft report dated June 1, 1973 are included as
Attachment II.
Sincerely,
William B. Becker
Asst. Vice President - Operations
Attachments
Copy to:
Dr. H. E. von Gierke - EPA Task Group 3 Chairman
Dr. A. F. Meyer, Jr. - EPA
WBBrlbh
H-22
-------
The paper referenced by Mr. Becker as Attachment I,
"Some Practical Aspects of Controlling Excessive
Noise by Government Regulation", by Robert 0. Moran,
was not included in this report, but is being
published in the proceedings of the EPA sponsored
International Conference on "Public Health Aspects
of Noise at Dubrovnik, Yugoslavia, May 1973.
H-23
-------
Attachment II.
July 2, 1973
Detailed Comments on Draft Report on "Impact Characterization of Noise
Including Implications of Identifying and Achieving Levels of Cumulative
Noise Exposure" - June 1, 1973 - EPA Task Group 3.
1. Page III-v, paragraph number 3 at the top of the page. I wish
to point out as I did at the EPA Conference on June 21, 1973,
that neither Task Group 3, or any of the other five Task
Groups, conducting the studies determined "the implications of
issuing Federal regulations establishing a standard method for
characterizing the noise from aircraft/airport operations and
of specifying maximum permissible levels for the protection
of the public health and welfare. "
2. Page III-v, first paragraph under APPROACH. As pointed out
in my covering letter, this report in its final form should be
that of the chairman of Task Group 3, as it does not represent
conclusions and recommendations of the Task Group, or
consensus of the members thereof.
3. Page III-v, paragraph number 2 at the bottom of the page. It is
absolutely impossible to regulate a noise exposure dose for
individuals and such a rule enforced. For example, the level
received during an eight-hour working day by a foundry worker
is far from that received by a salesman in a clothing store. In
addition, the noise to which each is exposed during transportation
to and from work will vary widely, even though their homes were
next door to each other in a neighborhood where the noise level
is acceptable. Unless we are to put restrictions on (a) the kind
of work an individual will do, as related to the'noise levels to
which he is exposed, and (b) at the same time govern how he is
transported to and from work, as well as (c) where he lives;
there is simply no way to follow through with the concept outlined
in this paragraph.
4, Page Ill-vi, paragraph 3. Same comment as in comment 3 above.
5. Page Ill-vi, paragraph 4. 1 certainly cannot agree that the
urgency to characterize a cumulative noise exposure is such that
substantiating research data and refinement should not be waited
for. Premature cumulative measuring methods, and the
establishing of unrealistic cumulative noise levels, will have a
devastating effect on industry and the nation.
H-24
-------
-2-
6. Page Ill-vi, paragraph 5. Strike the phrase "and need not" in
the first line. We feel that the cumulative environmental noise
exposure should be taken into account, even though practically
we must recognize that it cannot be done. Taking these three
words out will not reduce the effectiveness of the paragraph.
With respect to the second and third sentences of this paragraph,
I feel that the cumulative noise exposure should take into account
one-time noise events, high instantaneous peak values, etc. I
know that it makes it more difficult to establish an acceptable
cumulative noise exposure standard, but we cannot disregard
these noises, and the regulation of the noise source will not
otherwise be effective many times. As to the rest of the para-
graph, I feel that there should be one measurement standard
for the purpose of rulemaking, and enforcement, etc. There
can and should be only one unit of measurement for all noise
sources, be it aircraft noise, chain-saws, air-conditioners, etc.
At least in the airline industry we cannot be regulated for
emission purposes by one measurement unit and have operating
regulations and enforcement thereof under another unit.
Regarding the last two paragraphs of Paragraph 5, I don't think
either is a true statement. T don't recall any consensus of agree-
ment on the approach and contents of Sections II or III.
7. Page III-vii. Last paragraph on the page. I do not concur that
the overall economic impact of achieving the noise levels
prescribed in the report was gone into in any depth whatsoever.
Nor do the reportsof Task Groups 1,2,4 and 5 provide any
clues as to the economic impact of the cumulative noise level
methodology and the levels prescribed, particularly with respect
to aviation, and even more particularly with respect to other
noise sources. The last sentence starting on the bottom of this
page indicates that a vote was taken as to the need for a goal for
a maximum permissible exposure. There was no such vote, nor
as far as I can recall agreement, particularly with respect to
the Ldn levels prescribed further on in the report.
8. Page III-l-l, first paragraph. As noted in comment 1 above,
the "implications of identifying and achieving levels of cumulative
noise exposure around airports" are^not provided by this report
or the other five Task Group Reports.
9. Page III-l-l, paragraph 1. Do not believe that as of this point in
time there is sufficient information available to provide fhe
correlation needed.
H-25
-------
-3-
10. Page III-l-l, paragraph 5. Suggest that this sentence be changed
to read as follows: "The measure for airport noise should be the
same as that currently used for noise from other sources. "
Again, I point out the necessity to use one unit of noise measure-
ment for all purposes, i. e. , noise source regulation, operating
regulations, cumulative noise measurement, enforcement, etc.
There should be no special application measure for aviation
noise regulation or enforcement.
11. Page III-J-1, paragraph 6. Considering all sources of the various
noises be taken into consideration, predictability measurement
of cumulative noise exposure is impossible because of the lack of
knowledge of all noise causes and sources. This is particularly
true insofar as aircraft engine noise is concerned. Very frankly
we know comparatively little of the "physical events producing
the noise" from aircraft engines. Aviation noise experts are
just beginning a learning curve.
12. PageIII-1-3, second full paragraph, last sentence. As mentioned
earlier dBA should be used from an engineering noise control
aspect. dBA should be used across the board.
13. PageIII-1-4, third full paragraph. As stated earlier, FAR Part
36 which regulates noise emissions from aircraft engines should
also use dBA.
14. Page III-1-6. Under the heading AVERAGE SOUND Level, last
sentence, it is suggested that the daytime be defined as 0701 to
2300, and nighttime be defined as 2301 to 0700.
15, Page III-1-7 and III-1-8. Notwithstanding the.explanation set forth
in the appendices, the 10 db differences between night and day
certainly hasn't been proven scientifically, or accepted inter-
nationally. In other words, to my unscientific mind, the 10 db
penalty urged for application to the nighttime period is really
based on opinion, not proven, and seems to be continually pro-
posed on the basis that "if we say it often enough, it will become
fact. "
16. Page III-1-9. First five lines at th# top of the page and the
following paragraph. After the word "indoors" where it appears
three times in these two paragraphs, insert the phrase "and in
vehicles" and at the end of the fifth line at the top of the page add
H-26
-------
-4-
the phrase "and vehicles. " The point is, much time is spent by
individuals throughout the United States inside vehicles such as
buses, trains, automobiles, etc. going to and from their work
and recreation, and noise is attenuated by these vehicles.
17. Page III- 1-9. First full paragraph. Do not concur -with the con-
clusion set forth in this paragraph, although it is an easy way
around a difficult problem. We believe the application of these
considerations should be included in L x>^ » «* f*
l l^OO CIA 1*J CilV-' I.C/UX tO.
Approximations and assumptions cannot be the viable basis for
the kinds of recommendations and conclusions set forth in
Section V of this report.
19. Page III-1-9, third full paragraph, and chart at bottom of page.
The word "approximately" appears in the paragraph as well as
the abbreviated form in the chart. Also the word "typical"
appears in the sentence immediately preceding the chart. The
use of these words heightens the concern expressed in item 18
above.
20. Page III-1-10, paragraph 2. The sentence here contains a double
negative and makes the thought which I believe to be expressed in
the sentence quite erroneous. In addition, we do not believe the
factors set forth here, or in paragraph 1, immediately preceding
should be used by local jurisdications. Decisions of this nature
have to be done on a national basis'^/ we are to have a safe and
effective national air transportation system.
H-27
-------
-5-
21. Page III-1-10, last paragraph. Again the 10 decibel difference
between daytime and nighttime is challenged and we recommend
that "2200" in both places where it appears in the second sentence
be changed to "2300"
22. Page III-1-11. Large paragraph in the middle of the page. I
gather from several of the rather heated discussions at Dubrovnik
that there is far from complete agreement on the method outlines
here for measuring the accumulation of sound as it does not
recognize appropriately temporary peak noises and the recovery
from the effect of such peak noises on man. I gather, and I am
not really qualified to discuss this point at all, that there is still
much disagreement among experts in the field on the conclusions
set forth in this paragraph.
23. Page III-2-1. Second full paragraph. At the end of this paragraph
the point is made that there are "more elaborate computerized
monitoring systems now coming in use at major airports. " Though
I am not too familiar with these systems, what knowledge I do have
with respect to one system, i. e. , that being installed at Los
Angeles International Airport (and it is not yet usable after nearly
two year? of ^valuation) does not record noise exposure from all
sources. Because of the purpose of the LAX monitoring system,
it only records noise above a certain specified level which is
pre-set in the instrumentation. In other words, the LAX system
does not record total cumulative levels from all sources.
24. Page III-2-4. Item 3. The phrase "aircraft acceleration effects"
is not understood by me. Thus, it needs further explanation in
the text.
25. Page III-2-4. Paragraph 6. Strike the phrase "busy-day" and
insert the phrase "average-day. " Why should the worst day be
used in computing aircraft noise exposure.
26. Page III-2-4. Add the following paragraphs as 9, 10, 11, 12 and
13:
"9. Wind-rose data for runway involved.
"10. Aircraft operating weights on takeoff.
"11. From aircraft operator - the variations in flap, power
setting and airspeed used in takeoff and landing.
H-28
-------
-6-
"12. Runway gradient and runway surface, as related to aircraft
model acceleration.
"13. Terrain (rise or fall) from airport surface level. "
27. Page III-2-4. Second last line on page. Change the word
"Differences" to "Major differences".
28. Page III-2-5. Eighth line from the top. I believe the phrase " +
1 dB" will be quarrel-ed with by experts in the field. It is
suggested that the following phrase be substituted, "a few dB"
29. Page III-2-5. Paragraph in the middle of the page. I have
difficulty with this paragraph because it deals with measuring Ldn
levels and indicates that such measurements are preferable to
predicted values. However, the first paragraph of this section
indicates that we are only talking about predicted values as
opposed to measured values. In other words, this paragraph
does not "track" with the first paragraph in this section appearing
at bottom of Page III-2-2.
30. Page III-2-6. First paragraph after the heading, add after the
phrase "motor vehicle traffic", the following "factories, con-
struction, etc. "
31. Page III-2-6. First sentence last paragraph is not necessarily
true. There are many cases where though an airport noise
situation is "of interest", the dominant noise near the airport is
not that of aircraft. Measurement of such noises as in the
Georgetown area near Washington National Airport has proven
this to be a fact. There are other cases as well.
32. Page III-3-1. First paragraph. The second sentence indicates
that this section of the report is based on recent surveys of
"scientific data" that will support EPA's criteria document.
The scientific data that is alleged to support EPA's criteria
cannot be found in the pages following in Section III-3. Several
so-called studies which follow in Section III-3, are not based on
factual provable information and are full of assumptions,
expectations, predictions, small statistical basis, approximations,
estimates, probabilities, hypothesis, and theories. The infor-
mation is not specific enough to be interpretable for the purpose
at arriving at a maximum permissible average level with respect
to cumulative environmental noise exposure.
H-29
-------
-7-
33. Page III-3-1. Second paragraph. After the word "responsibility"
in the fourth line, add the phrase "and capability". In the last
sentence of this paragraph it is indicated that the options available
for setting the maximum permissible average sound level are
restricted to a range of not more than 20 db, no matter how to
challenge to avoid significant effects on health and welfare is
interpreted. As stated in comment 32 above, the conclusion
reached here is far from provable.
34. Page III-3-1. In the sentence starting at the bottom of this page
and continuing on to the next, it is concluded that annoyance due
to noise and interference with speech communication, should be
interpreted as interference of the noise environment of public
welfare according to the intent of the Noise Control Act. I
assume this is a conclusion of the chairman, as it is not
supported in the draft report. In addition I suggest places the
definition of "health"set forth by the World Health Organization
in the paper for ready reference.
