Umtecf Sum
Emuonnwnul Prot»clion
Oli.w of
NOIM Abatement
OKI Control
EPA 550/9 B0100
.»"»» 1980
NO.W
-------
TECHNICAL REPORT DATA
(nfatt rtea Instructions on iht reverse ttefort complennyl
I. REPORT MO.
550/9-80-100
0. HECIPI8NT-S ACCESSION NO.
139973
«. TITLE ANO 8OBTITL8
Effects of Noisa on Wildlife and Other Animals
Review of Research Since 1971
S. REPORT OATS
S. PERFORMING ORGANIZATION CODE
7. AUTHQRISI
Patricia A. Dufour
3. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION HAMS />MO ADDRESS
InfontBtics, Inc.
6011 Executive Blvd.
Ftodcville, MD 20852
1O. PROGRAM ELEMENT NO.
II. CONTRACT/C-HANT NO.
IX SPONSORING AGf NGY NAM8 ANO ADDRESS
U.S. Environmental Protection Agency
Office of Noise Abatement and Control
401 M Street, S.W. (MR 471)
Washington, D.C. 20460
13. TVPE OP REPORT ANO PERIOD COVERED
14. SPONSORING AGENCY COOE
10. SUPPLEMENTARY NOTES
The Reoort is based in part or. a_preliminary reoort prepared by. John L. Fletcher, Ph.'D.,
iv>ivm>"«!-n-y of Tennessee Center for Health Sciences, Memphis, TN 38163
1
-------
Effects of Noise on Wildlife and Other Animals
Review of Research since 1971
Thi« report ha been approved for general availability. The contents of this
report roftect the vi?ws of (he contractors, who are responsible for the fact)
and the accuracy nf [to data presented, and do not necessarily reflect
the official vietv» or policy of EPA.
PERMISSION IS GRANTED TO REPRODUCE THIS MATERIAL WITHOUT FURTHER CLEARANCE
-------
The following report is a survey of research on the effects of noise on
wildlife and other animals. It was produced in response to a large number of
requests for information en this topic, and to address requirements of the
Noise Control Act of 1972, as amended by the Quiet CQmr.vjnities Act of 1978.
No quantitative criteria are proposed in this document, largely because
the body of research on any given question is not sufficient to support the
establishment of criteria. More research is needed before quantified dose-
response relationships can'be determined.
Although the report does not attempt to identify levels of noise which
will protect animals from adverse noise effects (as has been done for humans),
it does provide important information for Federal, State and local officials,
researchers, environmental and conservation organizations, and concerned Indi-
viduals. Among other uses, it is intended to assist in developing Environ-
mental Impact Statements on projects affecting animal environments.
iii
-------
TABLE OF CONTENTS
PAGE
PREFACEl .............................. -. ............................ • 111
TABLE OF CONTENTS ............................................. v
USTOFTABLES ................................. . ................. v11
LIST OF FIGURES ................................................
INTRODUCTION .................................................. l
History, Scope and Intended Readership ............................. 1
Organization of this Report ....................................... 2
Overview of Effects of Noise ...................................... 2
Primary and Secondary Effects ... .............. ................. - 2
Heari ng ................ < ....................................... 3
Maski ng [[[ ... - 3
Nosauditory Physiological Effects .............................. 3
Behavioral Effects ............................................. 3
SECTION L .LABORATORY ANIMALS ......................... 5
Introduction [[[ 5
Heari ng [[[ 6
Nonauditory Physiological Effects ..... ......... .... ..... . ......... 8
Cardi ovascul ar Effects ......................................... 9
Neuroendocri ne Effects ....................................... .. 9
Biochemical Parameters ......................................... 13
Pulmonary Effects .............................................. 14
Resistance to Disease .......................................... 14
Audiogenic Seizure Susceptibility .............................. 15
Reproductive Effects ........................................... 16
Behavioral Effects ................................. ' ............... 18
Summary [[[ . ....... 19
SECTION H. DOMESTIC ANIMALS ............................. 21
I ntroduction ..................... ..<> .............................. 21
Heari ng ................................................ ; .......... 21
Physiological and Behavioral Effects in Farm Animals .............. 25
Swi ne [[[ 25
Cattle [[[ 26
Sheep [[[ 27
Horses ................ . ................................... . ---- 33
Mink ........................................... -, ...... .. ....... 34
Poultry ................. - ...................................... 34
-------
PAGE
Nonaudltory Physiological Effects 45
Behavioral Effects 48
Summary 52
Birds 53
Hear 1ng 53
Masking f 53
Nonauditory Physiological Effects 54
Behavioral Effects 54
Summary 57
Reptl 1 es 57
Hearing 57
Amphibians « 58
Hearing 58
Behavioral Effects 59
Fish 59
Hearing ,,. 59
Maski ng , 61
Nonauditory Physiological Effects 64
Behavioral Effects 64
Summary 67
Insects 68
Hearing 68
Nonauditory Physiological Effects 68
Behavioral Effects 69
Summary 70
SECTION IV. SUMMARY AND SUGGESTIONS'
FOR RESEARCH 71
Summary 71
Hearing 71
Masking : 72
Nonauditory Physiological Effects 72
Behavioral Effects 72
Suggestions for Research 76
APPENDIX: NOISE AS A STHESSOR ' 79
BIBLIOGRAPHY 85
v1
-------
V TC"TTI /"TiTT? HP A TTBT TT7C!
LIST OF TABLES
PAGE
1. Hypothetical Examples of Primary and Secondary Effects 2
2. Mean Auditory Thresholds 1n Decibals 23
«
3. Effect of Sound Type and Intensity on Lomb Heart
and Respiration Rates 28
4. Hearing Abilities (Frequencies) of Various Animals
as Compared with Man 38
5. Estimated Sound Detection Distances under Different Ocean
Noise Conditions for the Harbor Seal, Phoca vitulina 47
6. Estimated Sound Detection Distances of Four Marine Fish
Due to Different Sea States and Ship Traffic Levels 65
7. Nonauditory Effects of Noise 73
vii
-------
PAGE
1. Auditory Threshold for Sheep 22
2. Audiogram for Cattle and Sheep 24
*
3. Heart Rates of Lambs Exposed to Different Sound Types
and Intensities 29
4. Respiration Rates of Lambs Exposed to Different
Sound Types and Intensities 30
5. Average Daily Gains of Early-weaned Lambs
Exposed to Different Sound Types 31
6. Average Daily Gain of Early-weaned Lambs Exposed
for 12-Day Periods to Different Sound Intensities 32
7. Frequency Spectra of Background Noises and Off-Road
Vehicle (ORV) Noise in an Australian Habitac 40
«
8. Shallow Water (<70m) Ambient Noise 43
9. High Frequency Ambient Noise and its Probable Masking
Effect on the Hearing Abilities of Selected Marine Animal* 46
10. A Comparison of Hearing Curves among Selected Fishes,
Marine Mammals, and Man 60
11. Low Frequency Ambient Noise and its Probable Masking
Effect on the Hearing Abilities of Selected Marine Fishes 62
12. Low "requency Ambient Noise and Its Probable Masking
Effect on on the Hearing Abilities of Selected Marine
Fishes (Second Group) . - 63
13. Effects of Sustained Noise on Egg Mortality ar.d Fry
Survival and Growth in Two Species of Estuarine Fishes 66
14. Impact Assessment Steps 77
A. Impact Assessment Steps 81
••
8. Stress Responses .* 83
viii
-------
HISTORY, SCOPE AND INTENDED READERSHIP
Human beings have steadily been engulfing many species of wildlife,
reducing the space available and damagyig the space remaining through envi-
ronmental pollution. The Impact of this encroachment on wildlife includes
1) loss of habitat and territory; 2) loss of food supply; 3) behavioral
changes involving mating, predation, migration, and other activities; 4)
changes 1n interspecies relationships, such as altered predatory-prey balance
and other aspects of population dynamics, increased competition for food,
shelter, and other limited resources necessary for life. The role that env-
ironmental noise plays in the impact of humans on wildlife is the focus of
this report, although information on domestic and laboratory animals is also
presented. For the purposes of this report, domestic animals include live-
stock, poultry, and other animals raised by humans.
This is the second EPA report on noise and wildlife. The first report
was issued in 1971 (Fletcher, 1971). While 1t was not intended to be an
exhaustive search of the world literature, it did reflect the most important
data then available. Since then the world literature has grown slowly but
significantly. Besides the publication of individual studies, soma of the
most notable informational events have been the following:
e Symposium on the Effects of Noise on Wildlife, at the 9th Interna-
tional Congress on Acoustics (ICA), Madrid, July 1977. Sponsored by
a working group of the Special Committee on Problems of the Environ-
ment (SCOPE) of the ICA, this Symposium led to the publication of a
collection of topical papers the following year (Fletcher and Busnel,
eds., 1978)
e Panel on Effects of fJoise on Animals at the Third International Con-
ference on Noise as a Public Health Problem, Freiburg, West Germany,
September, 1978. The papers presented have been published in the
Conference Proceedings (ASHA, 1980)
• A review written for EPA (Fletcher, unpublished)
e An extensive bibliography on the effects of noise on non-human ver-
tebrates (Bondello and Brattstrom, 1979a)
• A report to be Issued in 1980 by a workshop-on the interaction
between man-made noise and vibration and arctic marine wildlife,
sponsored by the Acoustical Society of America.
*
The Intended readership of this report is diverse, and Includes govern-
ment officials, researchers, and concerned citizens and environmental or con-
servation organizations. Although the Information needs of this readership
are not Identical, it is hoped that the information in this report will be
useful to all groups.
-------
The report has been divided into three main sections: laboratory ani-
mals, domestic animals, and wildlife. Studies within each of the three
sections are further arranged by taxonomic groups and/or individual species,
depending on the amount of material. Reports on each species or taxonomic
group are presented by the four major categories of noise effects: auditory,
masking, nonauditory, and behavioral ef/ects, In some sections, one or more
of these effects categories have been omitted due to lack of 'information.
Throughout this document, sound levels and exposures are reported in the
investigators' terminology. In some cases, the details of reference levels,
weighting schemes, and other acoustic parameters were not given in the origi-
nal sourcer.
OVERVIEW OF EFFECTS OF NOISE
PRIMARY AND SECONDARY EFFECTS
Noise has the potential for affecting organisms in a large number of
ways. The effects of noise on animals may be divided into primary and second-
ary effects. Some hypothetical examples of each are offered for purposes of
clarification (See Table 1). It will be noted that primary effects are the
direct physical effects experienced by the organism, while secondary effects
are reflected in changes in the functioning or performance of the organism
vis a vis its environment.
Thus, the major primary effects of noise on animals may be the same,
whether animals are in the laboratory, on a farm, or in the wilderness.
Secondary effects may be different depending on the life functions of the
particular species.
TABLE 1. Hypothetical Examples of Primary and Secondary Effects
Typa of Animal Primary Effects Secondary Effects
Birds Masking of signals Interference with mating
Small animals Masking of signals Changes in predator-prey
relations, leading to changes
in animal populations
Agricultural, Stress; physio- Changes in meat quality and
Domestic logical responses milk production, weight gain,
egg-laying, egg-hatching
In this report both primary and secondary effects may be addressed,
depending on the data available for a species.
-------
HEARING
The study of the effects of noise on hearing involves both the descrip-
tion of ths normal hearing ability of an animal and hearing loss due to noise.
These two aspects of hearing have been studied frequently in laboratory ani-
mals, but very little in domestic cr wild animals. The effects of noise on
hearing have thus been discussed 1n the next section on laboratory animals.
MASKING
The inability to hear important environmental cues as well as signals
from other animals because of the presence of other sounds is called masking.
Masking of signals of significance to animals may rasult 1n difficulties in
finding mates, in escaping predators, and in communicating with other members
of their species.
NONAUDITORY PHYSIOLOGICAL EFFECTS
The nonauditory effects of noise are not well documented in wild animals.
A nonauditory physiological effect may involve any physiological parameter
other than hearing damage, from hormone levels in ths blood or urine to heart
rate or respiration. Individual researchers have chosen a wide variety of
different physiological rffects of noise to measure 1n animals. Wha^ ties
all of these physiological parameters together is tne body's reaction to
stress. The concept of noise as a stressor 1s basic to understanding the
nonauditory physiological effects of noise on animals. A stressor can be
any agent that causes stress, Including both physical and psychological fac-
tors in an organism. Because of the technical terms involved, more infor-
mation on stress is provided in the Appendix. It includes information on
stress in general and on noise as a stressor in particular.
BEHAVIORAL EFFECTS
Noise can be very frightening and disturbing to both humans and lower
animals. Animals vary tremendously 1n their overt responses to noise, rang-
ing from near indifference to flight. The behavioral reaction of an animal
to noise depends on the source of the noise, whether or not tha noise is
expected, the acoustic characteristics of the noise (loudness, duration, fre-
quency pattern), the experience of the individual animal, and whether or not
other stressors c-.re present (e.g., frightening objects, humans, chemical or
physical agents).
There are many reports of..animal responses to noise from sonic booms,
aircraft flyovers, power transmission lines, and many other noise sources.
Enough data have been collected to be able to predict the behavior of certain
types of animals, including domestic species and wilderness species such as
wild sheep, caribou, and moose*
-------
ETTRODUCTION
This laboratory research section is included in this report because
the findings display the range of potential effects which may occur in other
envii-onoents under comparable conditions. It should be noted, however, that
mo it of the laboratory research is conducted for the purpose of understanding
lu.ie tbout factors affecting humans, rather than to understand these effects
c... animals in natural environments.
Laboratory animals generally Include inbred species raised in special
colonies for use in research. Common laboratory aniraals raised in this in-in-
ner include many rodents or lagomorchs, such as rats, mice, hamsters, rabbits,
guinea pigs, and chinchillas, as well as mcnkeys and other primates. There
are also species coranonly used as laboratoo animals, which may or may not
have been raised under controlled breeding conditions. These species include
a number of animals more frequently used as pets, such as cats «md dogs. The
wild counterparts to any of these laboratory animals will be treated in the
section on oildlife.