35 PageIII-3-2. First full paragraph. The phrase "reasonable to
require" in the fourth line when associated with the phrase "these
assumptions" in the third last line indicates the unscientific
approach being used here. In addition, the second criteria
referred to, i. e. , "Economically feasible" is not supported by
the study - see the second paragraph on the preceding page, i. e. ,
III-3-1. In addition, the statement in paragraph number 2 which
states "These levels can be enforced by relatively simple environ-
mental noise monitoring systems" is not true. The Los Angeles
noise monitoring system has been worked on for two years and
it still is not functioning properly.
36. Page III-3-3. The sentence at the top of the page, and which
commences on the preceding page, is one that contains the type of
conclusion which we have commented on before. See comments
6, 10, 12 and 13.
37. Page III-3-3. First full paragraph. "Local authorities" should
not have this authority, if we are to have a safe and efficient
national air transportation system. Add to the end of the sentence
ending this paragraph the following, "construction, manufacturing,
etc. "
38. Page III-3-3, Paragraph under "HEARING LOSS". The word
"potential" as used here certainly indicates there has not been any
proven permanent hearing loss documentation.
H-30
-------
-8-
39. Page III-3-3. The word "assume" in the third line of the last
paragraph is prominent and the word "generally" in the last line
also is prominent.
40. Page III-3-4. Second full paragraph. No where do I see the con-
clusions reached and set forth in this paragraph, supported or
justified.
A similar comment is made with respect to the paragraph under
"INDIRECT EFFECT". Again, note the word "assuming" in the
second sentence of this paragraph.
41. Page III-3-5. In the chart at the top of the page the "double asterisk"
note indicates that one should "add 5 dB to the average sound level
for intermittent noise such as that produced by aircraft operations. "
Who says so? Where is the justification?
42. Page III-3-5. Bottom of the page. The conclusion indicated by
this paragraph does not relate properly or agree at all, as 1 see
it, with the existing OSMA standards of a continuous 90 dBA limit
for an 8-hour period.
-?3. P-igc V1" ° H. Th': contents of Table III-.'"-2 at the top of the page
lucks JMSI a\ cation. The phrase "most likely" in i.he note is
di sturbi j>;'>' pro1 nineni.
44. Page '1II-3- . 7. First rul] paragraph. Note the word "assumptions;"
and tin"- pi~ -;?.se n'Mghl locr' ihe second last sonlono''' of (his
paragraph. In -^IdHit''', ^-o pp.^se "i! i--. judfv -:' (n.-.vnj-blo V
reconu'rienc an ' .?}r (:" S. ciH ar the ma.>;i:r,u:-."; P-..T. .'.is.-:;!/.-!^ yoai'iy
oui.r'oor- .-ivr-i-afc .vou.-.o !<:\(xl" (liiuiersctji i;)<; supplied), points ur> !ne
i'aci th'.il. tiuL rei:^,rn;.(.-::::;;!ion is based on assumptions, expectations.
and coined lire. In i':u:i the whole paragraph is ;i iiypoDi^sin ;ind not
based 01; proven scientific data.
45. Page I!!~;:'-8. Tho fii'st paragraph indicates thai in "choosing
suitable- anms . . . it appears reasonable to limit ..."
Certainly such a choice, is not based on scientific proven data.
46. Page I']-''- 8. FMSI tv.n-af;vriph.. In i-x>.(i niirldle of Iho- par;.'.gr:xpli it is
stated that "a r-c-w soinble ri-itor'ion value ... is 45 rlB. " The
basis foi clioosiii;.; liiis level is highly questionable b(>cause of the
lack of sufficient scientific supporting data. Also the word
"assuming" at the beginning of the last sentence is prominent.
11-31
-------
-9-
47. Page III-3-11. The first two sentences at the top of the page.
I am disturbed by these two sentences because it indicates that
the survey of respondents to questionnaires can result in
correlation between annoyance and noise exposure. This might
be true, but only if the survey questionnaires on the noise subject
are appropriately worded and the subject properly approached and
presented by the questionnaire. This certainly was not true in
the Tracer Study. The questionnaire was 90 to 95 percent
strictly "noise" oriented. Obviously this kind of questionnaire
leaves the respondent to focus entirely on noise and be lead to
focus entirely on the noise problem. The result can often be
warped replies. Thus, correlation between annoyance and noise
exposure cannot be made on the basis of such questionnaires.
For the same reason I quarrel with the last sentence of the last
paragraph on this page.
For the same reasons I am concerned with the last sentence of
the first full paragraph on the page.
48. PageIII-3-11, second full paragraph, second sentence. The
phrase "seems reasonable" is prominent.
49. Page III-3-11. Regarding the third and fourth paragraphs, refer
to comment 47 above. We are not familiar with the Heathrow
Survey, but we are with the Tracor questionnaire. We, therefore,
question the relationship between the number of complaints and
the number of persons highly annoyed. If the Heathrow Survey
questionnaires were anything like that used in the Tracor Study,
the result of those two surveys are equally questionable.
50.. Page III-3-13, second full paragraph. Reference is made to a
"55-case study described in Appendix III-IV. " I would submit
that a 55-case study does not give a very sound statistical base
from which sound conclusions can be reached.
51. Page III-3-14. In the last sentence starting on this page, it is
recommended that exposures to levels below 80dB is considered
acceptable. Apparently it gives 5 dB more protection then provided
by the Occupational Safety and Health Administration Act of 1970.
Why should the recommendation be more conservative than the
OSHA standards, particularly, as there is lack of knowledge as to
the acceptable levels at this time.
H-32
-------
-10-
52. Page III-3-15, second full paragraph. Note the word "potential"
in the first line of this paragraph.
53. Page III-3-15. The general tenor of this page leaves the impression
that there is no clearly established noise levels which distrub sleep,
yet a most conservative level is proposed without the benefit of real
proof.
We are particularly distrubed by the fact that the recommendation
that peak sound levels during nights be controlled by separate
local noise ordinances. This would mean that every jurisdiction
into which an airplane operated would be permitted to establish a
peak sound level for night operations. It would be impossible for
a national air transportation system to be operated under such
conditions.
54. Page III-3-16. The 10 dB figure and 60 dBA figure set forth in
this paragraph are questioned as not being based on provable facts.
The phrase "will most likely cause no adverse effects" is
prominent.
55. Page III-3-16. Second paragraph under "NATURAL INDOOR NOISE
'FLOOR'". Note the phrase "are considered representative. ::
My question "Considered representative" by whom and on what
basis?
56. Page III-3-17. Second paragraph. First line please note the
phrase "it is reasonable to conclude". Where is the proof for such
a conclusion.
57. Page III-3-1 7. Third paragraph. The phrases "a typical house"
in the third line as related to the noise level "15 dB" in the fourth
line, indicates the kind of non-specificity upon which sound rules
cannot be based. In the second last sentence "expected to produce"
appears. This again shows lack of a sound data upon which a rule
must be written.
58. Page III-3-1 7. Fourth full paragraph. The phrase "It is concluded
that" appears in the first line. Again where is the real proof for
such a conclusion.
59. Page III-3-1 7. The phrase "preliminary estimate" in the fourth
line is prominent.
H-33
-------
-11-
60. Page III-3-18. Table III-3-6. In the first sentence of the table
the words "Estimated Number of People" is prominent.
61. Page III-3-18. First full paragraph. Note the word "estimates"
in the first line, third line, and fifth line.
62. Page III-3-1 9. Note the word "estimated" on the first line of the
page and the phrase "may be the subject to risk of hearing damage1
in the third line.
63. Page III-3-19. The last full paragraph on this page is full of
questionable facts, estimations, and apparent conjecture. The
information set forth here should not be used as a basis for
recommendations to the Congress.
64. Page III-3-21. This page consists of Table III-3-7, and is a
summary of many of the conclusions, estimates etc. previously
discussed. We, therefore, question the validity of the information
contained in this Table.
65. Page III-4-1. Paragraph 2. In line with previous comments, it is
suggested that the following part of line 4 and 5 be eliminated: "it
can be related to other more complicated methods in use for special
applications as discussed in Appendix III-I. "
66. Page III-4-2. In the fourth last line, it is suggested that the phrase
"have a definite" be replaced with the word "may" and the word "on"
be deleted.
It is also recommended that the last full sentence in this paragraph
be deleted for the reasons stated earlier, i. e. , we need one and
only one measure of aircraft noise for emissions, certification,
enforcement, et al.
67. Page III-4-2. Paragraph 3. As mentioned in comment 2 above.
it will be impossible to establish an average cumulative noise
exposure for individuals. There is no regulatory method to apply
a cumulative noise exposure limit to individuals and enforce the
regulation.
68. Page III-4-2. Paragraph 4. As mentioned earlier we do not believe
that this conclusion is based on sufficient facts to be viable. The
same is true for conclusion No. 5 which follows.
TI-34
-------
-12-
69. Page III-4-3. The same is true of conclusion No. 6 on this page,
and that of conclusion No. 7 which follows.
Continuing on top of Page III-4-4. Again, we point out the
impossibility of continuing a national air transportation system
with noise levels being controlled by local authorities.
70. Page III-4-4. Paragraph 8. As stated in previous comments, it
is necessary to use one measure of noise. That should be dBA,
and apply to all noise sources, emission rules, certification
standards, enforcement procedures, etc.
71. Page III-4-4. Paragraph 9. This conclusion is not supported by
scientific evidence, and certainly not by this draft report.
72. Page III-4-5. Paragraph 2. As stated in several comments above,
the aircraft noise descriptor should be used for certification,
emission rules, et al, in addition to those purposes set forth in
this paragraph.
73. Page III-4-5. Paragraph 4. Again, we feel that the outside
cumulative noise exposure level T/d-i °^ ^ dBA. recommended
here, is not supported by the facts available at this time. There-
fore, we do not concur with this proposal.
74. Page III-4-5. Paragraph 5. For the reasons set forth in comments
above, we do not concur with this recommendation. It is not
based on scientifically supportable facts.
75. Page III-4-6. Paragraph 6. Again, for the reasons set forth in
earlier comments, we do not concur with this recommendation.
It is not based on scientifically supportable facts.
76. With respect to Appendices III-I, III-II, Ill-Ill and III-IV, our
previous comments have effectively questioned the validity of
these appendices as not being sufficiently based on scientifically
provable facts, but on assumptions, approximations, etc.
H-35
-------
July 2, 1973
Mr. Henning Von Gierke, Chairman
Task Group III
Aircraft/Airport Noise Report Study
Environmental Protection Agency
Room 1107
1921 Jefferson Davis Highway
Crystal Mall Building, No. 2
Arlington, Virginia
Dear Mr. Von Gierke:
Enclosed you will find a copy of the Airport Operators
Council International's comments on the draft report of
Task^Group III of the Aircraft/Airport Noise Report Study
Donald
Executive
sident
Enclosure
H-36
-------
TASK GROUP III
AOCI Comments On
Impact Characterization of Noise
Including Implications of Identifying and
Achieving Levels of Cumulative Noise Exposure
For
Environmental Protection Agency
Aircraft/Airport Noise Report Survey
There is no objection to the use of a time integrated
dBA for single event measurement. There is also no
objection to the L^ methodology to quantify cumulative
noise exposure. In the final analysis, it is a simpli-
fied CNEL measurement and is similar to the many other
systems now in use.
Our quarrel is with the interpretations of the impact
of the numbered contours generated by the methodology.
There is a major objection to the use of the 80 Lj-^
level as a limit for health and the 60 Lp^ level as a
long range limit for health and welfare. These levels
appear to have been selected as a judgement by the Task
Group Chairman and the acoustical consultant to this
group without sufficient back-up data or studies to
support the recommendation. It also appears that studies
such as the HEW Study of hearing around Los Angeles Inter
national Airport have been left out as they do not
support these conclusions. There is also evidence in
the Report that the levels were selected on the basis
of data on an eight (8) hour steady work environment
exposure rather than the peaking type of exposure from
aircraft overflight. Abundant evidence exists that the
effects of these two types of exposure on people are
drastically different in toleration and auditory recov-
ery capability. Presentations at the recent Dubrovnik
conference clearly indicated that at this time there is
insufficient data to establish limits for health and
welfare purposes, therefore additional work is needed.
H-37
-------
- 2 -
The impact of many recent court decisions regarding
noise have also been ignored. These decisions are
beginning to define a specific pattern that cannot
be ignored if any proposed regulation is to stand up
before court challenge.
While we have been told that EPA will not try to set
tolerance levels at this time, nevertheless, the levels
are in a published draft report. We state again that
the levels are without adequate scientific foundation
and before any levels are set, greater in-depth studiss
are required. Therefore, we recommend that any figures
utilized by EPA in its final report to Congress be
submitted with a caveat that no clear scientific data
exists to substantiate use of the figures themselves
or the application of the methodology for purposes pro-
posed by the report.
H-38
-------
CITY OF LOS ANGELES
DEPARTMENT OF AIRPORTS
' 1 WORLD WAY LOS ANGELES, CALIFORNIA 9OOO9
TELEPHONE (213) 646 5252 - TELEX 65-3413
0 I ITTON A MO OH P..
June 29, 1973
Mr. John C. Schettino
Aircraft/Airport Noise Study Task .Force
Environmental Protection Agency
1921 Jefferson Davis Highway
Crystal Mall, Building No. 2
Alexandria, Virginia 20640
Dear John :
This is th:: final version of my letter to
Dr. Alvin jr. Meyer, Jr. I believe you had an
earlier draft which was incorrect,
Cordial"1 y,
.
Clifton A. Moore
General Manager
CAM: Is
n.!i!iiii.-«ift\ H-39
OOArO OF AIRI'OHT COMM ISSION INS
\n-/./i,vl f t!i!li,ii',,'r. 1'KI .>//>/ .7 . l...h,-rl :i ,V,;,,,.. ,,j. I /( I I'/,'I\I/H W . ( I .-nu.-Hf lli.inrlur,! \M>,«J tnckw \-,'nl\.,,:, I. Q,,:,w. .\t.[l.
-------
CITY OF LOS ANGELES
(-V ' V ^- DEPARTMENT OF AIRPORTS
\ ,-^^
»«- ""«» ___, . (- i '1 WORLD WAY LOS ANGELES. CALIFORNIA 9OOO9
,,., TELEPHONE (213) 646-5252 TELEX 65-3413
June 26, 1973
CLIFTON A MOORE
MEMORANDUM
TO: Dr. Alvin F. Meyer, Jr.
Deputy Assistant Administrator
for Noise Control Programs
Environmental Protection Agency
FROM: Clifton A. Moore
General Manager
SUBJECT: Comments -- Draft Reports, Task Groups -- Airport Noise
U .-.,»,-* ^.^^^.i*. ,1-,, ,.
AXtX V ^ ^MX \^X Crf-k.JL.' 1
airport noise. These reports are to be used as inputs into EPA to aid in
the preparation of the report to Congress required by Public Law 92-574.
In general, I do not have major problems with the recommendations as a
whole; however, great care must be taken in the wording for feasibility,
safety, timing and financing to be sure that the requirements of the Public
Law for maximum safety and economic and technical feasibility are met.
When consideration is given to Lj-^ limits for health and the Lj-,^ limits
as long range goals for health and welfare, great care must be taken in
the language of the report that interprets the standard so as not to draw
definite conclusions on health and welfare effects until many more studies
are completed and more definitive data is compiled. The Environmental
Acoustics- -HEW study at LAX, as well as other studies around the country,
cast considerable doubt as to the recommendations in the Draft No. 3 report
of an Ljpjxj 80 limit for health and the Lpjg- 60 limit for health and welfare.
The Dubrovnik meeting papers for 1973 further support the need for more
data.
Sorn Yorfy, /ViOyO""
H-40
BOARDOF AIRPORT COMMISSIONERS
t \t fttHmrw. 1'ICf /'A'/.SV/>/ \7 - ( I smnt.'r ttbmlwti . t/,7u/i J tntkHm , lii//«im f. Q-.nnn.
-------
Dr. Alvin F. Meyer, Jr. -2- June 26, 1973
Recommendation No. la of Task Group No. 1 (Legal) that the FAA would
make the California State Standards of CNEL effective in California only
is patently unfair to this state, is unacceptable, and in our opinion probably
illegal. As with the Lj)N numbers mentioned in the previous paragraph,
more supporting data is needed for the impact numbers used in the Cali-
fornia Standards. As you know, these standards are under attack in the
courts with the ATA lawsuit and from all indications will probably be
overturned. In lieu of this recommendation, I would like to suggest the
following alternative: The LAX sound monitoring system is capable of
being programmed to compute CNEL or LQ^ measurements. As an
experiment and in order to establish the effects of proposed national regu-
lations on a major airport and the country, we would supply the data to
EPA from the monitors in either impact system that is desired. This
would give a comparison of the measured versus the calculated impacts
and would permit an evaluation to be made of the overall land areas within
the various impact contours. This would give valuable data that could be
used along with other data in the selection of final numbers for health and
welfare.
We strongly support a retrofit program for all non-Part 36 types of aircraft
operating into our airport both foreign and domestic. The program must be
programmed to be completed by the year 1980 or before. The Fleet Noise
"Rule (FNL) staffing of the program is acceptable for managing the program
and seUing ilie iiiiiia^ oi Compliance. In this manner, all aircraft v.'ill
meet or better the Part 36 noise limits by 1980.
Financing of the retrofit program must become a part of the rule-making
procedure. We have long advocated a one to two dollar charge per airline
ticket and a small percentage to be added to each airfreight waybill as a
means of financing the program. The charge is the least expensive way
(insofar as the user is concerned) of paying the cost and should be dropped
when retrofit is complete. This grant to the airlines should not be taken
into the airline accounting system and should not be capitalized.
In line with financing noise costs, the ADAP funding to airports should be
changed to permit the acquisition of land and/or easements for noise
purposes under the program. Land acquired for noise is just as important
to the airport as land acquired for approach lights or other facilities.
We strongly support changes in flight procedures that reduce flight sound
levels provided theie is no reduction in safety or operational minimums
for the airport. The two segment approach, the flap managed approach,
and the development of two departure profiles seems to be approaching
acceptability under this criteria as a result of flight tests. When proven
they should be mandated. However, such regulations must be issued by
the FAA.
H-41
-------
Dr. Alvin F. Meyer, Jr. -3- June 26, 1973
In the matter of flight procedures, it should be made very clear that this is
an area where the airport owner cannot dictate policy. There are safety,
liability and expertise reasons why the airport cannot become involved in
the flight techniques of aircraft. While we obviously will coordinate com-
pletely with the FAA and the airlines in developing flight procedures and
pointing out problem areas around our airports, the procedures must be
flight tested and specified by the FAA.
The Task No. 3 effort to develop a single event measurement system and
a cumulative noise exposure impact methodology is generally -acceptable.
Obviously, more detailed study is needed. We would suggest that there be
only one health and welfare number and that this number be selected only
on a preliminary basis subject to evaluation and confirmation pending defi-
nitive field studies around noise sources to determine areas involved and
additional scientific studies of the effects of various cumulative levels.
Airport certification for noise would be a problem with present procedures.
Noise certification can only be contingent upon the full completion of the
retrofit program to Part 36 or better standards. A staged approach to
certification could be acceptable if full compliance is not required until
after the tools are available to meet certification requirements such as
retrofit, flight procedures, funding of programs, and also rights and obli-
"E"1 A A or* TTrc^ll P Q T~* v/~* r~* VI cvf/^y* ovo fY* /^ T* O r*~\ Ct o v*l tr rl o -f-i vi ca rl
' - -
I trust that these comments will be helpful to you. If I can be of further
assistance, please call me.
Cliftc
Gene
n A. Moore
al Manager
CAM:BJL:sm
H-42
-------
25 KNOB HILL ROAD, GLASTONBURY, CONNECTICUT 06033
203 - 633-2835
Rational Organization to Insure acSound-controlled Environment
Dr. Kenning Von Gierke, Chairman June 30, 1973
Task Group 3
Aircraft/Airport Noise Study Report
U.S.. Environmental Protnetion Agency
Building 2, Crystal Mall
Arlington, Virginia 20460
Dear Dr. Von Gierke:
I have attended all of the meetings of Task Group 3 and have
reviewed the Draft Report on "Impact Characterization of Noise
Including Implications of Identifying and Achieving Levels of
Cumulative Noise Exposure". I have been familiar with and
participated in the reasearch in this field for many years.
Our organization presents the following as our position on
this subject:
1. Since the research in the field of human reaction to noise
overwhelmingly Indicates that humans react to cumulative
noise exposure we support the use of a cumulative noise
scale.
2. We support the use of noise energy as the basis for
cumulative no* -» exposure.
3. We support the use of a 10 dB higher weighting of noise
during the sleeping period (2200 -to 0700) than during the
daytime.
4. We support the use of L^ = 60 as the criterion for outdoor
noise in single family residential areas.
While we recognize that the setting of a criterion or standard
of L « 60 will not mean that the noise in all residential
-------
Dr. Henning Von Gierke June 30, 1973
Page 2
areas will be reduced to this level immediately we believe
that It is well to have this criterion established now and to
start work to bring noise in residential areas down to this
level as soon as possible.
Sincerely,
\V\
Jotfi\ ivi. Tyler, Exec/qtive Director
-------
COMMERCIAL AIRPLANE COMPANY
P.O. Box 3707 Seattle, Washington 98124
June 29, 1973
6-7270-1-443
Dr. Henning E. von Gierke
Office of Noise Abatement and Control
Environmental Protection Agency
Washington, D. C. 20460
Subject: Boeing Commercial Airplane Company Position on Task Group 3,
"Impact Characterization of Noise Including Implications of
Identifying and Achieving Levels of Cumulative Noise Exposure. "
References: 1) Boeing Letter 6-7270-1-442, V. L. Blumenthal to
R. L. Hurlburt.
2) Boeing Letter 6-7270-1-444, V. L. Blumenthal to
W. C. Sperry.
3) Boeing Letter 6-7270-1-445, V. L. Blumenthal to
W. C. Sperry.
Dear Dr. von Gierke:
In response to the request made by Mr. John C. Schettino in his letter of June 25,
1973, the Boeing Commercial Airplane Company wishes to include only this letter
in the final report of Task Group 3. Therefore our Task Group 3 letters of
April 2, 1973, and May 24, 1973, should not be included. References 1, 2 and 3
contain our position letters for Task Groups 2, 4 and 5.
In some of the Task Group draft reports it clearly states that the conclusions and
recommendations are the responsibility o£ the chairman. We endorse this position
and agree with it completely as being the only reasonable and fair manner in which
such reports could be written. Because of the variety of opinions espoused in the
Group discussions, and because generally no formal attempt was made to obtain a
consensus, we would suggest that any inference of unanimity of opinion be
expurgated.
H-45
A DIVISION OF THE BOEING COMPANY
-------
- 2 -
Dr. Henning E. von Gierke 6-7270-1-443
We are deeply concerned about airport noise exposure and Group Three's objective
of characterizing airport noise. We recognize the need for, and support the goal
of, reducing aircraft noise exposure within airport communities. However, as
discussed in our reference 2 letter, all recommendations leading to the formulation
of noise standards must consider both the cost and the end result for which they are
created.
The Boeing Company has encouraged and participated in the development of methods
for rating human response to noise. Several noise rating scales have been developed
in an effort to account for both the variability in individual response to a given
noise, and the multitude of different sounds to which people are exposed. Commun-
ity surveys have shown that noise alone is a poor indicator of annoyance. At present
no subjective scale, including the new L , unit used in this report, can provide more
than a crude estimate of community response to a complex sound. Such deficient
scales are not suitable for making major decisions and could result in costly
mistakes.