Although many laboratory animals have wild counterparts (rats, mice),
the wild species are clearly different in many ways - genetically, behavior-
ally, and physiologically. Thus, a treajor problem with laboratory animal
research is the ability to make generalizations about results from one
species to another and from laboratory to natural conditions. Despita this
constraint, laboratory wcrk offers the advantages of being able to control
the experimental conditions, including: (1) the characteristics of the
sounds to which the animals are exposed, such as frequency spactnjra, dura-
tion, pattern of exposure and exposure level; (2) the factors determining
species' susceptibility or individual susceptibility to noise induced damage,
such as hearing sensitivity and auditory range, age, sex, presence of other
stressors, and genetic background.
There are several factors to consider in evaluating the studies pre-
sented in this section. The first is that the ricise lavels used in many
of the studies are very high (over 100 decibels)* Since these levels are
much beyond what we would normally find anisals exposed to around airfields,
industries, highways, or most other intrusions b> man into their habitat,
direct generalizations to non-laboratory conditions are inappropriate.
Another factor to consider is that the duration of noise exposure is often
very short so that trost of the studies explore acute rather than chronic
effects. A further consideration about these studies is that auditory sen-
sitivities to intensity; and frequency vary widely froa one species to
another. This could be a significant factor, especially with regard to
oeasurement and frequency weighting of noise exposures. In spite of these
factors, the studies show that noise can affect many bodily functions and
they point cut areas -ftsr special study in wild and domestic animals.
Due to the very large number of reports available on the effects of
noise on laboratory animals, we have selected only a snail number of repre-
sentative original studies and review articles for inclusion in this report.
-------
HEARING
The study of the effects of noise on hearing includes measuring normal
hearing levels for the species being studied and investigating noise-induced
hearing loss. The studies* in this section will be confined to hearing loss
from physiological damage to the auditory system. Another auditory phenome-
non, masking, is the result of interference with signal detection by a com-
peting noise, and will be treated separately,
Laboratory animal species differ in both hearing sensitivity and suscepti-
bility to noise-induced hearing loss. Many common laboratory animals, such as
chinchillas, cats, guinea pigs, and monkeys, may be more susceptible to ncise
damage than humans (Peterson, 1980). Rodents, which are the most common labo-
ratory animals, are acutely sensitive to very high frequency sound—up to
60,000 to 80,000 Hertz (Hz, or cycles per second) (Peterson," 1980) and even
100,000 Hz (Lee and Griffith, 1978). Anyone who has had a pet dog or cat
Knows from observation that these animals are sensitive to higher frequencies
than humans can hear (as a dog whistle illustrates). For further information
en hearing sensitivities of different animal species, see Susnel (1963).
As in humans, the best documented effect of noise on laboratory animals
is the production of hearing loss or damage to the auditory system. This can
be produced by a brief exposure to very loud sound or by prolonged exposure
to moderate levels of sound. To study hearing loss, it is nacessary to mea-
sure hearing abilities before and after exposure to noise. Either electro-
physiological recordings from the auditory system or behavioral responses of
the animal can be used to assess the sensitivity of the ear. The Preyer
reflex, and ear-twitch response to sound, indicates that an animal has heard
a sound. This reflex is a reliable, but not very sensitive, test of hearing
in animals, because they are capable of hearing sounds that are less intense
than the sound that produces the response. Alternatively, an animal can be
trained to respond to a sound stimulus by using the sound as a cue to obtain
reward (such as food) or to escape from punishment (such as electric shock).
If the animal is appropriately motivated (i.e., hungry or fearful of shock,
depending on the circumstances), its responses can serve as a sensitive indi-
cator of which sounds it hears. An animal's hearing can be tested, the animal
then can be exposed to noise, and hearing can be retested to determine tha
decrease in hearing ability, or threshold shift (Fletcher, 1971).
Brief, moderate noise exposure can result in a temporary threshold shift
(TTS), in which there is a temporary elevation of the level of faintest audible
sound. Given a sufficient quiet recovery period, hearing will return to nor-
mal. More severe noise exposure can result in permanent hearing loss, or per-
manent threshold shift (PTS). Animal studies tend to confirm findings in
humans that TTS grows to an asymptotic level (asymptotic threshold shift or
ATS) for a sound exposure of a givsn level and a relatively long duration
(Moody, et al., 1978; Mills, 1976). The relationship between TTS and PTS is
still unknown.
A recent study by Libermanl'and Bell (1979) compared histological data
from the hair cells in cochleas from cats raised under normal or noisy labo-
ratory conditions for up to two years. Noise-induced threshold shifts were
correlated with loss or damage £o the hair cells. Similar studies using mon-
keys (genus Macaca) and a baboon (Papio papio) correlated cochlear pathology
and hearing loss due to chronic exposure to octave band noise of 117 to 120
decibels sound pressure level (Moody, et al., 1976; Moody, et al., 1978).
-------
Besides the attributes of sound level or Intensity, It Is useful to
describe sound 1n terras of Its frequency spectrum. It has been mentioned
that animals of different species have different frequency sensitivities.
The frequency content of sound is also Important because sounds of different
spectra affect the auditory systeia differently, regardless of species. High
frequency pure tones or narrow bands of noise tend to produce changes in
localized regions of the inner ear. whereas low frequency tones, and random
or broad-band noise tend to produce changes throughout the length of the
cochlea (Fletcher, 1971). The recent data of Moody, et al. (1978) show that
1n monkeys (Hacaca) hearing losses due to noise were "usually asymmetrical
towards the higher frequencies," suggesting'that, for these animals, there
may be an area roughly between 2000 and 8000 Hz which 1s more susceptible to
damage from noise.
Noise datnaga in the laboratory is frequently produced by impulse noise.
Impulse noise is sound that rises very rapidly to its maximum Intensity, such
as the firing of a rifle. Because of the very short durations uf Impulse
sounds, they are described in terms of rise time, maximum intensity (peak
pressure level), and duration. The rise time of an fmpulse sound is often
around a few thousandths of a second. If an impulse sound 1s sufficiently
intense, the rapid pressure changes produced can cause permanent loss of
hearing, usually by destroying sensory cells in the inner ear.
Auditory oamage frota simulated sonic booms has been found in mice by
Reinis (1976). Bleeding in the scala tympani at the basal turn of the cochlea
was found after a "super boom" of 10 pounds per square foot overpressure with
a 5 mi 111 second rise time. (Tin's is a rauch greater sonic boom than humans
typically experience in the environiBent.) The same damage was produced by a
less intense sonic boom of 3.3 pounds per square foot overpressure (about 1£0
decibels instantaneous peak) with a 0.1 millisecond rise tics and a duration
of 120 milliseconds. When the mice were subjected to repeated sonic boons,
an increase in the number of blood clots in the inner ear was observed, even
irora noise exposure of one boom per day. Bleeding was no longer present
after 8 weeks in quiet.
A study by Henderson, et al. (1979) subjected 6 monaural chinchillas to
simulated work-week exposure to repetitive, reverberant impulse noise for 5
days, 8 hours per day. The impulse noise consisted of automated brass ham-
mers hitting a steel plate at a rate of one per second. The average peak
overpressure was 113 decibels with a reverberation time of 160 nsilliseconds.
Auditory thresholds were measured before and after eacn exposure, daily for
5 days after the last exposiire, and again at 30 days. Thresholds were mea-
sured at 250 to 8000 Hz. The noise exposure was found to produce an asymp-
totic threshold shift. In this study, the higher frequencies (4000 to 8000
Hz) were affected to a greater degree (40 decibel shift) but recovered mo-e
rapidly than the lower frequencies '500 to 1000 Hz), which showed a 35 deci-
bel shift. No cumulative effect was observed from day to day, and very
little permanent threshold shift w*s found at the end of the experiment.
Although noise-induced hearing damage ha? been studied & great deal in
laboratory animals, "the complex relations between noise spectrum, noise
intensity, exposure duration, and hearing loss are not yet completely under-
stood" (Saunders and Bock, 1978, p. 259). In addition, although many studies
have been done on the anatony, physiology, and biochemistry of noise damage
to the inner ear, the actual mechanisms for .the noise damage have not been
conclusively shown. A detailed discussion of these proposed mechanisms is
given by Bonne (1976).
-------
In summary, auditory.damage 1n laboratory aninuTi has been studied inten-
sively for many years. Laboratory animals often serve as models for noise-
induced hearing loss mechanises in humans. There is additional interest in
the safety of the laboratory animals themselves, since their condition affects
the results of any experiments for which they are used. It is important to
note that there are no quantitative exposure limits for animal housing facil-
ities, sine? damage risk rriteria have almost exclusively been investigated
for human health. Research is also limited.on the existing noise levels of
the animal housing areas. The extrapolation of exposure criteria from humans
to laboratory animals is extremely questionable (Peterson, 1980).
•
NONAljBZTORY PHYSIOLOGICAL EFFECTS
Noise may be thought of as a stressor, producing physiological changes
similar to those induced by extreme heat, cold, pain, or emotional distress.
A major problem is studying the nonauditory effects of noise is to separate
the effects of noise from those of other stressors in the environment. This
problem exists even ;fn a laboratory setting, where other stressors may include
crowding, fear,, excess light, toxic substances (pesticides, disinfectant), and
various, diseases (Peterson, 1980).
The general pattern of response to stress includes neural and endocrine
activation, stimulating many changes, such as increases in blood pressure,
available glucose, corticosteriod levels in the blood, changes in the adrenal
glands and changes in digestive and respiratory activity. These responses
are inediated by the sympathetic nervous system (Holler, 1978), which is the
part of the nervous system that responds to stress. The sympathetic nervous
system and the parasympathetic nervous system work antagonistically to make
up the autononric (or vegetative) nervous system. The autonomic nervous sys-
tem maintains homeostasis in the body by regulating the composition of body
fluids. The autonomic nerves affect circulatory, respiratory, excretory and
endocrine functions (Cantrell, 1979), by stiitiulation of smooth muscle, car-
diac muscle, and various glands (such as the adrenals).
A sudden or unfamiliar sound is thought to act as an alarm or warning
signal, this activating the sympathetic nervous system. The short-term physi-
ological alarm or stress reactions are similar across many vertebrate species
(Holler, 1978). They are often referred to as "fight-or-flight" reactions
because they prepare the body to defend itself. The effects of repeated acti-
vations of this mechanism in a noisy environment are not understood, but some
of the studies discussed in this section address this question.
Some studies show that animals may become accustomed to continuous noise,
such that certain physiological reactions to the noise no longer occur (habi-
tuation). Habituation to intermittent noise, however, occurs more slowly.
For example, this was demonstrated with respect to peripheral vasoconstriction
in rats by Borg (1979). There, is some evidence that other responses, such as
changes in blood pressure, do not seem to habituate, but rather increase in
magnitude with long-term exposure to complex noise stimuli (Peterson, 1979;
Peterson, et al; 1980).
It is interesting that atj.the other extreme, the absence of noise can
produce a form of sensory deprivation stress, resulting in hypertension and
various endocrine changes in rats (tfetz, 1978).
-------
An animal's body can respond physiologically to sound stimulation even
while the animal is aslaep, under anesthesia, or after removal of its cere-
bral hemispheres (Welch, 1970).
The studies included in this section are presented below according to
the various types of physiological effects being explored. Further detailed
information on the mechanises of these responses is presented in the Appendix.
"Noise as a Stressor."
CARDIOVASCULAR EFFECT!
The effects of noise on the cardiovascular system, which includes the
heart and blood vessels, are among the most frequently demonstrated nonaudi-
tory effects. Specific cardiovascular responses that occur include pheriph-
eral vasconstriction, heart rate deceleration, heart rate acceleration,
increased blood pressure, elevated serum lipids (free fatly acids, triglycer-
ides, and cholesterol) ana increased platelet adhesiveness and aggregation.
The animal species most commonly usea for studying the cardiovascular effects
of noise are rats, rabbits, and more recently, monkeys. A major reason for
studying the cardiovascular effects of noise is to see whether chronic noise
exposure is a factor 1n the development of hypertension, atherosclerosis, or
other cardiovascular diseases. Although there is evidence that noise is
implicated, the results of many studies are conflicting. A ccnqjrehensive
review of noise, stress, cardiovascular disease, and their interrelationships
has recently been completed by Hattis and Richardson (1980). Some of the
most significant findings will be discussed here.
Noise stress has been shown to increase plasma renin activity. Since
plasma renin activity may be related to hypertension, the effects of noise
stress on this measure were studied in rats by Vander, et al. (1977). Tha
noise exposure consisted of broadband noise or a 2000 Hz sound presented at
various levels between 80 and 115 decibels sound pressure level for 30 min-
utes. Control animals on both diets received no acoustic stimulation. Sroups
of rats given a normal diet were compared to rats given a sodium-free diet,
since increased renin activity stimulates sodium retention. No increase in
renin activity was produced by the 2000 Hz sound in any of the animals, at any
of the levels. Broadband noise significantly increased plasma renin activity
in rats on the normal diet but only at the 115 decibel level. The rats on a
sodium-free diet showed a significant increase in renin activity when exposed
to the 100 decibel broadband noise. Since sodium deprivation increased the
effect on renin activity and reduced the noise exposure threshold for the
effect, it follows that sodium deprivation may increase the renir.-releasing
effects of noise exposure and perhaps other stressors.
The development of atherosclerosis due to chronic noise exposure was
studied in several groups of female rabbits by Oeryagina, et al. (1976). The
test rabbits were given either noise alone or noise plus daily oral doses of
cholesterol (500 milligrams cholesterol in 5 railliliters of sunflower oil).
The noise exposure was 94 to 96 decibels at 3000 Hz for 4.5 hours daily,
Including two 30-minute quiet periods every 1.5 hours. The total length of
exposure was 14 or 28 days. The animals receiving cholesterol were given
daily doses for 4.5 to 5 months^. Those receiving both noise and cholesterol
were given the noise exposure in the first 14 or 28 days. Control groups
were given either no cholesterol and no noise or cholestero? alone. Major
changes due to 'ioise exposure alone for 14 days included higher blood levels
-------
of nonesterifled fatty acids and increased blood hypercoagulation. Noise
alone induced some microscopic atherosclerotic changes, and noise also
enhanced gross atherosclerotic changes in the coronary arteries (such as
increased platelet adhesiveness) caused by the high cholesterol diets.
The effect of long terra noise exposuras on blood pressure and heart
rate has been under investigation for the past severs! years in Rhesus
raonkeys. Preliminary experiments (Peterson, et al.» 1975) showed that both
continuous noise (recorded urban noise-at an equivalent noise level, Leq,
of 78 A-weighted decibels) and intermittent noise (signaled "noise bursts at
112 decibels for 9 seconds) produced sustained cardiovascular changes. The
continuous noise recording was played 12 hours daily for 30 days, after the
monkey had been monitored for a 30 day baseline control period. Hourly
blood pressure and heart rate reasurements were performd. Major increases
in t'nesa functions occurred in the early morning and declined during th(
rest of each day. intermittent noise presented up to 8 times daily for 30
days produced increased heart rate and blood pressure. The most important
finding was an overall average baseline blood pressure increase of 28 percent.
This preliminary work was followed up by exposure of Rhesus monkeys to
nine months of a daily round-the-clodc tape recording designed to simulate
the noise exposure of an industrial worker (Peterson, 1979; Peterson, et al.,
1980). The tape included an eight-hour period (with a short "lunch break" at
noon) of impulsive and continuous industrial noise, transportation noise
before and after the "workday" period, household noise in the morning and
evening, and low-level sounds such as aircraft overflight noise during the
night. The overall equivalent level (Leq(24)) was 85 decibels. Monkeys
were adolescent females with initial blood pressure levels at about the 50th
percentile for Rhesus monkeys. They wore chronically implanted catheters to
accurately measure blood pressure levels.
After nine months, the monkeys displayed elevated systolic blood pres-
sure, 137 ran Hg, compared to a pre-exposure average of 106 mm Hg, to an
increase of 29 percent. A similar increment was found in diastolic blood
pressure.
The noise exposure was then terminated for one month. At the end of
this month, blood preiSures showed no indication of returning to normal.
Long-term noise exposure has also been studied in the rat (Borg and
Holler, 1978), producing very different results from the previous monkey
experiments. Both normotensive Sprague-Dawley and spontaneously hyperten-
sive Wistar (Okamoto strain) rats were tested. Groups of rats were exposed
10 hours daily to 85 or 105 decibels sound pressure level over their life-
time of about one year. Th» noise stimulus was considered meaningless to
the rat and consisted of intermittent noise from four Lancing L 75 horns
(presented during the night, the time when rats are most active). Control
rats were exposed to background noise, produced by the rats themselves, of
about 50 A-weighted aecibels. No significant long-term differences in sys-
Lolic blood pressure were found between noise-exposed and unexposed rats
in either males or females, or between normotensive and spontaneously hyper-
tensive rats. Thes* results tend to contradict previous findings in rats
(Buckley and Smookler, 1970; Geber, 1970).
10
-------
NEUROENDOCRINE EFFECTS
For a detailed explanation of some neuroendocrine relationships, see the
Appendix. Noise stress may produce many of its effects via corticohypothala-
mic interactions with the hypophyseal adrenal system. Werner (1959) studied
the effect of sound on the hypophysis {the pituitary eland) of the rat. He
found that long, continuous bell ringing (8 hours per'day) from 1 day to 3
weeks resulted in hypertrophy in the pars intermedia of the pituitary and
hyperactlvity in the adrenal cortex (increased cortisol secretion).
Ogle and Lockett (1965) studied the effect in rats of recorded thunder-
claps of 3 to 4-seccnd duration with a frequency range cf 50 to 200 Hz at 98
to 100 decibel sound pressure level, presented at a rate of two claps at
1-minute intervals every 5 minutes for 20 minutes. They compared this effect
with that from a pure tone of 150 Hz at 100 decibels presented for 2 minutes
out of every 15 minutes for 45 minutes. Urine was collected and analyzed for
sodium and potassium.. Responses to noise vere' analyzed through comparisons
among animals that were intact, that had denervated kidneys, and that had
neurohypophyseal lesions. The authors concluded that thunderclaps produced
emotional responses which the 150-Hz tone did not produce. Thunderclaps
affected the hypothalamus resulting in excretion of oxytocin (stimulates the
uterus) and vasopressin (anticiiuretic hormone, which raises blood pressure).
These hormones produced increases in sodium and potassium excretion with no
increase in urine flow (Fletcher, 1971).
Because the adrenal hormone cortisol is always released during stress,
many investigators have measured the effects of noise on adrenal size, cor-
tisol levels in the blood, or the effects of the absence of the adrenals.
Yeakel et al. (1948) exposed adrenalectomized Norway rats to the sound of a
blast of compressed air 5 minutes a day, 5 days a week- for a year. The aver-
age systolic pressure in the noise exposed rats rose froni an initial value of
113 run Hg to 154 mm Hg in the last 2 months, while control values rose frop
124 to 127 mm Hg. The absance of the adrenals leaves an animal with no abil-
ity to cope with stress by means of increased cortisol secretion.
More recently, Osintseva, et al. (19S9) exposed rats to an 80 decibel
noise for various times from 18 to 126 days. Following exposure to nuise,
analyses revealed significant drops in the ascorbic acid contents and weights
of the adrenals of these rats relative to the controls.
In another study the same year (Hiroshige, et al. 1969), rats were
exposed to continuous bell-ringing for 2 minutes (spectrum and noise level
were not reported). Bell-ringing produced an increase in the activity of
corticotropin-releasing factor (CRF) in the hypothalamus. This releasing
factor (also called ACTHRF) produces the release of adrenocorticotrophic
hormone (ACTH) from the pituitary; ACTH, in turn, produces the release of
corticosteroids (cortisol, corticosterone, aldosterone) from the adrenals.
Adrenocortical activation has also been studied quite extensively in
rodents by Anthony and Ackerman (1955, 1957) and by Anthony, et al. (1959).
They exposed rats, mice, and giiinea pigs to relatively broad bands of intense
noise: 150 to 430 Hz at 140 decibels sound pressure level, 10,COO to 20,000
Hz at 110 decibels, or 2,000 to 40,000 Hz at 132 decibels. Durations of
stimulation periods included a-single 6 minute exposure, 15 or 45 minutes per
day for up to 12 weeks, and cycles of 100 minutes on and 100 minutes off
throughout a 4-week exposure period. Although they obtained indications of
adrenal activation (as measured by cellular changes in the adrenal glands
and a decrease in the number of circulating eosinophils), these changes
11
-------
were generally slight and transient. They did find, however, that Intense
noise superimposed on another stressor, such us restriction of food, could
decrease an animal's life span. Ths authors concluded that rats, mice, and
guinea pigs can become accustomed to noise, but that noise can have damaging
effects if It occurs 1n conjunction with additional stressful situations.
They also noted that intense high frequency neise (132 decibels, 2000 to
40,000 Hz) appears to be more stressful thaa^lew frequency noise as evidenced
by an Increase in noise-Induced seizures in mouse strains considered to be
seizure-resistant (Anthony and Acker-man, 1957).-
In the 1970's, noise researchers began using monkeys in studies on cor-
tlsol levels. Nealis and Bowman (unpublished) studied the effects of three
types of noise on plasma cortlsol levels in 12 Rhesus monkeys. The results
were compared to those of a control group of four monkeys. The three types of
noise' consisted of continuous noise (recorded power tools and land vehicles),
noise of variable level (rock music), and impulse noise (shotgun blasts, pis-
tol shots, and machine gun blasts, randomly presented). Over a period of 36
days, each of the four test animals was subjected to the three types of noise
1n exposure sessions of one, three and five hours. A minimum of 90 hours
separated the treatments. The average A-weighted noise exposure level was
100 decibels. Test monkeys were divided into 3 groups of two males and two
females each. The order of the treatments was randomly assigned for each
group. The plasma cortisol levels were not affected differently by tins three
types of noise stimuli. Elevated plasma cortisol levels were found after one
hour of exposure to all three types of noise, but not after the three or five
hour exposures. After an initial stress or fear reaction, the monkeys appar-
ently habituated physiologically to tne noise.
A similar experiment was performed by Hanson, et al. (1976), except that
some of the test animals were able to terminate the noise by depressing .
lever (control over noise group). The noise exposure consisted of four 13-
minute noise sessions with two minutes of quiet between them. The noise con-
sisted of a continuous recording of power tools, pneumatic drills, snowmobiles,
and machinery at 100 decibels. In the first part of the experiment, the 24
monkeys (one- and three-year olds) of both sexes were divided into a control
group (no noise), a test group with no control over noire, and a test group
with control over noise. The latter group experienced its first 13-nrinute
session with noise before being able to turn it off. In the second part of
the experiment, the animals which had had control over the noise in the first
part were intermittently presented with the termination lever, but pressing
the lever did not terminate the noise. Pre-exposure plasma cortisol levels
were equivalent for all three groups. Plasma cortisol levels were signifi-
cantly elevated both in the group that had no control over noise and in the
animals that lost control over noise in the second part. The cortisol levels
of monkeys with control over noise were not significantly different from those
that had no noise exposure.
Because Increased adrenocortical hormones due to stress have been related
to decreased thyroid functions, Fell, et al. (1976) studied the effects of
acoustic stress on the thyroid glands of rats. The test animals were sub-
jected to a single 1000 Hz tons, (at 95 decibels) for 15 minutes, twice per hour
for 8 hours dally during the daytime for 12 weeks. The test animals were free
of gross hearing abnormalities; bastd on random inspections during the expo-
sure period. Thyroid activity^ measured by .uptake of radioactive iodine
(1-131), was suppressed in the rats exposed to noise. The suppression began
12
-------
1n the first two weeks for females and between two and 12 weeks 1n the males.
Similar sex differences were observed regarding the weight gains of the ani-
mals. The females had significantly reduced weight gains during the first 2
weeks of noise stress, whereas the males did not show reductions in weight
gain until the sixth week.. A possible explanation for this finding is that
altered thyroid function due to stress may decrease the secretion of growth
hormone from the anterior pituitary (adenohypophysis).
Another nervous system parameter, activity of acetylcholine (a neural
transmitter), was studied in the rat brain by Brzezinska (1968). Exposure to
noise (type and level not reported) for 2 hours a day for 3, 6, 9, 12, or 15
days produced a gradual increase in acetylch'olinesterase activity (which causes
the breakdown of acetylcholine) and an initial increase in acetylcholine con-
centration followed by a decrease, with a slow return to normal levels by 15
exposures. Since stress induces Increased sympathetic nervous system activity,
such increases in acetylcholine levels would be expected.
BIOCHEMICAL PARAMETERS
A number of other effects of noise, particularly on blood chemistry, are
included here. Most of the blood levels of various chemicals are related to
cardiovascular, neuroendocrine, or a variety of other metabolic functions.
Treptow (1966) found that dogs had transitory increases in glyceraic
(sugar) levels in the blood pn'or to becoming used to the stress of experi-
menter handling. A predictable incredse in glyceraic reactions was observed
in trials one and eight out of 20 exposures to 80 to 87 decibels noise for 5
to 10 minutes each. Due to individual reactions, the measures were highly
variable, but by trial 20 the glycenric response had apparently habituated to
the noise stimulus.
Stress induces a number of other biochemical changes. Jurtshuk, et al.
(1959) subjected two group of female rats to 1 minute of noise daily for 11
days or to 5 minutes of noise for 15 days respectively. The noise consisted
of 120 Hz at 100 (+ 5) decibels. Rats that displayed the greatest locomotor
response upon cessation of auditory stimulation also had the lowest blood
glutathione (a respiratory carrier of oxygen). Stimulated rats had higher
adrenal weights and ascorbic acid values and lower blood glutathione levels
than did their controls.
Geber, et al. (1966) investigated the physiologic response of rats to
three durations of acoustic stress (15 to 270 minutes, 19 to 96 ncurs, and 21
days). The stimulus was a 20,000 to 25,000 Hz sound, ranging from 73 to 93
decibel sound pressure level, presented 6 minutes of every hour. They noted
lower eosinophil counts, raised serum cholesterol levels and Increased ascorbic
acid levels in the brain. Elbowlcz-Warfewska (1962) observed that when guinea
pigs were exposed for one month to daily 45 minute periods of noise at 160 { + 5)
decibels sound pressure level with frequencies frora 100 to 50,000 Hz, Increases
in lactic acid dehydrogenase (LOH) activity and pyruvic acid levels in the blood
were observed. Diseased c^lls tend to discharge greater amounts of certain
enzymes into the blood. Elevated LDH is symptomatic of cardiac, liver, kidney,
muscle, and brain disorders (Holvey, 1972).
Hrubes (1964) found that nonesterified fatty acids, the plasma Hpids
most implicated in active transport within cplls, increased significantly in
female white rats when the rats wera exposed to a 95 decibel transmitter
generator noise for 16 hours. Hrubes and Benes (1965) demonstrated that
13
-------
white rats subjected repeatedly to 95 decibel noise secreted increased levels
of urinary catecholamines, showed increased free fatty acids in blood plasma,
Increased adrenal size, and decreases in body weight.
Similar findings were reported by Friedman, et al. (1967), who demon-
strated that auditory stimulation can affect lipid metabolism. White noise
at a sound pressure level of 102 decibels was presented 24 hjurs a day, and
an additional intermittent 200 Hz square wave with a duration of 1 second
and a sound pressure level of 114 decibels was programmed to occur randomly
with an average interval of 3 minutes. Thirty rats were expcfsed to the noise
stimuli for 3 weeks, and 24 rabbits were exposed for 10 weeks. These animals
received standard diets and water, but were administered additional oils to
test their abilities to handle excess fat while exposed to noise stress.