We believe that the method and responsibility for allocating noise reduction burdens
or design objectives among various noise sources (autos, trucks, airplanes, construc-
tion, playgrounds, trains, etc. ) which contribute to the cumulative noise level must
be defined. Only in this way can a manufacturer determine the exact criterion by
which his product should be designed in order to satisfy the established noise
exposure limit.
Sufficient data are not available to provide definitive maximum values of noise
exposure. The potential impact from the establishment of a maximum acceptable
noise level that will protect the public health and welfare is so great that all facets
must be understood. We suggest that a national research program to produce criteria
which reflect the complex relationship between noise, the people's health and welfare,
and the economic ramifications be vigorously pursued.
It has been our pleasure to participate in the Task Force effort and we feel these
comments will be of value to the EPA.
Very truly yours,
BOEING COMMERCIAL
AIRPLANE COMPANY
<$^>j^^\tl^^
V. L. Blumenthal
Director, Noise and Emission
Abatement Programs
H-46
-------
General Aviation
Manufacturers Association
Suite 1215
1025 Connecticut Ave., N.W.
Washington, D. C. 20036
(202) 296-8848
GENERAL AVIATION MANUFACTURERS ASSOCIATION
COMMENTS ON THE
DRAFT REPORT
ON
IMPACT CHARACTERIZATION OF NOISE
INCLUDING IMPLICATIONS OF IDENTIFYING AND
ACHIEVING LEVLES OF CUI-iULATIVE NOISE EXPOSURE
FOR
ENVIRONMENTAL PROTECTION AGENCY
AIRCRAFT/AIRPORT WOISE REPORT STUDY
TASK GROUP 3
June 20, 1973
H-47
-------
The General Aviation Manufacturers Association has been pleased to
contribute to the work of Task Group 3. Specific conrcents on this
report are as follows:
1. The unit I^jn appears to be reasonable and justifiable from a public
health and welfare viewpoint. However, it is not clear how the unit
would be used for establishing regulations. Indeed, an L^ of 80
must be related to existing or pending aircraft noise regulations
before the impact on the aviation industry is properly understood.
In addition, as other noise sources exist around an airport, what
preferences would be adopted in controlling the L^ to a specific
number? It would appear that a responsibility of Task Grcap 3 in
characterizing a unit and an allowable magnitude would be to delineate
how these recommendations could be used in a practical, sense. GAMA
expresses its concern in this regard and respectfully requests
clarification from the EPA.
2. A considerable amount of work has been expended by GAT-5A, other in-
dustry associations, and U.S. and foreign governments, to formulate
new ICAO/FAA regulations for geaeral aviation aircraft. These pending
regulations represent a sincere challenge in noise reduction and,
indeed, tax the capabilities of the general aviation industry. GAMA
requests clarification from the EPA on the specific relationship
between its recoranendations and the pending ICAO/FAA regulations.
3. If it is assumed that explicit answers to items (1) and (2) above are
forthcoming, the questions arises as to the economic impact on the
aviation industry, as a whole, resulting from the Task Group's
recommendations. The economic impact has not been addressed, even
superficially. GAMA recognizes that, in the time available to the
task group, it would have been difficult to obtain the necessary
information. However, GAMA believes it would be irresponsible to
endorse recommendations without prior knowledge of the economic im-
pact on the general aviation industry. Consequently, GAMA requests
that the EPA furnish a clear picture of the economic impact resulting
from the. recorareridations,.
GAMA endorses the goals to control noise for the benefit of public health
and welfare, and will cooperate fully in establishing responsible recom-
mendations, consistent with the health of the general aviation industry.
H-48
-------
INCE
INSTITUTE OF NOISE CONTROL ENGINEERING
K. Uno Ingard, 1973 President
Room 20F-104
Mass. Inst. of Technology
Cambridge, MA 02139
2 July 1973
Mr. John Schettino
Environmental Protection Agency
Room 1107 - Bldg. 2
1921 Jefferson Davis Highway
Arlington, Virginia
Subject: Draft Report on "impact Characterization of Noise
Including Implications of Identifying and Achieving
Levels of Cumulative Noise Exposure"
Dear Mr. Schettino:
On behalf of the Board of Directors of the Institute
of Noise Control Engineering (INGE), I would like to extend our
hearty endorsement of the principal accomplishments of Task
Group 3 which are embodied in their report.
We find that the report contains an excellent and
balanced summary of the principal human effects of noise.
We concur in the urgent national need for a single noise
scale for cumulative noise exposure which can be applicable to
noise from all origins, and we endorse the Task Group's selection
of the Day-Night Average Sound Level for this purpose. This
proposed measure of noise combines the best features of the
several complex measures developed during the past two decades
for assessing cumulative exposure to aircraft noise with the
simplicity of the A-weighting which is utilized in the basic
sound level meter to account for the frequency characteristics
of a noise. We feel that the A-weighting is sufficient for
cumulative outdoor environmental noise although more complex
measures may be appropriate for source noise standards and
engineering purposes. Furthermore, since A-weighting has been
in common use over three decades, A-weighted sound level data
are available for almost all noises; see, for example, the
"Report.to the President and Congress on Noise," Senate
Document No. 92-63, 92d Congress, 2d Session, dated February
1972, Report of the Administrator of the Environmental Protection
Agency in Compliance with Title IV of Public Law 91-604, The
Clean Air Act Amendments of 1970.
We agree that it is essential to state a national goal
for cumulative noise exposure to enable systematic progress
H-49
-------
Mr. John Schettino 2 July 1973
Environmental Protection Agency Page 2
toward necessary improvement of the noise environment. We
endorse the report's recommendation that "... a yearly outdoor
day-night average sound level of 80 decibels in residential
areas should, as soon as possible, be promulgated as the
permissible limit with respect to health alone." In addition,
we concur with the recommendation that "A yearly outdoor day-
night average sound level of 60 dB should be the long range
limit of the EPA for environmental noise quality in residential
areas with respect to health and welfare. ..." This recommended
long-range limit is consistent with current knowledge.
Sincerely yours,
-------
DEPARTMENT OF THE NAVY
NAVAL. UNDERSEA CENTER
SAN DIEGO, CALIFORNIA 92132 IN REPLY REFER TO:
401/RSG:mvg
2 July 1973
Dr. Alvin S. Meyer, Jr.
Deputy Ass't Administrator
for Noise Control Program
US Environmental Protection Agency
Washington, DC 20460
Dear Dr. Meyer:
I have been requested by Dr. Edgar Shaw, President of the Acous-
tical Society of America, to review and provide comments to you on the
Draft Report of 1 June 1973 of Task Group 3 on "Impact Characteriza-
tion of Noise Including Implications of Identifying and Achieving
Levels of Cumulative Noise Exposure".
The short time available for review of the report precluded an
in-depth study. I am, therefore, constrained to make my comments an
overview of the general aspects and basic philosophies embodied in
the report with particular emphasis on the conclusions and recommenda-
tions . My comments follow.
1. The basic requirement stated in Conclusion 1, the adoption of
a common measure applicable to environmental noise from all types of
sources is of critical importance, and the selection of Sound Level A
for this measure is in accord with recommendations of Working Group
S3-47 (SI) of the American National Standards Institute (ANSI). This
group is assigned 'Evaluation of Noise with Respect to Human Response",
and its membership consists of the chairmen of all ANSI Working Groups
dealing with noise which have a relationship to human response.
2. The use of Lj^, employing an energy-type integration of
sound pressure squared and time is fundamentally sound, and is also
in accord with recommendations of ANSI S3-U7 (SI).
3. It must be recognized, as pointed out in the report, that the
basic measures recommended have been shown to be useful predictors of
first order effects on man. These primary effects are the ones which
I believe are capable of being treated in the current time frame, and
it is clear that timeliness of action is an essential part of the Noise
Control Act of 1972. The report under discussion properly utilizes
state of the art, and very appropriately identifies as secondary, such
issues as tone corrections, improved weightings, etc. These are subjects
worthy of research which may lead in the future to possible minor
revisions of sound ratings, but are not of such importance as to warrant
postponement of action.
H-51
-------
4-. In adopting T_,,^n as the primary measure o.
mat ion as to "the time pattern of the eou;ii_ is eli;.
properly notes chat the Lime struct*.re of a cound
ant element in the human response (hearing j..~...r-s c
annoyance, etc.). Research should be conci:i;:ed o;
at least for speech interference and hearing .loss the ele.:,eiH oi vari-
ance in the time pattern is probably such ^s LO raake L^ a conservative
measure as applied to aircraft noise. The areas of annoyance, sleep
interference, and physiological effects (.ail of which are difficult to
quantify) may be more critically dependent on specific tiirse patterns
of variability. The report quite properly points cut t:;a I control of
the intermittent and occasional noise of short duration :i:c.-y require
measures other than L£n . These might be :uaxii!ium sound level, single
event noise exposure level, etc. It is quite appropriate that these
be embodied in local ordinances as stated on page III-3-l^, particu-
larly for comfort and sleep. This will nec.'d addlrlor.al ; Ltentic-:.' in
the future.
5. I believe it is important that wnere the report s;:aaks ci
"health" in the sense of dealing with hearing conservation, attention
should also be given to the lesser known effects o7 noise en health.
mediated through such physiological effects as heart ra'T-., b]oou
pressure, etc. This is dealt with briefly in the section ConeraJ_
Health Effects of Noise on page IIl-3-m. The. inipiical ic:: tnat ii:
noise is held down to levels which protect hearing it i?. -.iuJ.ikclv
that other health effects will occur appears to be an over ^onerali-
zation. Although I know of no data to the contrary, -
possible that patterns of fluctuating noise .nav exist
not exceeding 80 dB might possibly produce acver;-:^ =r.
nervous and vascular systems. Again, I believe tacit :
be used as an excuse to postpone action, but as.a renr
alert to future findings.
G. The limits proposed L-io 80 dB ' "" "'
chosen compromises between ideal and pr.
In summary, I believe the Task Force :
timely document, well-conceived toward the
Control Act of 1972.
_^>.^ /'s-< -
R, S . GALES
HEAD, ACOUSTICS, BEHAVIOR &
COMMUNICATIONS i;IVISION
liopy to ;
John Sc.h-ii.tino H"'52
.-2"
-------
DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT
WASHINGTON. D.C. 20410
ASSISTANT SECRETARY FOfl
COMMUNITY PLANNING AND MANAGEMENT ...
1973
Mr. John C» Schettina
Director, Air craft/Airport Noi»» Study
Office of Noise Abatement and Control
Enviromaentai Protection Agency
HMhiagton, D. C. 20>»6O
Dear Mr, Schettinoj
W» would like to tak« this opportunity to express our .general satis-
faction with tha work of EPA Task Force which was organized to provide
recommendations for dealing with th'e aircraft/airport noise problems*
Unfortunately, we were able to provide only .limited assistance to
three of the i'ask Groups due to staff shortages and other pressing
assignments; however, I aa enclosing our general observations and
position on raaay of the preliminary recooaoendationa of tb« Task Forc««
T#fe will continiie to aupporu the activities of tha Environmental
Protection A^.--^y in the aircraft/airport noise pro^rsaa, and will b«
happy to provide whatever assistance we can to the SPA la tbla effort.
Since
Enclosure
-------
Depur- J.ent of Easing and Urban Dev>r' oytn-'
wi^imentc; on
JffiCCMMEJHDATIONS ON TRS EFA VA^d FCrcCE ON AISCPA»v../ALICK.r/i NOISE PROBLEM
A. HUD's ROLE IK NOISE ABATEMEM1
It has long been HUD's policy to encourage r.be creation and maintenance
of a quiet environment. To further this goal, HUD issued- on Augus* ;*.