Plasma triglycerides were higher in noise-exposed rats only during the second
week; there were no differences between experimental and control groups of
rats at the end of weeks 1 and 3. In the rabbits, however, plasma cholesterol
and fasting plasma triglycerides were higher after four weeks of auditory
stimulation. Additional differences between the noise-stressod rabbits and
the controls included deposits of fat in the irises of the eyes, more aortic
atherosclerosis, and a higher cholesterol content in the aortas. The authors
concluded that auditory stress produces changes in the metabolism of exogen-
ously delivered fat, having effects similar to those produced by chronic
hypothalamic stimulation (obesity).
PULMONARY EFFECTS
Ponomar'kov, et al. (1969) reported noise-inciucdd pulmonary hemorrhages
in dogs. The animals were exposed to 0.6 to 3.5 second bursts of white noise
at 105 to 155 deci!els. Two hours after exposure, 3-millimeter diameter
hemorrhages were found in the lungs of those animals exposed to noise levels
exceeding 125 decibels. Increased noise levels resulted in increased numbers
of hemorrhages, but not in increases in the size of each site. Emphysematous
changes induced by noise exposure were still detectable at 60 days pcstexpo-
sure, even though hemorrhaged blood had been resorbed.
RESISTANCE TO DISEASE
As explained in the Appendix on stress, extreme elevation of cortisol
levels can reduce both the inflammatory response and antibody production
(Vander, et al., 1975). It has also been suggested that mild chronic eleva-
tion of cortisol levels could also lead to reduced immunity, although defini-
tive evidence of this has yet been found.
At least one experiment has shown there is a relation between noise expo-
sure and susceptibility to viral infection in strains of mice susceptible to
audiogenic seizure (see next section). Jensen and Rasmussen (1970) used an
800 Hz tone with an intensity of 120-123 decibels for 3 hours each day on 6-
to 8-week old Swiss Webster 3RVS mice. Mice innoculated intranasally with
vesicular stomatitis virus (cau|es eruptions in the mouth) just before expo-
sure to sound were more susceptible to the infection, while mice innoculated
after the exposure were more resistant. The sound-stressed mice were also
more susceptible to polyoma virus (which produces tumors) and developed more
tumors than controls that were not sound-stressed. The progression of Rauscher
14
-------
virus leukemia was suppressed in noise-exposed animals. The inflammatory and
interferon (a virus-resistant protein produced by -ells) responses were also
impaired by sound. Sound-,stressed mice also had periods of variable suscep-
tibility to viral challenge within each day. At sorce of these periods, the
sound-stressed mice had similar susceptibilities to the non-stressed controls.
This transitory change in susceptibility was found to be independent of adre-
nal function, indicating that other factors may also be involved in disease
resistance.
AUDIOGENIC SEIZURE SUSCEPTIBILITY
Certain strains of rodents are extremely sensitive to intense sound.
These rodents undergo such violent audiogenic seizures, that exposure to
noise can result in death. Young rodents may become audiogenic stizure-
susceptible if exposed to loud noi^e during a critical period after birth
(priming). Priming is used in laboratory rodents to produce experimental
animals for the study of epileptic seizures, as rrodels for severe acoustic
trauma, and in the study of auditory development in young animals (Saunders
and Bock, 1978).
Monastyrskaya et al. (1969) reported that sound stimulation produced
increases in weights of the pituitary and adrenal glands in healthy rats, but
not in a strain of sound-sensitive, audiogenic-seizure susceptible rats. The
sound-sensitive rats already had enlarged pituitaries and adrenals. The rats
were exposed to a 105 decibel sound 10 times, for 1.5 minutes each time, with
one exposure every 3 to 4 days.
Reproductive effects of noise have also been studied in audiogenic
seizure susceptible animals. There is evidence that sound stimulation may
induce lasting changes in exposed animals and their offspring in strains of
mice that have been specially bred to be susceptible to audiogenic seizures.
Lir.dzey (1951) studied emotionality and audiogenic seizure susceptibility in
mice exposed to noise. The animals were stimulated by the sound from a bell
attached to a metal washtub (spectrum and sound pressure level were not
specified). He reported increased susceptibility to seizure in certain
strains of mice. Thompson and Sontag (1956) described effects of audiogenic
seizures in pregnant rats on the maze-learning abilities of their offspring.
Each of six male albino rats was bred to one experimental and one control
female. Two seizures per day were induced from the fifth through the 18th
day of pregnancy in each of the six experimental females. Within 24 hours of
birth two male and two female pups were selected from each litter and the
rest were removed. Three mothers in the experimental group and three in
the control group kept their own pups, while the pups of the other three
mothers in each group were switched between groups so that pups from experi-
mental (seizure) mothers were cross-fostered on control mothers and vice
versa. At 21 days of age,, the pups were removed from the others and housed
in individual cages in the animal room. General activity levels were tested
at 30 and at 60 days of age. training in a water maze began at 80 days of
age. Although there were no significant differences in body weights, litter
sizes, or activity levels, there were significant differences between experi-
mental and control groups in mlze learning.1 Pups born to mothers that had
audiogenic seizures during pregnancy made significantly more errors and
required significantly more trials than did pups born to controls, even if
the control pups were cross-fostered on experimental mothers.
15
-------
REPRODUCTIVE EFFECTS
Studies on the reproductive effects of noise have examined the impact on
both adults and offspring. In adult animals, this research has addressed
genital function, fertility and mating. Studies of the offspring of anisals
exposed to noise during pregnancy have investigated the following parameters:
fetotoxicity, teratology, gestation, litter size, birth weight, and aspects
of development.
A fa* studies of noise effects off male reproduction have been done.
Anthony and Harclerode (1959) reported negative results in a study of the
effects of noise on the numbers of females impregnated by sexually mature
male guinea pigs. Twelve weeks of daily exposure to noise (139 to 144 deci-
bels sound pressure level; frequencies of 300 to 4,800 Hz) for 20 minutes out
of each 30 minute period did not affect the reproductive performance of the
animals relative to their controls. Some evidence of corticoadrenal activa-
tion was found, however, suggesting th?*-. tolerance limits were approached.
Effects of testicular histology were observed by Zoric (1959). He exposed 38
male mice for 8 hours per day for 1 to 21 days to the sound of an electric
bell. The level and spectrum of the sound were not reported. Studies of the
testes of sound-exposed mice revealed involution (shrinkage) of the seminal
epitheliura, partial blockage of first order spermatocytes, formation of tera-
tocytes, and atrophy of the epithelium.
Reproductive s.udies comparing the effects of noise on males and females
have also been undertaken. Zondek and Isachar (1954) examined the effect of
acoustic stimulation on genital function in 48 mature rabbits and 3,100 young
and mature rats. The animals were housed near an electric bell 25 centimeters
in diameter that rang 1 minute out of every 10 minutes, 24 hours per day, for
9 days prior to mating. The peak sound pressure level was 100 decibels, with
maximum energy at 4B000 Hz, and another peak of 95 oecibels at 10,000 Hz.
Auditory stress resulted in enlargement of the ovaries, persistent estrus,
follicular hematomas, and other effects in female rats and rabbits. Effects
were more pronounced in female rabbits than in female rats and were hardly
visible in males of either species. Auditory stress during the copulatory
period induced increased fertility, but during gestation such stress inter-
rupted pregnancy (Fletcher, 1971).
Another fertility study contained some contradictory findings. Zcndek
(1964) reported that in rats, the fertility of both males and females was
decreased with noise exposure. The males' ability to fertilize was reduced
to 11 percent as compared to 70-80 percent 1n control males; coasparable
effects were produced 1n the female rats. Sexual behavior did not seeia to be
inhibited (copulation was verified by the presence of a vaginal plug), and
there were no changes in the weights of the testes and sejrinal vesicles, nor
any noticeable anatomical changes in the spermatogenic process. In sirailar
fashion, Singh and Rao (1970) studied the effects of auditory stress on rat
ovaries. They exposed 74 adult female rats to continuous auditory stimula-
tion by a 2,000 Hz tone at lOfr-decibels (C-weighted) for up to 150 days.
Thirty-one animals developed p'ersistent vaginal estrus after 10 consecutive
days of stress. As the stress was continued, more animals were affected.
Noise may also affect the offspring of laboratory animals. Ishii and
Yokobori (1960) found that fenfele mice exposed to 90, 100, or 110 phons of
white noise for six hours per day from th» llth through the 14th day of
pregnancy had more stillborn and more malformed young, and smaller embryos
than the unexposed controls.
16
-------
Teratogenic effects .produced by audiogenic stress were also reported by
Ward, et al. (1970). A motorcycle horn producing 82 to 85 decibels sound
pressure level at 320 to 580 Hz was timed to deliver noise intermittently for
60 tj 75 percent of each hour. Female albino mice (Swiss-Websr.er strain)
were placed 1n the chamber and exposed to the noise for periods of at least
five hours at different stages of pregnancy. The most severe effects were
obtained with stress 8 hours per day on days 8 to 17 of pregnancy. In these
cases, 40 percent of the litters were^resorbed and mean fetal weight was 0.44
grams, while mean fetal weight in control litters was 1.45 grams. Although
only moderate noise levels were used, there were severe results if stimula-
tion occurred during critical periods. Stress during days 7 to 8 resulted
in 100 percent resorption by day 18. Observed teratogenic effects (cranial
hematoma, dwarfed hind limbs, and tail defects) were attributed to endocrine-
logic effects of stress on the mother and/or the fetus. These stress effects
resulted in discharge of ;atecho!amines and steroids from the adrenals.
Decreased uterine and placental blood flow were considered to be responsible
for fetal hypoxia and possibly delayed implantation.
Teratogenic and other reproductive effects were studied by Kirnmel, et al.
(1976) 1n offspring of pregnant mice and rats subjected to 100 decibel white
noise (20 to 20,000 Hz). The mice were exposed to ncise during days 3 to 6,
7 to 10, or 11 to 14 of gestation. The rats were exposed on days 6 to 15.
The incidence of resorptions (fetotoxicity) was significantly increased and
the pregnant females gained significantly less weight during pregnancy 1n
mice exposed on days 3 to 6 and 11 to 14. Maternal weight gain was also
decreased in ratss but no fetotoxicity was observed. The authors stated that
the lack of teratogenic effects compared to soms previous studies may be due
to the predictability of the noise stimulation used. More varied noises may
produce greater stress. A second experiment compared the rate of spontaneous
malformations in mice in noisy versus quiet living quarters during days 1 to
18 of gestation. The quiet quarters had A-we1ghted noise levels of 30 to 45
decibels, due to the normal activites of the mice. The noisy quarters had
noise levels of 50 to 60 decibels, from routine husbandry activities of ani-
mal care personnel. The incidence of malformations was not decreased In the
quieter quarters, but maternal weight gain was significantly reduced in quiet.
The authors suggested maternal weight gain reduction may have been due to
other factors related to the quiet quarters themselves.
Since other stressors are often cting along with noise, M.C. Busnel and
Molin (1978) studied the reproductive and fetal effects of noise alone and of
noisa plus 2 other stressors (vibration and crowding in mice). These studies
wer<» continuing at the tima of publication, so that the results must be
considered preliminary. The investigators also wanted to determine whether
the results were due to direct effects on the fetuses or due to the indirect
effects of stress reactions of the pregnant mice. This was done i-iir.g three
combinations of hearing and deaf mice: (1) Swiss albino males mated to female
of the same strain; all adults, and young were normal hearing; (2) Tale hybrid
mice carrying the recessive gene for deafness mated to deaf mut females;
50 percent of the young were deaf and 50 percent had normal he ,.g; (3) nv.le
deaf mutant mice mated to female hearing hybrid, carrying the deer gene; 50
percent of the young were deafc and 50 percent hearing. Each of the three
groups was then subdivided Into three treatment groups—noise stress; noise,
crowding, and vibration stress; non-stressed controls. The noise stress
17
-------
consisted of 1 hour of recorded subway noise of about 105 decibels played 4
times daily. Vibration and crowding were produced by placing 20 females 1n
one cage on a shaking device for 2 hours daily. All treatments were begun
the day of mating and the experiments were continued until each '.nother's
sixth litter, when the females were sacrificed and the fetuses aut.ipsled.
No significant differences were found between experimental and control
animals in the mothers' weights, number of young in the litters, number of
young surviving to weaning, or the sej rati.os of the offspring. Differences
were found in weight gain of the young, time interval between litters, and
the number of fetal malformations between test and control groups. The mean
weight gain of the Utters was 25 to 30 percent lower in the noise alone and
the noise, crowding and vibration groups in the first three litters of the
hearing mothers. Noise alone did not affect the weight of deaf offspring.
The interval between litters was very irregular in all of the stressed groups
compared to the unstressed controls. The incidence of miscarriage, resorp-
tion (absorption of the embryos into the mother's system), and cranial and
spinal malformations were also Increased in the stressed groups. Noise alone
had a smaller effect than in combination with other r.tressors (crowding and
shaking).
BEHAVIORAL EFFECTS
Loud and unfamiliar noises can be very frightening to laboratory animals
as well as other species. Many of the initial behavioral reactions observed
are attempts by the animals to escape. Because caged animals usually have no
place to run to, the stress may be compounded due to the unavailability of an
appropriate (escape) response. Some of tlie behavioral effects in the studies
which follow include altered reflexes, aggression, refusal of food, cessation
of grooming, and impaired learning and physical performance.
In one study, rats exposed for 7 days to sound produced by electric bells
(for 45 minutes to 2 hours per day) became untidy and less active, refused to
eat, and became aggressive (Monaenkov, 1958). Borisova (1960) stated ^hat
white ~ats exposed to 85 decibel noise displayed weakened conditioned reflexes.
Five days of rest were necessary for the reflexes to return to normal.