1971, a policy Circular on "Noise Abatement and Control: Departmental
Policy, Implementation Responsibilities and Standards." This ].vui cy
was promulgated after several yeers of development, in an effort r.o :'.!..
fill the Department's mandate to "provide a decent, hoae arid a suitslv.f:
living environment for every American family", with the issuance of 1:..;
policy. HUD stated its conviction that rnoise is a major source oi envi-
ronmental pollution which represents a threat to the serenity arv': qua.-..!.
of life in population, centers." The policy formalized and expanded
existing FEA noise regulations which ha;: i^-.r, in effect, .01- aitir. ysaa-.,
and drew upon the work of several other' agencies and groups and or-, s.
long standing and developing body of knowledge in the >.r«a..
The policy establishes noise exposure policies and standa-dn to be o,^
served in the approval or disapproval of all HUD projects; it suixo-iv-r.
those por~H ons of oy? «?t.-ing prog.ra.Tr regul?.v.'io"C "r.i
/c Icoo ddiuauJliig iioibe exposure rscuirj.-i:'cs. : .ru.ic.r, IT, s
HUD's general policy to foster the creation of concrclt a;~d standaroj:
for community noise abatement and control by general purpc.i-o acsnci^:^ r'
State and local governments. HUD also requires that ncise exposure.;- ar..-:
sources of noise be given adequate consideration as an integral part of
urban environments in connection with ail. HUD programs wnich provide
financial support to planning. The policy enpha^izes (;-.-:. :.:;;.cri.anc^ c '
compatible land use planning in relation to airports, ot;v~r general n>cd ;
of transportation, and other sources of high_noise, and supports the u-j-.-
of planning funds to explore ways of reducing environmental noise to
acceptable exposures by uss of appropriate methods. Reecv.missaKCe
studies, and, where justifiable, studies in depth for noise control and
abatement will be considered allowable rosts.
Because HUD's noise standards are technically specific in 'aatare, the
Department has published "Tcise A.TS-5Ssr:-./r:t "uicii.vlir.es::, a ;vir:r.al tc ire-
vide HUD's personnel and the general public with a praoti«-v:,.L ir.ethodoic-',;-
for preliminary evaluation cf noise levels at given prr-.jo.. '< sites. An
iffiporta>7t facet of the Department's noii:e control activL:,.':;: is a con-
tinuing program of sponsored research into various aspect.r- .vf tlie i.-.:..i:.-.?
ana effects of environmental noise. Typical of these ; = : series oi'
Metropolitan Aircraft iYoise Abater,v;nt Policy Stur':.ies, 'i;.j:-v ''- ,jointly . y
HUD and the Department of Transportation. This work was .-.uiamarized and
H-54
-------
-2-
extended in the form of a guideline manual, to help localities plan com-
munity growth in the vicinity of airports. The manual discusses the costs,
benefits and limitations of alternative methods of noise alleviation such
as compatible land use development, zoning, and noise attenuation measures
in "building construction. Applicable to «-ii type of airports, it will be
used to develop procedures for dealing with a variety of local airport
noise situations. It also contains relevant information on Federal and
State programs to assist in achieving compatible airport-community de-
velopment. The manual entitled "Aircraft Noise Impact: Planning Guide-
lines for Local Agencies," is now in printing by the Government Printing
Office and will be given wide distribution.
B' HUD's POSITION ON ISSUES REIATED TO THE WORK OF THE TASK FORCE
' Cumulat ive Wo i s e Expos ur e
We "believe that there is an urgent need to standardize a measure of noise
exposure as a prerequisite to promulgating a national set of noise exposure
pt'-;v'?ird.s and implementing procedures. We> therefore, strongly support
th. activities of Tasi. Group 3- The lack of what might be called a
"perfect" index of measure is no excuse for inaction on the growing prob-
leiur; of noise abatement and control. Our major concern is that any pro-
posed airoi"r>fM" ^cis0 ''-^pp-nont method tr? >on|pa't-i'bl~ T-.Tit-h those n~v in. *.i£2
by t,hi:' Department in implementing the KLTD noise policy, i.e,s Composite
?\fcr se Rating (CNR) or Noise Exposure Forecast (KEF),
,:£ in agreement with the long term goal of Ldn of 60 (NEF 25') recom-
me ....ed in the Task Group report; though we feel that further clarification
:i . ;.ie>-:fled. Current HuD policy is to discourage residential development
'*'.' -"iiid 30 NKF (t'.'OV^b .r:on?e discretion is applied in certain cases whe.re
<--(: exposures li.;; >-::-uv/eer. .KEF 30 and Uo'io The KEF 30 value corresponds
:.' :;i';j.y to an Ldn of :<5. Thus, the current allowable noise exposure for
'-... a.::oiated now r-:s.i.T.9.ntir3.I const-ruction is marginally higher than the
.;'.. .; i..v.n''. goal a sci-mr^nded loy the Task Grou.p. However, we fully bope
;- .'jntioipatr that ih?. EPA, with T.be cooperation of other Federal afren-
,; and. industry groups, will be successful in reducing noise through
::<. s.rd operat:Loria.i. controls, so that noise reduction from these activ-
-!.. 'vill bring cvrrent residential construction satisfying r.xistinr; ^'IrD
.-.vi-x well vithxrj Los l.o/i:-, term objective (Ldn of 60). It i?. imports.nt
, :.!..r.'n.risize tho.t sii'ice new construction represents the long term estab-
. .:;;:,; o:f a .'^.'.:;?ij l;^>d v.: .._ to j payiiicujL.ar area, ijnpl^iifiivLfxtioi';. of loivv;
-....!. ..onis require? imrnediete action of the type IFJD has ba^n actively
-------
-3-
We assume that the immediate goal of Ldn (45 NEF) of 80 is to be imple-
mented through source and operations controls, building modifications,
and where necessary, condemnation and relocation, and is to be applied
to existing residential units. We fully support such a recommendation
providing adequace relocation resources are available at a price the dis-
placees can afford (pursuant to provisions of the Uniform Relocation Act).
We are concerned, however, that noise levels less than Ldn 80 may also
constitute risks to health resulting from sleep interference, unless
airports have stringent restrictions on night-time operations. The pro-
blem is exacerbated with windows open, as they must be in the summer
months in many areas when adequate alternative ventilation is not avail-
able.
We support recommendation concerning a standardized computer program for
calculating cumulative noise exposure. Further, there should be a stand-
ardized definition of data input requirements and a central data center
which can generate contours of cumulative noise exposure for use by Federal.,
State and local agencies in making land use decisions.
2, Airport Noise Regulation
We would endorse the recommendations that airport operators exercise their
authority to regulate aircraft operations to reduce noise in residential
areas. The requirement that airport operators predict operations and noise
exposure Lu determine compatibility of airport operations with the adiacent
land uses and then take actions to achieve a. iargci. rtcasurc c.f ccspaLi1: i"1 "-"
through reduction in the noise effective size of the airport is an important
element in the total program to reduce airport-community conflicts. Deci-
sions on runway alignment, airport expansion and volume and type of aircraft
use are as essential to ameliorating and preventing noise conflicts as are
the control of noise at the source and the control and guidance of land use
development in the airport environs.
It is understood that the FAA has the authority for requiring airport cer-
tification under existing legislation. That agency should therefore be
encouraged to take the necessary action to meet the EPA compliance schedule.
3. Continuing Program for Noise Abatement
We would concur in the need for & continuing Federal Program to assist in
implementing a comprehensive national aircraft/airport noise abatement pro-
gram. We would be happy to participate in those aspects o£ the program which
are cf interest and concern to the. Department.
OTHER RELATED ISSUES
There are other problems that need to addressed to further goals of the air
craft/airport noise abatement program; some of these are:
-------
-4-
1. National Airport System Planning
A National Airport System Plan appears to offer a key to the problem of
location and expansion of airports in the Nation, and a meaningful docu-
ment can lessen the potentially adverse impacts of such development.
The long range plan could identify the projected kinds and volume of oper-
ations at specific classes of airports so that there would not continue to
be the many surprises which appear to develop fairly regularly following
the creation of an airport or changes in operations at existing airports.
Communities in the airport environs would then have an explicit idea of
the kinds of airport development expected and could plan accordingly.
The National Airports System Plan should have a rational national focus
and not be only a compilation of airport projects conceived solely by
state and local authorities.
2. Modification of Airport and Airway Development Act (AADA)
We believe that the AADA can be strengthened to insure a greater measure
of compatibility between airports and their surrounding areas, as follows:
a) Aircraft noise is not specifically addressed in the law.
In view of the growing concern with environmental quality
and the impact of the airport development program, noise
merits specific recognition, The law does not now support
the acquisition of land to be exposed to severe levels of
noisejconsideration should therefore be given to modifying
the statute to allow the acquisition of such land, by ease-
men c or ree simple, as part of the ai'-nnrt- Hevelopment n-o-
ject costs. Inclusion of such a provision to cover areas
of very severe noise exposure is both desirable and necessary
to any meaningful solution to the noise problem.
b) The rules promulgated by the FAA for implementing the Planning
Grant Program under the AADA are not consistent with Section II
of the Act. Airport systems planning should be an integral
part of multi-modal transportation planning for the metropolitan
area, and should be handled by the appropriate public comprehensive
planning agency. Environmental considerations and airport loca-
tion should be a significant part of the systems planning process
rather than a token after-the-fact issue in airport master planning.
MCE
6/21/73
H-57
-------
May 18, 1973
Dr. Henning Von Gierke
Chairman, Task Group 3
6570 AMRL (BB)
Wright Pattersen AFB
Ohio
Dear Henning:
I have reviewed the Task Group 3 report and endorsed it
fully. It was a rewarding experience to serve on your task
group, and I feel confident that this effort will be a vital
part of the program to control airport/aircraft noise.
To help with the final chapter report, I have annotated
the pages of the draft report with specific comments. I
regret that time did not permit me to go through the appendices
in greater detail and make comments.
In addition to the comments made during the May 11 meeting
with the other members of the Task Group, I am listing below
some general points dealing with the report and the overall
conclusions and recommendations.
1. The overall approach taken in the report to develop
the cumulative noise exposure descriptor is good,
and Ldn is an excellent method for characterizing
this.
2. I fully support the maximum exposure level of 80 and
the future goal level of 60. The report contains
sufficient data to support these exposure levels.
3» While the conclusions are clearly spelled out and
appropriate, they are long. Many of the supporting
details are contained in the body of the repor' and
need not be presented in the conclusions.
^. Conclusions should state that the Ldn lends itself
to contouring in the same way that NEF does.
H-58
-------
- 2 -
5« Establish a simple basis for comparison between Ldn
and CNR, CNEL, NEf etc. This could be in the form
of a table, graph, or nomograph.
I trust that my comments will be of help to you and I
look forward to working with you further.
Best regards,
Robert S. Bennin
Director, Bureau of
Noise Abatement
City of New -York
Enclosure
H-59
-------
GENERAL CDUWSEv. OF THE SEPAttTJV-'EWT 51? CO
-i.Ton, D C 'OJ'30
.till '! Q :q?3
4» W U. J. * : *s I J
Mr. John C. Schetti.no
Director, Aircraft/Airport Noise study
Office, of Noise Control Programs
United States Environmental Protection A^oucy
Washington, D. C. 20460
Dear Mr, Schettino:
This is in reply to your request for the views of tlus ;»:. parL merit
concerning the Environmental Protection Agency Aircraft/Aj.rpovL
Noise Report Study, 1 June 1973.
This study has been submitted for interagency . "riew ir- draft f:err-
and organized into six Task Group reports. The. study was undort;:ki-:n
pursuant to the legislative directive in section 7(a) ; : !-lu> Jic-l.-e
Concroi Act of 1972 (Public Law 92-574). The Acl: clivifc^l.- the
Administrator to conduct a study of the
(1) adequacy of Federal Aviation \dniinist;.r;:i:ion IfV-^lit: ;ind
operational noise controls;
(2) adequacy of noise emission standards on new .i-u existing
aircraft, together with recommendations o;i the re.trof5.i:tiug and
phaseout of existing aircraft;
(3) implications of identifying and achieving iov-.'.s o^ cumu-
lative noise exposure around airports; and
(4) additional measures available to airport oper.'icors and
local governments to control aircraft noise.
The functions of the six task groups vj.re as follows;
(1) Consider legal and institutional aspe.oi:s of ai.iccaft and
airport noise and the apportionment of authority between 'h-'dcral,
state and local, governments.,
(2) Consider aircraft and airport operation.-; i.;.;c-.i.uc' i \gy
nonitoring, enforcement, safety, and co^ts.
*.S) CcTi-Liler the characterixutioi- of the impact uf a.-..rport
; -jv.-uui'Zy i:oii;-j. and to develop a ^umuluti.ve noise expooure measure.
H-60
-------
(4) Identify noise source abatement technology, including
retrofit, and to conduct cost analyses.
(5) Review and analyze piasent and planned FAA noise regulatory
actions and their consequences regarding aircraft and airport
operations.
(6) Consider military aircraft and airport noise and oppor-
tunities for reduction of such noise without inhibition of military
missions.
In order to assure that each task group report received the technical
review appropriate, the reports were distributed throughout the
Department for comment. The comments which follow are therefore
prepared separately and in relation to individual reports.
Departmental Comment
The Department of Commerce has serious reservations about the
adequacy of this study as a basis for aircraft/airport noise
regulations.
In general, we would stress that as these reports will be used
ar, the basis for EPA's initial proposed regulations of aircraft
noise and sonic boom whicli proposed regulations EPA will submit to
the FAA, we find the economic cost/benefit analysis extremely
inadequate and strongly urge that a more detailed and technical
analysis be untie rtakcn prior to the development of the initial regu-
lations. Specifically, we question whether the costs of compliance
have been adequately weighed and whether the technological feasibility
has been accurately measured, taking into account adequate safety
factors.
We note alc.o that section 7(b) of the Noise. Control Act of 1972
requires EPA LO submit such regulations "as EPA deterrriin.es is
£££££sai'y_ to p 10tect: flic pub 15.c health and welfare.'' (linphasis
added). This study docs not deal directly with the subject of public
3iealf.li and welfare. Therefore, EPA still must establish that there
is a need to protect public health and welfare from aircraft/airport
noise. Only aftc.r having established that need, can EPA begin
quantifying t:hr. amounts of. noise reduction necessary to meat the
health and welfare requirements.
T.'fsk Group I - Legal and Institutional Analysis o£ Aircraft and
Airport Noise rtud Apportionment of Authority Between
Federal, State and Local Governments
C o. noraj. Coii imon t s
Th<; Task G'oup v.v.i. clicrgeu. w:Li:l. 'ciiG following task.-.;:
H-61
-------
3.
1. Clearly settlm; forth t\;j existing liv.al./ijis: i '.utional
framework for aircraf t /airport noise control, includir-- all levels
of government .
2. Identifying constraints and shortcomings of the existing
legal/institutional system that r.\ay be impeding the implementation
of available solutions.
3. Making recommendations for structuring of legal/institution;'. 1
changes thai: would facilitate an accelerated and comprehensive
solution of the aircraft/airport noise problem, both by actions
within existing authorities and through legislative changer;.
It' would appear that the Task Group did a commendable and
thorough job in tasks 1 and 2 above. It is obvious that in an area
which impacts a major industry in several different vr-ays, any recom-
mendations tendered, i.e., task 3 above, vill be controversial,
however, the approach of the Task Group appears to be. both workman-
like and well reasoned.
Spec i fie Ceir.'nen'is
1. Criterion I: Pr oi'-.o t c Ad eg u a 1: e._Co n sj jj e r r. ' : j . on of A 1 1 Relevant.
Fac t: ovr; ; 1- a c t o r s to be Considered, :/]. Hfi'ects of Noire, on
Ful.'] :i. c >io alth and V.'elfarc. p._l-3-2
All the. factors listed in snbpoint (a) - direct henlth and
welfare effects of noise - and sub-point (b) - economic :iuu social
impacts of noise - are. negative ones. If the. only effects to be
considered are. d&trinumtal ones then obviously any conclusions rcr.eiii.-i
will be negative.
It is our contention, and it has been generally rcroj-.nizecl, the1/;
"public health" is ID.-. vite-J. to physical and rental wcll-boing, while
"public welfare" encompasses an extremely broad range of factors.
In relation to aircraft/airport noise, consideration of ''public
welfare" should include such factors as the economic benefits to our
nation, its individuals, and business, of air transport: and of air-
craft manufacture. It. should also include, the convenience to
individuals of air transport and local airport.1;, and flu: economic
advantage that location near an airport provides a town in attracting.
industry .
Factors such as those listed above should be, included in the lis
of examples parenthesized in l(b) so that a valid consideration and
balancing of the effects of noise on "public welfare" can be reached.
H-62
-------
2. Comparison of the Present Legal/Institutional Scheme With
Identified Criteria, p. 1-4-2
In its discussion of this matter, tht Task Group points out that
prior to the adoption of the Noise Control Act of 1972 amendment,
§611 of the Federal Aviation Act did not contain the words "public
health and welfare", but rather was aimed at. providing, relief from
"unnecessary noise", which according to the Task Group, suggests
"a focus on the issue of what level of noise can be abated in an
economically reasonable and technologically practicable manner," The
Tar;k Group Report continue;; "TTThe 1968 Act did not explicitly require
a consideration or balancing of the demands of public health and wel-
fare for a quieter environment on the one hand versus the economic and
technological feasibility of instituting abatement measures on the
other."
The implication of this language, coupled with material which
follows it on. the next few pages of the Report, is that the Noise Con-
tiro 1 Act docs require such a balancing of demands. We would vigorously
disagree with the. underlying assumption that "public welfare" is some-
thing separate and apart from economic and technological factors. We
refer to our px-evious discussion (point 1) of "public, welfare" aiu!
strongly urge this portion of the Report and any others wherein this
inaccurate iissumption appears, be redrafted. The concept of public
welfare is irt itself a balanced concept - to arrive at a definition
ol public welfare it is necessary to balance both beneficial and
detrimental factors oi. the subject, matter- under coasidoration.
-> /li-'-Pj.ict'uj.011 of Koisc Regulation.? fro Foreign Aircraft:
Roc_o:,:.-:>£j-i_d_at .unT_ #5, p. I-6-12
lue v~-c. ..rn!!=c nd.'». 1 . ;:..o:i provider that:
". , , i r ,'.' TL- ommeiiuiid !..ua;: all U.S, regulations regarding
airct-nj i noise be api-.1xed e.qually to all aircraft., operating
into 'u'.J'r. .lirpo?. Ls. Yi'ii." includes ru3.::3 of airport propri-
etors adopted pursuant to achievement of their, implementation
pL-ins uncJor the p;:of^.,:"J ai.rporf; no:L5 n r^julatior.,
"iV'sxi,:d;.-.-.(: the uc.aig;-i c-l: Aircraft hardware, when adcu.uate
i ntornai.";.on?al "tr.ndards are established (e.g.. a for re frc.f ?!.!:..,
fl-'v-i: ]:'..,';> level or type certification) which are o^ruilar
r:o or v?)1 ;.']) b':ve '-.:ub.<;f",'1,-il:.i;3 J.ly equivalent. ef.'"ect ':.: \1 ,S,
rc-u) il:i :-.in: -, ;.. .:. ; .-coders;ndc_d_ that the llllit£l.J^.t:tj^ _V;^J^
comnl i .-.; - cc v;icii j.rs rult: f'o the exter.i:
i'H:!)l' ^''..'-"J'J_'2 th(> ;i r,f:c:;;a; MIrta 1 s 1:-:tndard. TEris is provided
i:oroi;',n j,overni:ii.'iit.s Kinilarly vjaivc compliance with t.]/:.ir
nol'j;- KI..-:-.-..-;!^-,.:!^ 'fir 1;US. ovr.icd .i.i.rcraft ':hat comply with a,i
oqii-i.vc:] ont Ar!'r::--.in -.- ;>-.:! af ion. The purpose is t:o provide
c<1' !'" ''';. . ?.'!' '.-(t' i- i.-..'i^T:ij.-r^.t ;ne^..^'roiTie;it {::..: ecurui..
i.;" '"i:.:". .;'>. i'c.,... :.;.- i:. ;;.,:i..-.v.;iii' ial Ly ;;nchaiigaj ':l.c:r.:by ,!V
-------
We strongly endorse this recommendation.
Any exemption for foreign aircraft would have the effect of
imposing a cost penalty upon United States air carriers engaged in
international traffic. This would seriously affect the nation's
carriers' ability to compete with their foreign competition carriers
and impose a non-tariff trade barrier on this important industry
which is already in an extremely precarious financial state.
Furthermore, any aircraft/airport noise regulations which are
eventually promulgated would be effectively impeded in their ability
to protect public health and welfare if foreign aircraft need not
comply with those or equivalent noise standards.
Task Group II - Operations Analysis Including Monitoring,
Enf orce.raent, Safety, and Costs
Hajor Comments
1. The report is written clearly and is organized well. Its
conclusions are explicitly attributed (p. II-v) to the EPA rather
than to the task group par sc, though the title page could make this
clearer.
2. The text gives both slues of points in dispute. This is
not quite as true in the sections on Conclusions (II-5) and
Recommendations (II-6), which inny be the only sections that people
will examine. These sections should therefore refer the reader to
the balanced discussion on II-4.
3. The Cost-^Ofsctiveness conclusion (p. II-5-3) requires an
assertion, nowhere made explicit, that the cost of noise is much
nearer to $100 (or more) per person, per year, than to $10. This
cost refers to persons in the "L^n = 65 area." So'crude nn approach
is clearly suspect--if a noise reduction procedure shifi Mr. A from
the L
-------
4. Yet ano'dier difficulty is that the noise measurer employed
NEF) are largely of the nature of consensual artifacts; rather
than "derived quantitics"--they combine relevant factors, but the
mode of combination is sufficiently arbitrary that numerical manipu-
lation of these measures as indices of "noise impact" is always cause
for discomfort. This comment, and that in (3) above, docs not mean
that the Task Group could have been expected to invent significant
new methodology or to gather significant new data. But these comments
do point'up some of the multiple uncertainties in the cost-benefit
analysis, uncertainties which might have been more explicitly noted,
and also used as a reason for tempering the coiiclusion emerging from
that analysis.
5. The discussion of the effectiveness and necessity of
monitoring (pp. 11-3-12 ff.)j an^ the associated finding (p. 11-5-3,
top) are based on opinion and (necessarily imperfect) irecollection of
experience. We believe that experimentation on this topic is likely
to be fruitful, and should be considered. More generally, the thcmo
of planning to observe and learn from early efforts is disturbingly
absent.
6. Noise certification for airports, and grants to A/P's- of
related powers, arc very reasonable, but still leave open the question
of what criteria and policies the FAA will follow in deciding whether
or not to certify.
7. Principle #1 p., II-6-1. The Department v/ishes to state in
the strongest terms, its disapproval of this type of analysis. Firstly,
the whole purpose of this study is to arrive at some idea of the cost
and technological feasibility of controls and noise abatement pro-
cedures. Secondly, the.concept of public welfare demands a balancing
of the costs and benefits involved in reducing noise. Thirdly, it
should be evident to the most casual observer that many standards
imposed by the Clean Air Act have not proven either reasonable or
achievable and that the imposition of regulations without basis is
unworkable. Finally, while regulations based on achievable control
technology may in fact act as an impetus to new technological develop-
ments, new technology cannot be manufactured out of whole cloth in an
attempt to meet unreasonable regulations.
Technical Comments
1. Page 11-1-3, bottom: Text notes that "safety" is an elusive
judgcmonlal quantity. "Economic reasonableness," cited on the same
page, is even more difficult to assess.
2. Page 11-2-2, para. 3: This unexplained uniqueness of treat-
ment for National Airport will certainly strike the reader. If no
special effort was made to use this special situation as a test-bed
for information-gathering, that is a real pity.