The effects of noise and crowding on young rats were studied by Groh
(J965). Permanent effects on activity, learning, and soma physiological para-
meters were produced by raising 80 albino rats in two different litter sizes
and under two different sound levels. The rat pups were divided into litters
of either 3 or 13 animals, then randomly assigned to l2Ctating females other
than their own mothers. Half the rat pups in each litter size were raised in
sound-Insulated boxes; the other half were raised in regular wire cages 1n a
noisy (sound level unspecified) aninal room. There were 10 male and 10 female
pups in each of the four groups. After 21 days under these conditions, the
rats wen> weaned and placed, four animals to a cage, in the comncn animal
roon for an additional 21 days, At the end of this period (42 days) measures
were made of body weights, spontaneous activity in an open field test, heart
rate Increases following electric shock, and response latency in a straight
runway at the end of 20 trlal^. Open field measures were repeated at 56 days
and body weights at 57 days. After these tests, relative weights of the adre-
nal gland were measured. Rats 1n large litters weighed less and had larger
adrenal glands, indicating stress effects from crowding. Rats raised in
-------
sour.d-proof boxes learned faster (had lower latencies) in the straight runway
than did rats raised in the animal room. Decreased activity in the open field
test and increased heart rate responses to the sound were more pronounced in
rats raised in large litters in sound-insulated boxes and in those raised in
small litters in the animal room, than were those in the other two groups.
With the possible exception of the cardiac response, all these morphological
ami behavioral changes appeared to be stable. Thus, noisy and crowded condi-
tion* separately were able to produce behavioral changes.
Behavioral changes due to noise were also found in rabbfts. Deryagina
•it al. (197S) noted tbit rabbits that were subjected to 94 to 96 decibels of
sound (at 3000 Hz) 4.5 hours per
-------
e changes in blood lipids
« elevated plasma renin activity
a some adverse reproductive effects
o abnormal behavior (increased aggression, reduced social behavior).
We still do not fully understand the relationships among all these
effects. Furthermore, we must exercise caution in generalizing the results
of these studies, which are mostly sfeort-te»tn, to other situations in which
animals are exposed to noise over longer periods of time.
20
-------
INTRODUCTION
Although sotne studies have been conducted on domestic animals of e\.o-
nomic importance, lack of uniformity^in the measurement and recording of sound
stimuli and animal responses to these stimuli makes it difficult to compare
results across studies. The domestic animals in these studies include sheep,
swine, cows, horses, mink, chickens, and turkeys. Research on noise effects
in domestic animals include studies of hearing, behavioral, and physiological
responses to different noise sources including: aircraft flyovers and sonic
booms, loud noise produced in a laboratory (white noise, music, pure tones,
etc.), species-specific distress calls, exploding paper bags, motorboat noise,
and artificial bird peeps. The behavioral responses observed most frequently
are fright reactions.
Noise, in combination with other environmental factors, has the poten-
tial for producing severe stress in farm animals, which may lead to reduced
quality of some products and adverse economic effects. Parker and Bayley
(1960) noted that the U.S. Air Force has received complaints frooi farmers
about the adverse effects of jet noise on livestock. The studies which fol-
low have attempted to determine whether noise is a significant stressor in
farm animals. No studies on masking were available. Because domestic ani-
mals are more dependent on humans for ?urvival than on intra- or interspecies
communication (which is essential in the wild), masking is not a critical
issue.
HEARING
Auditory thresholds have not been thoroughly studied in domestic animals.
As with laboratory animals, variations in audible ranges in different species
have important consequences for the response to noise.
In one of the few studies on hearing in domestic animals, the auditory
thresholds of 10 Suffolk ev»es were measured in an acoustically insulated room
with a background noise of 26 decibels, by Ases and Arehart (1972). The mea-
suring techniques included changes in EEG (electroencephalogram) patterns and
behavioral responses (ear pricking, head turning, etc.). The auditory thres-
hold was referenced to absolute sound pressure level. The auditory threshold
data for the sheep are presented in Figure 1 and Table 2. The most sensitive
frequency in sheep is about 7000 Hz.
Auditory thresholds for cattle have also been reported (Ames, 1974).
Figure 2 compares the audiograms from 23 cattle and 10 sheep. Mote that these
audiograms have the same general shape as those for humans, except that the
maximum sensitivities of cattCle and sheep are in the higher frequencies.
Bond, et al. (1963) studied the effects of loud noise on the anatoiiiy of
the swine ear. Animals exposed to five trials of aircraft noise of 120 to
135 decibels showed no injury to the gross anatomy or the organ of Corti in
the ear when compared to a control group e'xposed to ambient airfield noise
levels of 70 decibels.
21
-------
ro
20
18
16
vt
I 14
Q
• 12
10
8
3
.1
7000 Hz
7.3 db
JL
I
I I I
I II
.3 .6 1.0 2.0
Frequency (kHz)
6.0 7.0
12.0
(102)
FIGURE 1. Auditory Threshold for Shaop. Plot of minimum auditory threshold with
decibaSs shown as sound pros jura lavel above background (28 dB).
(Ames end Arohert, 1972)
-------
TABLE 2
!V!san Auditory Thresholds In Decibels*-b
(Ames and Arehart, 1972)
Frequoncy (Hz) I Decibels (dS).
100 18.5+5.0
200 18.1+3.3
500 17.1+2.4
1,000 15.9+4.1
2,000 14.5+2.1
5,000 11.8+0.8
6,000 9.0+0.9
7,000 7.3+0.9
10,000 11.5+0.6
11,000 14.9+1.9
12,000 17.3+1.7
a Sound pressure in dB (re 0.0002 dyne/oi^) above background (26 dB).
b Each mean represents 30 observations.
23
-------
30 -
25 •
20
10
5-
I
.2
i
1.0
ZO
i i i i i i
5.0 7.0 10.012.015.020.0
Frequency in kHz
FIGURE 2. Agdioarar for Cattle and Shejp (Ames, 1974)
-------
PHYSIOLOGICAL AND BEHAVIORAL EFFECTS IN FARM ANIMALS
SWINE i
Since farm animals are often exposed to aircraft flyover noise, the
adverse effects of such noise have been of concern to farmers and soma
researchers. A major series of investigations of swine was conducted by
Bond, et al. (1963). These investigations" explored the physiological ana
behavioral effects of noise as a stressor. The parameters measured include
heart rate, water and sodium balance, weight gain, feed utilization, hormonal
secretions, reproductive effects, and general behavioral (fright) reactions.
One series of tests used a telemetric electrocardiograph to monitor each
pig's heart rate in an acoustical chamber. After a constant heart rate was
observed, the experiment was begun. Test recordings of heart rate were made
during 15 seconds prestress (quiet), 15 seconds of noise exposure, and 30-
second quiet recovery period. The noise stress consisted of taped aircraft
at levels of 100 to 130 decibels. The heart rate tests were run at least 4
or 8 times on each animal. Thirteen pigs never exposed to loud noise prior
to the test were used in one series. The results showed that heart rate
increased significantly due to noise and decreased 30 seconds after the noise
stimulus ended, although it had not returned to baseline levels.
The same investigator (Bond, et al., 1963) gave prior exposure to noise
to another group of pigs as part of the study. This exposure consisted of a
tape of jet aircraft noise at 120 decibels, 12 hours daily for 98 days.
Heart rate increased significantly when five of these pigs were exposed to
the same taped jet aircraft noise. Previously unexposed pigs were *ound to
have a greater change in heart rate e.t sound frequencies of 400, 1000, and
2000 Hz (at 110 to 120 decibels). Since the authors state that only small
numbers of pigs were given the various treatments, generalizations about cor-
relations between sound lavel and frequency and degree of heart rate response
must be made cautiously.
Other physiological effects on swine were studied in a review of the
literature on the physiology and behavior of farm-raised animals. Bond (1970)
stated that several days of 93 decibels noise of unspecified frequency resulted
in aldosteronisin (excess secretion of the horraone aldosterone by the adrenal
glands) and severe retention of water and sodium in young, castrated, male
pigs. Aldosterone is a steroid hormone responsible for the body's electrolyte
(for example, sodium, magnesium, calcium and potassium) balance. Excess aldo-
sterone can be induced by stress, resulting in the upset of the electrolyte
balance, which can be manifested by hypertension (possibly due to sodium and
water retention), muscular weakness (due to decreased potassium), excessive
urination, and thirst. These effects are j-ist part of the complex chain of
events triggered by stress in an animal, as discussed in the Appendix. The
review by Bond (1970) also stated that "alarm signals" recorded from pigs
in the slaughter house disturbed the pigs more than mechanically produced
sounds, as one might expect.
Besides aldosterone secretion, feed efficiency and weight gain of
fattening pigs due to aircraft noise were investigated by Bond et al. (1953).
Three to five groups of four ^o six pigs each were exposed to recorded air-
craft noise at 120 to 135 decibels 12 hours daily from around weaning to
slaughter at 200 pounds body weight. Each group of pigs included a control
group unexposed to noise. No significant differences between noise-exposed
25
-------
pigs and control were observed with respect to feed utilization, rate of
weight gain, or food intake.
Reproductive effects in swine were studied by exposing three sows to
recorded aircraft flyover noise in an acoustic chamber for 12 hours daily for
three days prior to parturition (Bond et al., 1963). No adverse effects were
observed on either parturition or the young, although the piglets from the
noise-exposed (test) sows were heavier than control piglets. Since the lit-
ters from only 3 sows (22 piglets raistjd) were examined, these weight differ-
ences between the test and control piglets are probably due to individual
differences and not to noise.
Bond, et al. (1963) also studied the effects of sounds of varying fre-
quencies from 104 to 120 decibels (including the recorded squeal of a pig) on
swine behavior. Nursing sows, baby pigs, and adult pigs during mating were
observed to show initial alarm followed by rapid indifference to the noise.
In summary. Bond and co-workers consider that swine are able to tolerate,
and even become accustomed to, noise up to at least 120 decibels. The only
evidence that noise causes stress in pigs is a temporary increase in heart
rate. More research is needed before the true effects of noise on swine can
be determined.
CATTLE
The effects of noise on milk production was studied in 182 milk cow herds
within 3 miles of eight Air Force bases using jet aircraft. In the one-year
study, no differences in milk production were found when compared to herds
which were not exposed to the aircraft noise. Also, no differences were found
between herds close to the end of the runway and those farther removed (Parker
and Bayley, 1960).
Such milk production studies n&y be affected by sonic booms. Casady and
Lehmann (1966) found, over all, few abnormal behavioral isactions in large
animals due to sonic booms. However, they reported that their studies con-
ducted on herds of milk cows at Edwards Air Force Base may have been biased,
.in that the animals used had been exposed to 4 to 8 sonic booms a day for
several years. Therefore, even though the intensity of the booms used during
testing was higher than those the cows heard daily, the cattle may have already
become accustomed to the noise before the actual testing began. Thus, cows
may be able to habituate to certain noises, as was the case for swine.
Bond (1956) in his review of the literature on noise effects of man and
lower animals, stated that the cows exposed to exploding paper bags every few
seconds for 2 minutes during nriIking did not give milk while the sound stimuli
were present. Thirty minutes following the sound stimulation, 70 percent of
the normal milk production occurred. Bond also stated that motorboat noise
produced a decrease in milk production. However, calf and heifer growth was
unaffected by notorboat noise. Bond also reported that observers found a mild
reaction in dairy and beef cattle to only 19 out of 104 sonic booms of 2.6 to
0.75 pounds per square foot. Milk production was unaffected during the test
period. In fact, Bond noted that reactions to low subsonic aircraft noise
were more pronounced than «*ere ijeactions to s,onic boosts. Further, the same
reactions were observed in response to flying paper, strange persons, or
other moving objects. This observation may indicate that such fright reac-
tions occur more strongly when the animal sees rather than hears the object
(Fletcher, 1971).
26
-------
SHEEP
The cardiovascular and respiratory responses of lambs to noise were
ex/mined by Ames and Arehart (1972) by exposing the lambs to three types of
auditory stimuli. The stimuli used were white noise, instrumental music, and
intermittent miscellaneous sounds (IMS), presented at 75 and 100 decibels
sound pressure level. Taped sounds of electric motors, diesel engines, jet
and propeller aircraft, cannons, rain, ,band marches, stadium crowds, fog
horns, fire crackers, roller coasters, and machine guns were 'all used during
the IMS exposure. The total noise exposure per day was 11 hours. Each noise
stimulus had a duration of from 15 seconds to three minutes, with quiet
periods lasting from 1 to 15 minutes between stimuli. The study was divided
into 4 periods: (1) a 21-day quiet control period at a 45 decibel ambient
noise level; (2) a 12-day test period at 75 decibels; (3) a 2-day control
period at 45 decibels; (4) a 12-day test period at 100 decibels. Five lambs,
not previously exposed to noise, were added as nonacclimated controls in the
third period. During the first day of each 12 day test, heart and respiration
rates were measured immediately before each noise exposure, then at 15 minutes,
1, 4, and 8 hours post-stimtflus. Daily readings were then taken during the
remaining 11 days.
Variations in heart rate occurred earlier and were greater for the 100
decibel exposed nonacclimated lambs with all three sound types. Less heart
rate change was observed due to the music exposure than to the other two types
of noise, indicating that music was less stressful. Heart rate increased due
to both white noise and IMS. Respiration rates increased due to the three
types of noise for both acclimated and nonacclimated lambs. The respiratory
responses to noise were highly variable and seemed to depend on sound type
more than sound level. Panting occurred during both imsic and IMS exposure.
Since the responses were less variable after the 10th day of noise exposure
and the preconditioned animals responded differently to noise, acclimation to
noise may have occurred. The physiological responses to noise in this study
indicate that noise acts as a stressor (can increase the levels of ACTH and
other adrenally mediated responses). The responses vary with the type and
duration of the noise stimulus. The results are shown in Table 3 and Figures
3 and 4.
The effect of noise of the growth of early weaned lambs was examined by
Areheart and Ames (1972). In this study, noise-acclimated lambs were sub-
jected to the previously described stimuli (white noise, music, and IMS) at
the same levels (75 and 100 decibels). Their results shown in Figures 5 and
6, indicated that exposure to 75 decibel white noise caused an increase in
the animals' weight gain and feed utilization efficiency as compared to either
the control groups or the groups exposed to white noise and IMS at 100 deci-
bels. This effect was less pronounced with exposure to IMS at 75 decibels,
while music had no effect on growth or efficiency at any sound level.