H-65
-------
3. Pago TI-2-5, parn, 3: To-assert that an operation is safe,
ii_ done exactly right, evades the basic question.
4. Page II-P-S: Hear.ing of (10+)? Bottom of p. II-2-5 indicates
"near 10" rather than ">10" is intended. ?age 11-2-9, 2{a): to
10-)-MO.
5. Page 11-2-11, top panel: "Acclcrate" should be "Accelerate."
6. Page II-2-15, para. 3, line 9: WHO precon-.putes and transmits
this figure?
7. Page 11-2-17, para. 4, end: Close parentheses.
8. Page 11-2-26, para. 1, lines 3-4: Basis for estimate?
Para. 5, lines 3-5: A reference should be given for this appraisal,
say that of Figure 11-3-2.
9. Page 11-2-30: Prefer l:o see life-cycle costing of the
equipment.
10. Page H-2-31, psra. 2, lines 3-4: This should not be
dismissed out of l-.'nvj. The reader who sliPros this view could be
placated by a rti'ejrerice forward to the bottor.i of p. 11-4-7.
11. Page 11-2-34, para. 3: Text .<:ecms to be presuming quite a
lot.
12. Page 11-2-36, para. I, line 2: "It's" should be "its."
13. Page 11-3-4: This and Figures II-3-3, 4, 5 lack references.
14. Page IT.-3-5, para. 5, line 6: as a criterion.
15. Page 11-3-16, para. 3, lines 1-3: Evidence?
16. Page 11-4-6, option 2, line. ?- "eduction" should be "education."
17. Page l'J-4-7, end: Basi ?
IS. Page 11-6-2, Id: Recommend to whom?
Task Group 111 - ]iv;pact CF>oract< ri?,a 1:ion o_f^Noij;o_jfjicluding Imp 1 icationn
o.T_]dc_j^l:i.fyin^ and Achieving Levels _oi" Cuniulal.ive
K'oj.sc l'''\p(.'?:','rc
Si'I'Ll1'-"-I Co::;!uenl:.'-.
T'ae treatment of aircraft noise as but one component in the over-
all noise environment has been advocated by those at the National
H-66
-------
8
Bureau of Standards working with noise programs. The employment of a
weighted sound level measurement and the use of an "average sound
level" concept for cumulating noise exposures also appears quite
reasonable for the stated objective.
Task Group IV - Noise Source Abatement Technology and Cost Analysis
Including Retrofitting
Our comments on this Report are addressed only to Section IV-4.
An adequate review of Section IV-4 is not possible without also
reviewing several of the reference documents noted in th& text which
were not available to us. Therefore, we offer only a few general
comments and point out some specific points in tha Section that should
be. clarified and considerably strengthened before the document plays
a significant role in decisions on how and when to carry out noise
reduction programs that consume billions of dollars of the nation's
resources.
General Comments
Section IV-4 at best is no more than a beginning attempt at a
tentative identification of the costs and a few other variable's
involved in approaches to cope with aircraft and airport noise. As
an academic discussion of a pressing problem it is a contribution.
But it needs considerable shoring up before being used in making far-
reaching policy decisions.
While the document does give some estimates of costs and effec-
tivc.ne.ss, it provides no estimate of public benefits derived from, a
reduction in noise level and leaves many important cost questions
unanswered. For example, how much better off would mankind be with a
reduction of 45 to 40 on the NEF scale, or by protecting every person
exposed to Lc|n = 60 or greater? What financing has been developed?
How will the airlines, airports and communities raise the money to
pay for the various strategies and how will this likely affect other
desirable programs?
Spec.)'.fie Points
1. On page IV-4-1, the. document identifies the null strategy as
one in which, "no aircraft/airport noise reduction program is under-
taken." But on page IV-4-2, "the null case" is described as a
"do-nothing source treatment strategy" involving several "situations."
Of the. four situations listed and analysed, only the first, The Cost
of a Judicial Alternative, seems a really do-nothing strategy. The
other three are definite, positive action programs with significant
effect:; on the operations and costs of airlines and on communities and
the costs of airport operation. This conflict needs to be cleared up.
H-67
-------
2. At the. to;} r.,. paj^e .:.-q.-2, the <.; .-ueni. : . le.:!..:. periV;
j>"ilns thai "n;irht i'u; i'iK-r GJ.J'j^r r.ic.iic. of -;.. co^l -n'ld :::.ul; ,
modification oi the r::-1. LT.OS in oxis'..:ini?, nay. ,>v o;->i.L--J aircraft W
;iciv;i!!i'ed noise Vec iiiioior.y eiv.'lne.i; \.iert'.:i). i-.v.i; o-; ;)..;;:,e T »' '-, -'j 0 .
reference i? iiiacie Co :!pol entia L ic-~,c produc u ivil. v o:.. rot t:o< i i ;: -
wlvj.cli rou.Ui rosu.lt liroia clicint;,os iii r:^ j." i orniancc _, w...! fj',t, or i';;t:!.
conrAirtiption . " This raises the qiuv-tMi'.n "\\'ilL uv.: ' JT. <. IIIIHMI ; ai\-.
perform better or worse than their ^;\;.,cui:i;ieU i:ou;iLorp:irt:: V" Tii
doc.\u;icnt sliorld yivc an answor co r::.i.s questi.on.
3. Also on pap.c IV-4-2, the duc-.u;nent says tiiLs: "Tin.- sui':
text vill invc'.stigatn tha existence oi a deiinite iiiarkct inconur
move foivavd vitli an airport noise reduction pror,r<~m and dolinc-i
t!io potC'.ntial financial, economic, social, and cultural. ui?i.oca:,
that may result if a national noise reduction pro^.r^ni i..s n.:!^i.iii; .u-.'/or
to lie used to support important policy decisions. l.ndec.u, ;;i: L:
gation of "financial, economic, social, aiv.s ciilt-.'-ul '^.i.x [i.a-c .;>].
an ir:iportant part of any benefit ^.na Lysis wnich ,i ; -;o tot;i >.' - :
in Section 1V-4.
4. On pa<;c IV-4-15, the docuv:!C!i\!' ray;', .'.ii
be placed in three distinct categories raid f;ivofi : he CLr.-.t c.>-:e
"routine, planned traffic that could be dive.i-io.ci to surface, i.;;:;:
tion because ic is not perishable." The -de.^cr.LpL'..: on oi" tin':-: c;i ;
would be acceptable if it had stopped with "routine planned Crai.
But: tlie remaining modifj'ing phrase.?- ;;inice it extrerrclv mislcaciJP;-.
VJith average freight revenue, per tcn-r.iile of r.earJy 23 ce.nt?.; J c>"
and 8.2 and 1.6 cents, respectively, by true!-: and ;::;:._, j L vtiu i .:
be practical to ship by air, "traffic that could he riiveru'et! to
surface transportation". Scree traffic cannot be diverted t.o su;-
transport without inc.rea.sing total physical distr.; bi-trion cu:-;s,
that v.ioct likely is why the. shipper sends it by air in the. ! irri
This point is made as an illustration of the lack o;.' .reality au-.-.
in other analyses in this Section.
5. The document gives another c;\te;io;.y of ;:.i.r (\tr^,o ;.;.-; "c-:^
traffic which is unplanned and highly rir.ie. sensitive". Then or
p.an.e T.V-4-16, after no analysis au-:i alter p.ivinr, no i'acts,
eludes, "Therefore., a few hours' 'delay in must '..!;;:':'.-.-cncy'
result ]>ri!;:arily in ir.eonveniep.ee, not. spoi j.a;.-,e:'. \;-:. ;;ti;',^
i5>.l:ue d(^j;iands both more facts and ;..: r;- ar.nlysit;. M.i:/> :-:..!-
''eiiierj'.eiicy" air shipments are. ;nado. to .ue.ct partic e i :': :.'.ai-i:.
tirics. to repair expensive. equipraciiL, and to keo,'
.iclu'ciule.. Some-, emergency shipr.ient.s ai:e made to cave J.ive.;;. Thus
H-68
-------
10
few hours' delay could mean missed sales, excessive down-time, for
expensive equipment and machinery, disrupted production schedules -
all of which raise costs - and in some instances, possible loss of
life. These are the main reasons more analysis is needed.
6. A similar weakness in the document is indicated in item "6,"
at the. top of page IV-4-18. This item suggests that the only conse-
quence worth worrying about is loss of revenue to the airlines. We
suggest that at lcar:(r as important is the. impact on shippers and the
gevienl public., which the document hardly analyzes at all.
Tank Groups V - Review and Analysis of Present and Planned FAA Noise
Regulal'.oi'y Actions and Their Consequences Itafcarding
Aircraft and Airport Opo.rations
and
VI - Milivary Aircraft and Airport Noise and Opportunities
ft) r_ Reduction Without Inhi bit ion ol: Military Mission s
('.en e_ra 1 _C£W:T>O nt s
We would highlight the following points:
1. It is estimated that the system cost to implement the. Task
Groups' recom!nonda.';ions would total $31.0 - $42.0 billion. This
figure is bcv.;:-. i dov?n as follows: $21 - $31.5 billion for charges
in land use, $6.0 million for aircraft engine retrofitting,
$691.0 in-i.l ).-i.i>n remitting from imposition of flight curfews, and
$117.0 -.iiillJ. on -hie to changing of aircraft operating procedures neces-
sary to ;r.:!'iio.v--- a reduction in community noise levels.
:'.;ry wuli bo beyond the financing capability of the.
.jvincion i no-.i^try. Forecasts of airline traffic indicate that it will
continue tn expand nt a high rate and the airline industry will need
to {spend niorr- than $27 billion during this decade lor new aircraft: and
related ground oc|uip:ncnt. The--, industry will need to raise those fund.1-
primarily tiiroujr.Ii additional equity and deb;; since preseni: i'uid
projec r.iul ic.-vei.ri of: eaming.s will not provide sufficient capital.
Aiircra f.t iiiasiu'.'.ictiitcrs face a similar problem in obtaining fch" dovflop-
ri'iMil". Juiiti:-; ro.,]u:i red to produce, "ecologically conscious" aircraft and
c'-iig.) iiof, '.:,).!!.' i-.iif.i.r high debi:/oquity ratic^ make?; it pracl:ical Ly
.linpor.sibL: to ai.t.v.-ict outside investment capital.
'}, The .vukk-.d co.,';. oi the proposed regulations-, v;hich v.iay or
>:'.ay w>\\ C'.chi-.-\\i n ix-al reducti.oji in noise under coviditions of flight
::'..r-.'i:y nr.e! vv^j'-cj'ii i o vr-ri'^riv-.iiicr . will be prohibitive i.'or the*, industry
'.,, nii-M-.it., 'j'iiv-.r.- '.-O--T.S, o! $.''.1,0 !:c $42.0 bi'U.ion, whc-7) acldoM tc
:.!;-: ri''- :<->..' ' . y :: -^-^ '^\1 '' 27 b -' i ! ion -:n ;:icet 'k'vnand. i:of-:';.. ;>:;
^ ';'>1' I-..'.'.!.: --.1. /-i-J.. :: :;:-<;.-''!. c;;':ond iturc 3
T-f-GV
-------
11
$7 billl.':'. yearly v;hlch ::.. r -ent5
j.nih;:-:!' ry ..ilh :i i. ale ol r- i . . . o ."
>:h, C.':;: ;:= "a fair ar.i r^asr -... !; ;.c!
than hai J !'::''. : , ;. .. LI o-.i !v
j. . The r^por!:s rej^rL-f-^ii; th
not: tr\-]y "cor.;.' P..SUSM rcoori ^ .is
2. The reports do not prrsr.
o:" the ::h:rj.-r:'.rv -."i1 >-'-
3. Tliere is an absence of an cK'p.(;i-.-'.i;:o fuVjOj- '. -.:i.o!' o :' ';; v a .'.
a'.nnunt or work or; those ;'ulvjoof: s in L.'ic.1 ".::-1: fio-:'.ac\- , r:a:/r c-p ;.b ;
C;. '.V:>
iTie.nden c])c:cific r.ccoptablc levels.