Interestingly, exposure to musiCj even as loud as 100 decibels, caused the
animals to be more "calm, more docile, and generally more tranquil than other
groups" (Areheart and Ames, 1972, p. 482).
A final analysis of the data (Figures 5 and 6) shows that both the type
of sound and its intensity can significantly.affect the growth of early
weaned lambs. However, since these findings'are based on short-tenn, or
acute, studies, the applicability to long-term, or chronic, exposure condi-
tions may not be possible (Ames, 1978).
27
-------
TABLE 3
Effect of Sound Type and Intensity on Lamb Heart and Respiration Rates8
(Ames and Arehsrt. 1972}
Levefo Types
USASI
Music
75 dB IMS
Heart rate
(beats/men.)
121 +10.8b'x
111.7 +5.6b'y
119.0 +15. 9X
Respiration
Rate
(breaths/min.
43.3 +5.4b'x
61.0 +6.3C'y
65.0 +20.4c'y
100 d3
Acclimated
100 dB
Non-
acclimated
USASI
Music
IMS
USASI
Music
IMS
122.0 +10. 4°' A
116.0 +8.6c»y
123.0 +_14.6X
130.6 +13 .2 C
124.0 +8.3d
121.0 +11.3
62.4 +15.5UfA
44.0 +4.9b
49.0 +13 .3b
39.0 +5.9b
45,0 +5.2b
46.8 +8.3b
a Mean and SD of three observations during 12-day test.
b,c,d These superscript letters differing in a column indicate
significant differences (P<.05) for intensity levels.
x,y These letters, differing in a column indicate significant
differences (P<.05) for types of sound.
28
-------
150-
140-
130-
120-
100-
WHITE NOJSE
1/41 48
2 150-
1 140-1
I 130 J
o
I 120
110
r
8
9 10 11 12
MUSIC
a 100 dB Non-acclimatized
A100 dB Acclimatized
75dB
100-
30 -
V
1 J
1/4 1
\
4
i
3
i i
2 3
i
4
t i
5 6
i
7
I
8
I
0
1
10
11 12
IMS
Hours
678
Days
10 11 12
FIGURE 3. Heart rates of lambs exposed to different sound types aid intensities.
(Ames and Arehart, 1972)
29
-------
I
§
EC
§
I
Q.
3
DC
1/4
80-
70-
60-
50-
40-t
30-
20
1/4
WHITE NOISE
i
4
u
3
MUSiC
Panting *
—j—T—r
10 11 12
0100 dB Non-acclimatized
A100 dB Acclimatized
• 75 dB
I »
4 8
(108)
2 3 4 5 6 7 8 9 10 11 12
Days
FIGURE 4. Respiration rates of lambs exposed to different sound types and intensitisi.
(Ames and Arehart, 1972)
30
-------
0.3S
0.30
_e
a
O
0.25
0.20
Y
Control USASi Music
Sound Type
IMS
FIGURE 5. Average daily gains of early-weaned lambs exposed to different sound types.
(Ames, 1978)
31
-------
0.35
030
IB
O
>.
°3
o
0.25
0.20
45
75 75-100
Levels of Intensity (d8)
100
FIGURE 6. Average daily gain of e weaned Iambs exposed for 12 day periods to
different round intensities (45 dB Control period, 75-1QO dB acclimatized,
75 ard 100 dB non-acclimatized). (Ames , 1978)
32
-------
Arass (1973) also studied the effects of noise on digestive function.
It was found that sheep consumed less food in noisy environments than in
quist. In addition, tha results showed that for IMS-exposed animals, urinary
output was greater than in the controls or the animals exposed to white noise
or aatsic. IMS exposure also increased digestibility coefficients (the amount
of food absorbed by the digestive system as determined by feces analysis),
while music or white noise had no similar effect. It was suggested that
neural and endocrine mechanises are involved, in the reactions-
Studies of netabolisa and ruscen (the first stomach of a "cud-chewing
animal) were conducted by Harbers, et al. (1S75) on four yearling sheep
exposed to noise levels and types similar to those used by Areheart and Ames
(1972). The 7-day noise exposure trials at 75 or 100 decibels were preceded
Sy control trials at a background level of 45 decibels. The animals consumed
less food under all the noise types and levels above background. Mater intake,
urinary output and ret^bolizable errenjy varied with the type (but not inten-
sity) of noise; intermittent nriscellareous sounds (INS) caused increases in
all measures. Digestibility coefficients wen? also higher with IMS than with
the other types and the controls* The highest urinary creatinine (a nitro-
genous waste product, the level of which indicates normal kidney function)
levels were found due to 75 decibel awsic exposure. The IMS and white noise
produced significantly lower values, indicating reduced protein breakdown.
Ruman motility vas rtot affected significantly by the noise, after the initial
15 minutes. The authors conclude that sheep are able to adapt to contitoious
or Intermittent rtoise of 100 decibels or less. No adverse effects were
noteo, and IPS even stimulated digestion. It should be pointed out that this
too Is a short-term study arid was rrat an examination of long-term effects.
However, the results make it clear that noise exposure may play an important
role in changes in digestive efficiency, metabolic balance, and growth rate.
Thus, further research should be undertaken to identify species susceptible
to these effects as well as the physiologic basis for this susceptibility.
Ames (J974) found alterations in gonadotropin (reproductive hormone)
levels in lambs exposed to 75 and 100 decibel noise ^»vels. Ovarian cbnass,
such as increases numbers of corpora lutea, were produced when ewes were
exposed to a 40CO-H2 pure tor.a during proestrus. The ewes later produced
significantly more lambs. The author suggests a hypothalantic effect of no.se,
which alters the gonadotropin releasing factors, resulting in ovarian changes.
Since other stressors, such as heat, shock, and restraint have been
shown to produce undesirable color changes in the meat from cattle and pigs,
Ames (1978) tested the effects of noise stress on lamb meat. The meat from
42 lambs subjected to various noise stimuli was inspected visually and
spectrophotometrically after slaughter. Color changes in the inaat were noted
with 100 decibel white noise and irrtenrittent miscellaneous sounds. These
types of noise *.ere apparently more stressful than music to Iambs4 using the
degree of color change in the ssat ac the criterion.
HORSES
Casaday and Lehsian (1965) /sported some, behavioral effects in race
horses due to jat aircraft flyovers. The reactions included jumping and
galloping around, apparently fright reactions. Such reactions to loud noise
are observed in most species of aninals, although the degree of fright seems
to vary.
33
-------
MINK
Cottereau (1978) stated that he observed little or no effects of sonic
booms on ranch-raised mink in spite of the fact that sore studies have
reported severe reactions. It should be noted, however, that nrink may be
overly sensitive to certain types of other sounds.
In one study (Travis, et al., 1968), 120 mink were exposed to simulated
sonic booms with peak overpressure in t^e hogsing shed decreasing from 2.0
pounds per square foot in the front of the shed to 0.5 pounds" per square foot
in the back of the shed in a smooth gradient. A mean boom frequency of 485 Hz
was used. Litter sizes of boomed mink were larger than those born to non-
boomed nrink. Although the first boom resulted in some apparently curious
emergence from nests, no racing, squealing, or other evidence of panic was
observed. Autopsies of kits which died of natural causes disclosed no dis-
orders which could be traced to booming.
Another study (Bell, 1970) showed little or no response to six sonic
booms in 10 days with reference to nrink bitch behavior during breeding, birth
of kits, or whelping. No cannibalistic behavior toward kits or any other
evidence of panic was observed.
Travis, et al. (1972) exposed mink to real and simulated sonic booms dur-
ing the whelping season in order to study the effects on late pregnancy, par-
turition, early kit mortality and kit weight at 7 weeks. Oiie group was sub-
jected to three real or three simulated sonic booms at a pressure of 290 N/tr?
(Newtons per square meter; approximately 145 decibels), while a control group
was not exposed to any booms. The findings indicate that farm-raised mink
exposed to intense sonic booms during whelping season showed no adverse
reproductive or behavioral reactions.
POULTRY
Stadelman (1958a) held fertilized eggs from white hens 1 to 7 days after
laying and then subjected them to incubation under conditions of noise (over
120 decibels) or no noise (under 70 decibels). The noiss produced inside the
incubation boxes consisted of playbacks of recorded background airfield noises,
and noise from propeller and jet aircraft. Noise was present 8 out of every
20 minutes from 8 a.m. to 8 p.m. each day and from 8 p.m. to 8 a.m. every third
night. The results showed no effects on hatchability of eggs or on the quality
cf chicks hatched.
Vince (1966) exposed embryonic chicks to artificial "peeps" which mimicked
the "peeps" actually esritted by bobwhite quail chicks. The artificial "peeps0
were speeded up or slowed down as a function of the rate of speed at which the
actual peeps were emitted. Three or more peeps per second were instrumental in
causing eggs to hatch whereas less than three peeps per second did not increase
hatchability of eggs.
In another study (Bell, 1910), it was shown that exposure to daily sonic
booms with sound pressures of 0.75 to 1.25 pounds per square foot had no
adverse effects on the hatchability of chicken eggs exposed for 21 days during
incubation. j.
Besides egg hatchability, the effects of noise on hen maternal behavior
have also been investigated (Stadelman, 1958a). Eighteen New Hampshire and
Plymouth Rock hens were observed for broodiness for three days and then divi-
ded into two groups. Broodiness is defined as the cessation of egg laying
34
-------
and the onset of egg incubation. One group was exposed to noise at 120 deci-
bels while incubating 12 hatching eggs each. Hens in the other group were
given 12 hatching eggs each- but were not exposed to sound. In the group not
exposed to sound, all egns were hatched., In the group exposed to sound, all
except one hen stopped brooding within two hours. The exceptionel hen,
although she remained broody, hatched only cne chick from 12 fertilized eggs.
Stadelman (1958a) also reported that recorded aircraft flyover noise at
80 to 115 decibels (played daily from 8^ a.m..to 8 p.m. and from 8 p.m. to 8
a.m. every third night for 5 out of 20 minutes from onset of "brooding until
chicks were 9 weeks old) resulted in no difference in weight gain, feeding
efficiency, meat tenderness or yield, or mortality between noise-exposed and
unexpbsed chicks. !t was noted, however, that the chicks subjected to the
noise were observed and that the presence of the observers could have rendered
these chicks more adaptable to changing situations than chicks raised under
natural conditions.
The effect of noise on broodiness has also been studied in turkeys
(Jeannoutot and Adams, 1961). Seventy-eight turkeys were exposed to record-
ings of low flying jet planes at 110 to 135 decibels for 4 minutes in the
third day of broodiness. This exposure typically resulted in a cessation
of broodiness and a resumption of egg laying. The period between cessation
and resumption of egg laying was shorter than when interruption of broodi-
ness was produced by injections of hormones such as progesterone. In addi-
tion, hens injected with progesterone showed a reduction in egg production
during resumption of egg laying, whereas the noise exposure of broody hens
produced no decrease in egg laying when egg laying was resumed following
sound stimulation.
In another experiment by Stadelman (1958b) 2,400 crossbred meat chicks
were exposed to aircraft flyover noise at 80 to 115 decibels. The chicks
were not exposed to sound until they were 31 days old, at which time they were
exposed for 5 out of every 20 minutes for 4 hours. Chicks were not exposed
to the noise again until they reached 45 days old. The noise exposure sched-
ule above was then reinitiated, with a three-day break due to equipment fail-
ure, until they reached 10 weeks old. There was no difference in weight gain
or feeding efficiency between exposed and nonexposed chicks. Cne chick was
trampled to death when noise was initiated at 31 days and chicks ran away
from the speaker at the end of the cage where the sound level was 20 decibels
lower. The investigators hypothesized that during an actual flyover, the
sound would not be louder at one end of the pens than the other; therefore,
there would be no running from the sound source.
SUMMARY
The effects of noise on domestic animals are not as well-documented as
those on laboratory animals. Nevertheless, there is evidence that excessive
noise could have very disruptive effects on certain normal activities of
animals that are important sources of food. The major observed effects of
noise on domestic animals from the preceding studies are summarized below:
• Initial fright or alarm reactions in'all species
• Significant temporary increases in heart rate in lambs
and pigs
35
-------
• Increased respiration rate in lanfcs
• Decreased milk production in cows exposed to certain
unpleasant noises (rootorboats and exploding paper bags),
but not sonic boass
• Increased weight gain and feed utilization but decreased
feed consunrption, In sheep
• Changes in sheep water intake, urinary output,
metabollzable energy, digestibility coefficients, and
urinary creatinine levels of sheep due to intermittent
miscellaneous sounds (75 and 100 decibels).
• Alterations in ovarian factors and reproductive hormone
levels in lambs
• Ability to tolerate noise levels up to 120 decibsls in
pigs, sonic booms in cows, and 100 decibel noise.or lower
in lambs
• Color changes in lamb meat with exposure to 100 decibels
white noise or IHS
• Inhibiting effects on hen maternal behavior (broodiness)
due to 120 decibels or greater aircraft noise, resulting in
fewer eggs hatched.
Although there is a general trend for domestic animals to be able to
become used to intermittent noises under 120 decibels, this ability has not
been densnstrated with all types of environmental noisa conditions. Poultry
are known to have severe fright reactions to loud noise (Cottereau, 1978),
which could adversely affect egg production. Since noise and other stressors
can produce unacceptable color changes in meat for human consumption frca
cattle, pigs, and lambs, the economic consequences of excessive noise could
be severe. More research on the effects of noise on food quality needs to be
undertaken.
Not only can noise affect the quality of food from domestic animals, but
clso noise has produced changes in growth, reproductive physiology and
behavior, metabolism, and other physiological parameters. These changes
are not all unfavorable, since lambs exposed to 75 decibels white noise had
increased growth rates over 100 decibel noise or control conditions. Since
growth hormone and many other hormones are released during stress (Vander,
et al., 1975), the mechanisms of noise effects on growth are probably very
complex. Ames (1978) suggested a neural response to noise that triggers
endocrine reactions, but more research is needed before these responses are
understood.
36
-------
SECTION in. WILDLIFE
INTRODUCTION5
The wildlife studies discussed 1n this section cover a wide range of
animals, including Insects, fish, reptyc-s, birds, and mammals. Although
many studies have been done on the effects of noise on animaTs, few long-
term studies performed in natural settings exist. Those that are available
are often lacking specific information concerning noise intensity, spectrum,
and duration of exposure. For a discussion of the importance of adequately
specifying the noise exposure and factors related to sound propagation and
detection, see Harrison (1978).
9 The bulk of the studies emphasize behavioral effects of noise on wild-
life, because si-ch effects are often most readily observable (Lee and Griffith,
1978). Although behavioral responses are useful indicators of noise effects
in animals, there is a potential problem in the interpretation of these reac-
tions because it is often subjective. Many species have been studied in depth
for response patterns to noise, as in the Preyer reflex discussed in the sec-
tion on laboratory animals. An important area of noise research in wildlife
that has been neglected is a description of the relative hearing sensitivity
of each of the many wildlife species. This is obviously necessary for evalu-
ating and predicting the effects of various noise levels and types. Table 4,
constructed by Lee and Griffith (1978) from various sources, summ^-Szes some
of the available data on hearing sensitivities in wildlife specier and
humans.
As the table shows, some wildlife species are sensitive to a greater
sound frequency range than humans. The A-weighting scale measures sound
levels by selectively discriminating against certain low and high frequencies.
The frequency of the sound is a determinant of loudness as perceived by the
listener. The A-weighted scale represents a simplification of the response
pattern in humans. Since wildlife species do not have the same response pat-
tern as humans, A-weighting may not be appropriate for many wildlife studies.
Fletcher (unpublished) suggested using the unweighted sound pressure level
until more appropriate scales for animals are determined.
Another potential effect of noise on wildlife is masking. Masking is
interference with communication or signals and is a common problem for humans
as well as wildlife. When masking occurs, the threshold of hearing for a
desired sound is increased due to the presence of an undesired sound. Animals
use auditory signals to evade predators, to locate mates, their young and
prey, and to define territories. Even a wildlife species which is adapted
(behaviorally or physiologically) to loud noise could be adversely affected
if its communications patterns are disrupted.
Masking due to noise has been studied in wildlife by comparing the level
and spectra of (1) the ambient or background noise in the natural habitat,
(2) the offending noise, and (3) the signal or communication. For example,
Figure 7 shows the spectrum of each type of ambient noise in an Australian
habitat (Rennison and Wallace, j.976).
Another neglected area of noise research on wildlife is that of non-
auditory physiological effects. The nonauditory effects have been more
thoroughly studied in humans and in laboratory animals. Many of these
effects involve the startle or stress reactions (increased cortisol levels
37
-------
TABLE 4. Hearing Abilities (Frequencies) of Various Animals as Compared with Man
(Leo and Griffith, 1978}
Species
Lower
Limit
(Hz)
Maximum Upper
Sensitivity Limit
(Hz) (Hz)
Man
'(Homo sapiens)
16
4.000
20,000
Tiger moths If
(Arctildae)
Noctuid moth I/
(Prodenia eviHania)
Butterflies
(38 species) I/
(LepidopteraeT
Long-homed
grasshoppers I/
(Lepidopter3f»T
Long-horned
grasshoppers I/
(Tettigoniidain
Field cricket \f
(Gryllus)
Mosquito 2}
(Anopheles subpictus)
Male Midges 2J
(Tendipedidae)
Invctebrates
3,000
3,000
40,000-80,000
40,000-80,000
20,000
15,000-60,000 240,000
800-1,000 10,000-60,000 90,000
300
150 380
80-800 with
peaks at 125 and 250
8,000
550
I/ Frequencies of continuous tones that stimulate the tympanal organs.
2_/ Frequency response of Johnston's Organ which is located at the base.
JL
38
-------
TABLE 4. (coot.) Hearing AbHities {Frequencies} of Various Animals as Compared with Man
Species
Bullfrog
(Rana catesbeiana)
Starling
(Stumus vulgaris)
House sparrow
(Passer domesticus)
Crow
(Corvus brachyrhynchos)
Kestrel (Sparrow Hawk)
(Falco sparven'us)
Long eared owl
(Asio otus)
Mallard duck
(Anas platyrhynchos)
Bats
(Chiropt&ra)
Rodents
(Rodentia)
Cats
(Felldae)
Opossum
(Didelphus virgim'ana)
Lower ,
Limit 1
(HzJ i
Amphibians
<10
Birds
aoo
<300
300
8,GOO
>10,000
18,000
>8,000
30,000-100,000 150,000
5,000-18,000 &
40,000-60,000 100,000
—
—
70,000
>60,000
39
-------
Leaf noise from
tree motion
Overall
Background
250
500
1000
Frequency in Hz
2000
4000
FIGURE 7. Frequency Spectra of Background Noises and Off-Road Vehicle (ORV)
Noiso in an Australian Habitat (Rennison and Wallace, 1976)
-------
and other sympathetic nervous activity) described in the Appendix. Wild
animals that can survive human encroachment on their habitats have been able
to adapt their behavior patterns and other responses to human civilization.
Busnel (1978) lists examples of animals which have successfully adapted:
rats, mice, crows, pigeons, starlings, and seagulls, all of whom choose to
live near humans to take advantage of the food supply and shelter. Many
insect species, too numerous to mention here, have certainly prospered due
to humans. Some of the "semi-domestic'J, animals, such as cockroaches and
house dice, are pests. Squirrels a.id racoons are considered "pests by some,
because they raid bird feeders and garbage cans. Possibly, the true niture-
lovers. among us would rather have these animals around, since they are inter-
esting and occupy a valuable place in our ecosyst-aiu Many insects, such as
honeybees, praying mantis, and ladybugs (who feec1 on aphids), are more than
just part of our ecosystem; they are highly beneficial.
Although there are species which have apparently adapted to human noise,
these are mainly smaller species living fairly close to humans. The larger
animals that risk becoming endangered, such as bears, caribou, the African
game animals, and eagles, are of great concern to many people today. The
environmental impact studies conducted for the Canadian Arctic Gas Pipeline
are an example of this concern and will be discussed in detail in this
section.
The behavioral responses of animals to noise are related to their reac-
tions to tha humans who are directly or indirectly responsible for the noise.
For example, if an animal sees a person shooting a gun or riding a snowmobile,
it will react to both *"he noise and the person. If the animal is wild, such
as a reindeer, it will be frightened of humans. A domestic animal, such as a
hunting dog, would probably not be afraid of either the person or the noise.
Care should be taken in interpreting animal responses as to whether they are
elicited by the noise itself or by the noise as a signal of another threat.
The wildlife species to be discussed in this section are presented by
major groupings: mammals, birds, reptiles, amphibians, fish, and insects.
MAMMALS
HEARING
Studies on the effects of noise on hearing in manuals are scarce for
wildlife species, but some quantitative data are available on some desert
animals and a few species of marine mammals (Myrberg, 1980).
Aquatic habitats are increasingly being recognized as vital to our eco-
system and are used as sources of food and many raw materials, for recreation
and"transportation, as sites for various industries that need water, and
(unfortunately) for the disposal of wastes. The aquatic environment is a
unique one, containing soira of the most interesting and beautiful of crea-
tures. Of the two basic aquatic habitats, fresh water and marine, the latter
has attracted the most public interest in recent years. This is partially
due to the many still unknown agpects of the.oceans and partially because
salt water covers over 70 percent of the earth's surface (Knight, 1965).
Marine mammals tend to be very sensitive to high frequency sound. The
major sound sensitivity ranges are from 500 Hz to 45 kHz for the seals and
sea lions and from 8 kHz to 145 kHz for the porpoises, dolphins, and toothed
41
-------
whales. The specific animals on which inuch of this information is based
include the harp seal, the harbor seal, the California sea lion, the bottle-
nose dolphin, the harbor porpoise, the common porpoise, and the killer whale.
The most sensitive auditory frequency region for these animals parallels
that of the sounds made by them. These sounds have been of great interest
in recent years especially regarding the dolphins and toothed whales (odon-
tocetes) and the humpback whales. The most studied sounds made by the odon-
tocetes are called echolocation clicks* Echolocation is the location of
distant or invisible objects using reflected sound waves. Another type of
sound, humpback whale songs, are so musical they have been recorded and sold
for recreational listening. These sounds are considered to be a complex com-
munication device which is not well understood.
The acoustical system of marine mammals and other aquatic mammals is
their most important distance receptor system, and it furnishes important
information regarding food, mates, and predators (Myrberg, 1980). Thus,
anything that affects the hearing of these animals has potentially harmful
effects on the species. Myrberg has suggested that excessive ambient noise
may affect both perception and sound production in marine mammals. A further
discussion of these effects is included in the sections on behavior and mask-
ing in mammals.
The world under the sea is not a silent place. Sources of ambient noise
include vocalizations from marine animals, rain, traffic of marine animals,
ships, and other aquatic vehicles, industrial noises, and military noises.
Myrberg (1980) constructed Figure 8 for his review of the effects of noise on
marine life. He stated that the major habitat of the marine mammals is in
shallow, coastal areas; thus, the figure includes noise levels at a depth of
less than 70 meters. (Note: The underwater reference sound pressure in
Figures 8 through 13 and in Table 5, all from Myrberg (1980), is 1 microbar,
which is equivalent to 1 dyne per square centimeter. 0 dB re 1 microbar is
equivalent to 100 dB re 1 micropascal.)
The other group .of wild mammals whose hearing has been studied are the
small desert animals in the Southwestern United States. One of the noisier
human sports is motorcycle racing. Some researchers at California State
University (Gibson, et al., unpublished) became interested in the effects
of motorcylce racing on small desert mammals. Small animals were sampled
both before and after an excessively noisy race, in which A-veighted sound
levels near the pit were intermittently over 120 decibels for ten hours.
Sound levels reached 140 decibels for brief periods. Animals trapped after
the race were bleeding from the ears and nose, indicating trauma to the
auditory system had occurred. The researchers then investigated whether
the noise level inside the burrows of these animals was any lower. Using a
Honda 100 cc motorcycle as the noise source, a special sound probe was
introduced into the burrows. Sound levels inside the burrows were measured
both with the entrances open and closed with sand. Noise levels inside the
burrows were only slightly less.than those outside, so that the animals
were not easily able to escape the noise.
Another study on desert mammals (Bondello and Brattstrom, 1979c) has pro-
duced some evidence that off-road vehicle noise can disrupt the predator-prey
relationship between the desert^kangaroo rat.(Dippdomys desetti) and the
sidewinder rattlesnake (Crotalus cerastes). One behavior of tffe kangaroo
rat when a predator approaches is "sand kicking," i.e., the rat turns away
from the predator and kicks sand in its direction as the rat departs. This
behavior can be elicited in the laboratory either by presenting a rattlesnake
A?
-------
Examples of Biological Sources of Sustained Ambient Noise
A. Croaker Chorus.
B. Croaker Chorus.
C. Sea Trout Chorus.
0. Evening Chorus-Attributed to Sea Urchins
E. Snapping Shrimp on Sponge Bed.
F. Snapping Shrimp on Sponge Bed.
G. Snapping Shrimp on Sponge Bed.
+20 H
II
en
•a
3
CL
0-
20
40-
^^mm'^M.
-60 -
T 1 H I i'Hi 1 T
1
Frequency (KHz)
\ 1 1 in
10
1 — i
i 1 1 in
100
0.01
T TT
I I III"
0.1
FIGURE 8. Shallow water (<70 m), ambient noise (spectrum level). Data have been extracted from
numerous sources and redrawn. (Myrberg, 1980)
-------
visually to the rat or by playing the noise of a crawling rattlesnake (at an
A-weighted sound level of 36 to 38 decibels at 10 centimeters) to the rat from
a tape recording. In this -study the rat was selective, responding with sand
kicks to the sound of the sidewinder but not to the sound of static or a hum.
Two rats out of 14 were selected for their consistent sand-kicking behavior.
When typical dune buggy sounds (95 decibels, A-weighted, at 4 meters) were
played to the rats for 500 non-continuoas seconds (25 seconds on, 5 seconds
off), their hearing acuity was impaired. Ten minutes after the presentation
of the noise dose, the level of the sidewinder noise had to be increased by 0
to 10 decibels before the rat detected it. This corresponded to reducing the
distance in the field at which the rats would be able to detect the rattle-
snake 'from 40 centimeters to 2 centimeters. It took the rats nearly 3 weeks
to recover their original hearing sensitivity. Thus, for nearly 21 days
following the sound exposure, under nocturnal conditions, the rats could con-
ceivably have been approached and successfully struck by the sidewinder
rattlesnake.
MASKING:
Masking refers to noise that interferes with coranunication of auditory
signals. Behavioral changes due to masking nay be the most observable effects
of noise (Lee and Griffith, 1978). Since auditory signals are used in locat-
ing mates, to establish territory, for orientation, migration, catching prey,
sound detection and many other functions, maskin'- could have profound secondary
effects on matrenalian behavior. The irtfjortance of corrcnunication signals has
recently been studied in Old World monkeys (ger.us Macaca). by Brown, et al.
(1978).
Indirect effects of masking may also be produced, due to the fact that
all the animals in a habitat or ecosystem are interrelated. Thus, an animal
that is directly affected by noise ray affect another species, which may at
first appear unaffected. For example, predator-prey relationships between
the wolf and the caribou may be upset by noise connected with construction of
the arctic gas pipeline. Although the wolf population does not seem to be in
jeopardy from noise, the caribou may be affected. If the caribou population
were to diminish due to noise, the wolf population, which feeds largely on
caribou, could also decline (Kucera, 1974).