6. There is; no aereo'nc^L, support.;;: ry .:::ca::', ro(",
report or thai: c-V: h.h, of 80 DMA is Lha ;..-.".rov;r:i afo l:l.n:i
7. The.re :! '". no r.d(K;oal a bn
i::i:i t s; for ''nealf.h aiid v.'ol.fai'o"
8. i.'iiiUiavrv ;'io?ir.(> inOn^cviiii'
9, It K?A should announce a i>L-a'!i'i: i'
ocnT'o I'C-coi.io t}\;- b.:s:uf for o.vi'i ol a.r.;:-:; To
i.ii'! i::; i :r- ;"rorn ;:'J..!. s01 Tc<. s of no 1 sc ,
H-70
-------
12
ill. A iv.i::-!>i'r of re.co.!;-n.-.Delations of: Ta.sk Group II involve- ;j
moiit.r i)--; flit: sa'i-ty nsiiccl;.': oi: aviation. This ia an area oil FAA
cxpfrJ..i.':c rind :j!".;i:ld not bo flssinuc-.d by KPA or its Tasic Groups.
/ _
,.. Ansi.'ju'in;: G-iii^v.i Counsel
lor L (..-p, is Lai::.', oil
-------
3855 iaAewood Boulevard Long Beach, California 90801
Cl-25-3787
June 29, 1973
Mr. Henning von Gierke
Chai m-.n, Task Group 3
Offict of Noise Abatement and Control
Environmental Protection Agency
Crystal Mall Building 2
1921 Jefferson Davis Highway
Arlington, Virginia 20460
Dear Henning:
We have reviewed the June 1, 1973 draft report of Task Group 3.
Attached are a number of comments both relative to the report
and relative to the operations of the task groups.
We appreciate the opportunity to have participated in the activities
of the task group and also the opportunity to have our comme nts in-
cluded in the final report.
There is a tremendous amount of data in this report and the time
available to review it has been short. We may well have overlooked
some key elements of the report on which we should have preferred
to comment. Under these circumstances, failure to raise objec-
tions to any particular element of the report should not necessarily
be construed as an endorsement.
We will take this opportunity to compliment you on having performed
a minor miracle in getting this report together considering the
complexities of the aircraft noise problem, the widely diverse views
of those involved in the problem and the very short time that was
available.
Very truly yours,
A. -L. McPike
Di rector
Industry Association Activities
ALM:ab
att.
coafonartoiv
-------
Attachment to:
Cl-25-3787
June 29, 1973
COMMENTS ON DRAFT REPORT FOR TASK GROUP 3
1. We agree that it is vital to establish a consistent basis for evaluating com-
munity response to noise. We cannot disagree with the selected concept of
a yearly average cumulative noise exposure level. We endorse the concept
of evaluating the impact of aircraft/airport operations using an equivalent
noise lavel measured at the location of the listener. We support the choice of
A-weighted sound pressure level, in dB, as the preferred noise measurement
quantity.
2. The draft does not discuss the issue of the possible adaptation of people to
noise. Evidence available to us indicates that some people do adapt to high
noise levels over a period of time and that this adaptation affects their response.
We feel that the report should discuss the changes in response that occur due
to adaptation.
3. We support most of the conclusions and recommendations. We are not con-
vinced, however, by the material presented in the draft that appropriate
choices have been made for maximum permissible cumulative noise exposure
levels (outdoor day-night average sound levels).
4. The information on speech interference does not seem to be applicable here.
If an L , of 60 dB was the result of an unvarying background noise level,
then the concept might be applicable. In the case of aircraft noise, however,
there are many noise peaks during which-speech communications can be
difficult or impossible. The average speech interference level would probably
still be such that speech communications would primarily be rated as accept-
able.
5. The selection of L , = 60 dB as a long range goal from the viewpoint of annoy-
ance seems to be completely arbitrary. On the one hand, it seems questionable
to accept a long range goal that admits nearly one out of every four people
will be highly annoyed by noise. On the other hand, the level selected leads
to such large impact areas around airports that practical considerations will
probably rule out-ever achieving the goal.
H-73
-------
\ttachment to:
Cl-25-3787
June 29, 1973
- 2 - Task Group 3
6. Correlating the data in the report dealing with percent people annoyed and
with the number of people exposed to various L , levels indicates that
about 70 percent of the highly annoyed people reside outside the L , 70 zone
and that only about 2 percent of the highly annoyed people are inside the L,
80 zone. If this interpretation is correct, we obviously do more good for
more people by minimizing the noise of aircraft farther out rather than quite
close to the airport. However, by implying that large areas around airports
are completely unacceptable will ensure against the general acceptance of
the concept. Therefore, it is urged that the recommendation for the 60 dB
long range goal be coupled with recognition of the practical problems and
great costs involved in achieving the goal.
7. We concur with, and support, the position presented in the letter submitted
by the Aerospace Industries Association relative to the Task Groups operations
and reports.
H-74
-------
APPENDIX I
LIST OF REFERENCES AND MATERIAL NOT PROVIDED
IN THIS DOCUMENT. THIS MATERIAL IS AVAILABLE
IN THE PERMANENT FILES OF TASK GROUP #3.
Mailing list for TG3.
Letter from Robin Gegauff, dated March 2, 1973, concerning noise from operations
at Boston-Logan. EPA reply dated March 12.
Draft text on "Noise Exposure Units, " dated 26 February 1973.
Report of World Health Organization on "Urban and Occupational Noise" (WHO/OH/
73.12) dated 13-17 Dec 1971.
"House Noise Reduction Measurements for Use in Studies of Aircraft Flyover Noise".
SAE, Inc., document AIR1081, October 1971.
Testimony of Mayor Merle Mergell, Inglewood, California, presented to the Aviation
Subcommittee of the United States Senate Commerce Committee, March 30, 1973.
Comments of the Honorable Mario Biaggi to the U. S. House of Representatives,
28 Feb 1973, published in the Congressional Record, March 1, 1973, page E1149.
Draft Text on "The Meaning of the 'Public Health and Welfare' Pursuant to the Noise
Control Act of 1972" by Richard Rice, 23 March 1973.
Letter from Ruth and Walter O. Bahler, dated 26 April 73, concerning noise and
safety problems of "touch and go" training operations of Moffett Field. Also letter
reply from Task Group 1 chairman, dated 4 May 1973.
Letter from Randolph Subregion Community Council dated 16 April 73 and letter reply
from John Schettino, Director, Aircraft/Airport Noise Study, dated 4 May 1973.
Report of the Aviation Advisory Committee, 3 January 1973.
"A Preliminary NASA Report to the Environmental Protection Agency for the Aircraft/
Airport Noise Study, " February 28, 1973. (Chapters include Impact Characterization
Analysis, Source Abatement Technology, Operating Procedures, Military Aspects.)
Integrated Noise Exposure and Its Relationship to Other Noise Measures.
1-1
-------
"A Summary oi' Two Community Surveys on the Effaces of Aircraft Noise" by D. M.
Zamarin, L,E. Langdon and R. 7-'. Gabriel. BRAD Fo^u Report No- A1DC J5033,
March 1971,
"Aircraft Noise and the Community: Some Recent Survey Findings: by A. A, Burrows
and D. M. Zamarin, Douglas Aircraft Co. Paper 589!, 26 April 1971.
"The Effect of Aircraft Noivse Exposure Variables on Television Viewers''' by 1.. E.
Langdon, Jr., R. F. Gabriel, and L.R. Creamer, Douglas Aircraft Co., Report No.
MDC J5605, June 1072.
"Investigation of DC-S Nacelle Modifications to Reduce Fan-Compressor NTnise in
Airport Communities, "by L. E. I.angdon, R. F. Gabriel and A. H. Marsh. NASA
Report No. CR-1710, Dec 70.
Paper on "Hearing Loss Expected for Various Noise Exposure Values" prepared by
Daniel L. Johnson. AMRL (EPA).
Paper titled "Percent of the Time that Speech Interference Will Occur ior Various
Lcq Valuers" prepared by Daniel L, Johnson, AMRL (KPA).
Addendum No. 1 to "Percentage of Time Speech interference Will Occur For Various
Leq Values" by Daniel L. Johnson, AMRL (EPA), dated 26 April I37:u
Addendum No. 1. to "Hearing Loss Expected For Various Noise Expo:-arc- (ME) Values:"
by Daniel L. Johnson, AMRL (EPA), dated 26 April 1973.
Memo from Dr. Lawrence A. Plumlee, M. D,, of EPA Office of Research and Monitor-
ing, dtd February 22, 1973, concerning noise of pc-'ice helicopters. ONAC r^ply did
March 10.
Letter from M. P. Kelly of Opa-Locka. Florida, concerning noise from Opa-Locka
Airport, dtd February 12, 1973. EPA reply dtd March 13, 1973.
NASAO letter dated March 1G, 1973, stating their position regarding nec-d for develop-
ment of a uniform state law covering land use control around airports, and need for
Federal guidelines.
"A Proposed System for Aviation Noise Measurement ;">nd Control, " by iv \V. Simpson
and A. P. Hays, FTL Report R73-2, dtd January 1073, Massachusetts inst.. of
Technology.
Letter from John S. Moore, Division of Noise Po'ilu'iion Control, Illinois Environment.;!]
Protection Agency, dated 20 June 1973.
Letter dated ;() May 1973 from William Becker of -.h-j Air Tr;>:ipporl .l.i-:.-..-c''a(i'yr,.
Subject: Commonis Regarding Draft Report of E1*A Task Group 3.
Letter from Al Me Pike, Douglas Aircraft Company. Subject: Comments Regarding
Draft Report of EPA Task Group 3.
1-2
-------
Letter dated 18 May 1973 from Robert S. Bennin, Director, Bureau of Noise Abate-
ment, City of New York.
Letter dated 22 May 1973 from Harvey H. Hubbard, Head, Acoustics Branch, Langley
Research Center, NASA.
Letter dated 24 May 1973 from Boeing Commercial Aircraft Company.
1-3
-------
GLOSSARY FOR NOISE MEASURES
sound pressure level - In decibels, 20 times the logarithm to the base ten of the ratio
of a sound pressure to the reference sound pressure of 20 micro pascals (20 micro
newtons per square meter). In the absence of any modifier, the level is understood
to be that of a mean-square pressure.
sound level - The quantity in decibels measured by a sound level meter satisfying the
requirements of American National Standards Specification for Sound Level Meters
SI. 4-1971. Sound level is the frequency-weighted sound pressure level obtained with
the standardized dynamic characteristic "fast" or "slow" and weighting A, B, or C;
unless indicated otherwise, the A-weighting is understood. The unit of any sound
level is the decibel, having the unit symbol dB.
average sound level - the level of a constant sound which, in a given situation and
time period, has the same sound energy as does a time-varying sound. The average
sound level is also called the equivalent sound level. Technically, the average or
equivalent sound level is the level of the time-weighted, mean square, A-weighted
sound pressure. The time interval over which the average is taken should always
be specified.
sound exposure level - the level of sound accumulated over a given time interval or
event. Technically, the sound exposure level is the level of the time-integrated
mean square A-weighted sound for a stated time interval or event, with a reference
time of one Second.
L time-varying noise level
L A-weighted sound level
J\
L, "background" or "residual" sound level, A-weighted
GLOSSARY-1
-------
L , daytime average A-weighted sound level between the hours of 0700 and
2200.
L Sound exposure level - the level of sound accumulated during a given event.
\^r
L day-night average sound level - the 24 hour A-weighted equivalent sound
level, with a 10 decibel penalty applied to nighttime levels.
L average, or equivalent A-weighted sound level over a given time interval.
eq
L hourly average A-\veightcd sound level
L nighttime average A-weighted sound level between the hours of 2200 and
n 0700.
L maximum A-weighted sound level for a given lime interval or event
max & to
L x-percent sound level, the A-weighted sound level equalled or exceeded
x % of five
AL difference in decibels between two different A-weighted sound levels
------- |