Doolinq, et al. (in press) hypothesized that one way to predic- the spe-
cies most vulnerable to masking effects is on the basis of the frequency
range of sounds made by the animal. Two groups of mammals which are known
to depend on auditory signals for survival are bats and the marine mammals.
It has been shown that bats can be resistant to masking (Griffin, et al.,
1963). Apparently they can orient themselves so that noise and signals are
received from different angles (signal masking is greatest when noise and
signal are received from the same direction). This ability represents
an adaptive response or coping itechanism.
Masking has also been studied in marine mammals, since auditory signals
are important factors in distance reception, finding food and mates, avoiding
predators, and locating prey. Inhales and dolphins produce many sounds for
these purposes. In order to explore the potential for adverse effects of
masking on marine mammals, the spectra and intensities of the critical sig-
nals, and the spectrum and level of the ambient noise must be determined.
Figure 8 displayed some underwater ambient noise levels. Some data from
44
-------
Myrberg (1980) on potential masking in the sea lion and dolphin are included
1n Figure 9. The figure shows that rain and ship traffic have the potential
to cause masking, although -this has not been empirically demonstrated.
Another way of gauging effects of masking noise is by estimating the maxi-
mum distance at which an animal can detect a sound made by another member of
Its species, under various noisy conditions. Since ambient noise levels in
the sea can be great enough to mask sounds important to marine mammals, a
number of studies have considered the e/fects on signal detection of rain,
ship traffic, and wave action (sea state). Sea states 1 and 2 are calm and
moderate, respectively. Table 5, from Myrberg (1980), gives the estimated
maximum sound detection distances for the common (or harbor) seal (Phoca
vitulina) under different marine ambient noise conditions.
As table 5 shows, rather calm seas, rain, and ship traffic may consider-
ably reduce the distance over which a seal can hear sounds from another seal.
Since irrtraspecies communication is very important to marine marrsTials, more
studies should be conducted on the effects of man-made noises in the sea,
such as those from oil rigs, factories, and ships.
Another study of masking of auditory communications was conducted with
regard to the fine whale. The fine whale reportedly uses 20 Hz signals for
communication over as many as several thousand miles. This whale species
forms social units, or rang? herds, which are apparently spread out over
large areas in the sea. T.ie major underwater sources of noise for these
animals is ship traffic, in the range of 10 to 500 Hz. The investigators,
as reported in the review by Shaw (1978) suggested that this ship noise may
have reduced the whales' communication distance. The long term effects of
such reduction in communication on this species are unknown.
NONAUBITORY PHYSIOLOGICAL EFFECTS
Very little work has been done on the nonauditory physiological effects
of noise on wildlife. However, certain of these effects have been demon-
strated in laboratory animals (see Section I). Therefore the potential may
exist for similar effects in wildlife. The effects that have been observed
in wild mammals include hormonal, metabolic, and reproductive effects. Damage
may be produced through stress reactions, which can be caused by noise as well
as other noxious agents.
A study on the reaction of caribou to noise was done as part of a series
of environmental impact statements on the proposed Canadian gas pipeline.
Calef {T974-) noted that any unfamiliar stimuli, such as human activities, can
disturb physiological functions of these animals. The effects of such dis-
turbances observed in wild and domestic ungulates (hoofed animals) include
elevated adrenocorticoid levels, weight loss, increased disease susceptibility,
and reproductive effects such as lower birth weights, increased resorptions
(fetal reabsorptions) and abortions (miscarriages). Although aircraft flying
more than 500 feet overhead usually do not produce any overt reactions in
caribou, Calef stated that physiological stress responses may still be
induced.
Another mammal for which fchere is limited research on the physiological
effects of noisy human presence is the white-tailed deer. Moen (1976) inves-
tigated the adaptive responses of deer to cold stress during winter, by
observing deer behavior. Between January and early March, deer tend to
conserve thermal and other types of energy by reducing t';eir activity and
45
-------
+50
30
Calfornia
Sea L/on
(Otarid)
Bottlenose
Dolphin
(De'phinid)
03
•a
e
3
£
a.
•a
o
tO
i *iii»
100 150
FIGURE 9. High frequency ambient noise and its probable masking effect on the 'learing
abilities of selected marine mammals whose peak r-nsitivities are found within
that spectrum. Audiograms were redrawn from several authors. The hatched
area is the region chosen to show the amount of masking that would extend
above the arbitrarily chosen level of ambient noise (in spectrum level) with the
critical ratios (CR) provided. (Myrberg, 1980)
46
-------
TABLE 5. Estimated sound-detection distances under different ocean-noise
conditions for tha harbor s;al, Phoca viiutina.
Selected audio-frequency, 9 KHz; audio-
threshold: spectrum level noise ratio
30 dB. Sound-source l.rci (p-p) in dB/
re 1 m (e.g., conspeciflc) » +38 (Myrberg,
1980). *
Most sensitive threshold (decibels/^bar)
Estimated maximum detection distance (meters)
At Sea-State
1 2
-22
1000
-15
500
At Saa-Stats 1
Traffic level
Averace
Most sensitive threshold (decibels/pbar) -19
Estimated maximom detection distance (niters) 750
-14
425
Rain Level
Light Heavy
-3 +9
120
30
47
-------
their metabolic rate. Moen suggests that during this critical period, noisy
snowmobiles and other disturbances may prevent successful energy retention,
resulting in increased deer mortality. Such disturbances may also seriously
affect species that hibernate.
The only physiological study of hibernating mairenals is one concerning
bats (Miline, et al., 1969). Histophysiological changes in the pineal glands
and supraoptic nuclei of the brain were found after the bats were exposed to
an electric bell rung twice daily (6 t£ 7 a.nu and 8 to 9 a.m.) for 7 days.
Until more research is undertaken, the significance of these "fi rtdi ngs is
unclear.
a
BEHAVIORAL EFFECTS
Noise is atost often considered an aversive stimulus, although some types
of sounds actually attract animals. Larg-» animals such as elk, bison, and
cattle are sometimes attracted to trains and have created hazards by walking
onto the tracks. Porpoises are drawn to boats so they can be pushed by the
front wave. They are attracted from a distance by the noise of the propellers
(Busnel, 1978). The acoustic characteristics (level, spectrum, duration, etc.)
and type of ncise source are obviously critical variables for behavioral reac-
tions to noise. The noise sources in these studies on mananals are sonic booms,
aircraft flyovers, electric power lines, vehicles, and construction sites near
wildlife habitats. The presence of humans and/or machines can exaggerate or
otherwise affect an animal's reaction to noisu. In fact, it may be difficult
to determine which affects wild animals more acutely—human presence or noise.
These factors introduce confounding variables in noise effects research-
Studies on wild mammals include species such as house (nice, rabbits, wild
rats, bats, raarine mammals,, wolves, bear, and a number of hooved specie*:
(antelope, caribou, deer, wild sheep, etc). Startle or fright is the iomsdi-
ate behaviors! reaction to transient, unexpected or unpleasant noise in all
these mammals. Fri^ntened mammals often run swzy or interrupt their activi-
ties. For exacqjle, reindeer seem to experience difficulties in herding, due
to the hum of the power lines (Klein, 1971). If noise persists in a parti-
cular area, animals nay leave their habitat and avoid it permanently. The
physiological and ecological consequences could be serious to species survi-
val, if the new habitat has inferior conditions. Kucera (1974) noted that
avoidancs behavior by mammals requires *"he expenditures of excess energy that
is needed for survival. Avoidance behavior usually implies that an animal
Rust find new food sources, watering holes, and nesting areas, all essential
activities for survival requiring energy expenditure.
According to Kucera (1974), other mammalian behavioral reactions to noise
include altered migration patterns, changes in the home range (the region
where an animal usually moves), and the formation of aberrant behavior pat-
terns between specific individuals, such as refusing to or not being able to
mate. '.'
Besides observations in the natural habitat, some studies investigate
wild animals under laboratory conditions. Wi^d rats and mice were subjected
to various noise frequencies (IgO to 25,000 Hz) and sound pressure levels (60
to 140 decibels) by Sprock, et al. (1967). the effects of the noise ranged
from decreased nesting close to the noise source to deaths at the highest
intensities. Not surprisingly, recorded rat distress calls also decreased
the time spent near the noise source by the animals.
48
-------
In another study of this type, confined colonies of wild Norway rats and
house mice were exposed to pulsed ultrasound provided by an ultrasonic gener-
ator for 76 and 81 days respectively (Greaves and Rowe, 1969). After exposure,
the rodents displayed aversion to the sonic field and did not reenter the
testing ground. The frequency, intensity, pulse duration, and length of time
between pulses were not reported, although ultrasound is usually defined as
sound in frequencies exceeding 20,000 Hz. Since rodents can detect very high
frequencies of 1000 to 100,000 Hz (see,Table, 4), ultrasound as so defined is
well within the hearing range of the rat.
Besides laboratory studies, observations can be made on mammals confined
in zoos. The reactions of captive animals may be quite different from those
of the same animals in their natural habitats. Cottereau (1978J stated that
London zoo animals had no overt responses to high level sonic booms. Since
sonic booms are often frightening to wild and domestic animals, it is not
known why these zoo animals did not respond.
Most of the observations of wild mammals have been made in their natural
habitats. Except during rainy weather, the ambient noise levels reported for
wilderness areas on land are often quite low, from 20 to 40 A-weighted deci-
bels (Luz and Smith, 1976; Soom, et al., 1972). Many of these data are from
North American forests. Since the impact of noise varies from one species to
another, the studies below are summarized by species. Seme repetition is
inevitable, since several investigators have observed more than one species
at a time.
Rabbits. A novel but difficult method of observing wild animals is to attach
radio transmitters to them and follow their movements, a method called tele-
metry. Such a study was done by Soom, et al. (1972) to observe the effects
of snowmobile noise on the movement of seven wild rabbits. The researchers
tried to separate the noise effects from the exhaust fumes, lights, the snow-
mobiles themselves, and other confounding variables. The animals had to be
trapped and released after the transmitters were installed in collars so that
handling added another factor to consiaer. The radio transmitters operated
at a different frequency for each rabbit and transmitted over about half a
mile. Signals from the rabbit transmitters were detected at two towers each
with two antennas. Angular positions of the rabbits were determined using
pointer positions on a protractor. Rabbit movement was studied for three
nights before any snowmobile traffic had occurred, and then for six nights
during snowmobile test runs. Observations occurred from 6 p.m. to 6 a.m.
each night. Snowmobile noise was measured near where the rabbits moved at
five different spots in the woodlot, so that the levels were lower than when
snowmobile noise is measured close to the source. Ambient noise levels ranged
from 20 decibels during quiet to 45 decibels due to cars. The 20 minute snow-
mobile runs were made three times hourly for 5 to 6 hours per night. The dis-
tance moved (in feet per hour) by the rabbits and the size of their home range
were calculated as measures of.activity. The results showed that snowmobile
noise tended to increase rabbit movements and to increase their home range
during the snowmobile runs. The home ranges decreased when snowmobiling
ended, but did not return to the presnowmobiling level. Since only seven
rabbits were observed for a ve?y short period in a 14,5 acre wcodlot, it is
not known what the long terra affects of snowmobile noise are on rabbits.
Although the rabbits remained in their habitat, definite changes in movement
were observed.
49
-------
Another field study method was used by Busnel and Bn'ot (unpublished)
in the areas around several airports in France. Small mammals and raptors
are periodically hunted in-these areas to reduce the danger of collisions
with aircraft. The investigators studied the hunting records kept by the
airport administrators and scientists for any effects on the numbers of the
various species. High noise levels of over 80 decibels, A-weighted, are
common around airfields. Although some correlation was observed between a
reduction in the population of hares r»ijd the. opening of Roissy airport (where
the traffic is very heavy), noise was not thought to be a major factor. No
significant reduction in the population densities of either rabbits or hares
was attributed to noise.
in another study (Crummett, 1970) rabbits were repelled by an acoustic
signal produced by a correrarcially available noise production unit. No details
regarding the duration of the acoustic signal were given. However, the alarm
unit produces signals with frequencies of 2,000 to 4,000 Hz. The signals are
amplitude and frequency (nodulated to maximize jamming efficiency relative to
the particular species under observation. The noise unit is designed to
minimize adaptation, as a warning or deterrent, and was reported to be quite
effective.
Bears. Little information is available on the effects cf noise on bears,
except in connection with the environmental impact studies dens for the pro-
posed Mackenzie Gas Pipeline (across Alaska and Canada). A major source of
noise during and aftor pipeline construction would be increased aircraft fly-
over (for surveillance) and construction equipment noise. Such noises may
cause fright or confusion in these species. The noise may disturb bears
during hibernation with a similar loss of thermal energy as mentioned
above in reaard to deer (Alaska. Natural Gss Transportation System, 1975;
Kucera, 1974).
McCourt, et al. (1974) observed that grizzly bears ceased their normal
activities and ran away even when small airplanes flew over at 1000 feet,
indicating a fright reaction. Other observers have noted a variety of reac-
tions by grizzlies to aircraft, suggesting strong individual differences.
Although there are very limited data on the effects of aircraft flyovers on
grizzly bears, repeated flyovers may alter their home range, foraging pat-
terns and breeding behavior. Although no data have been reported on the
responses of polar bears to aircraft flyovers, this species is considered
endangered. It has been recommeded that aircraft not fly lower than 2000
feet over either grizzlies or polar bears (Kucera, 1974).
Wolf and Covot®. Doll, et al. (1973) found that wolves were frightened by
very low afrcraft flyovers of 25 to 100 feet, but flyovers of between 200
and 1,000 feet only seemed to frighten 30 to 40 percent of the solves. It
has been reported by Klein (1973) and Mech (1970) that wolves can adapt to
aircraft noise as long as they are not hunted from airborne vehicles.
The coyote was also discussed in a review of the environmental effects of
high voltage power transmission lines (Ellis, et al., 1978). A coyote family
was observed to be playing and feeding under a conductor with an A-weighted
noise level of 63 decibels. Th$ authors stated that power lines produce a
relatively constant noise of the same volume"that rarely changes abruptly.
The noise produced may be predictable enough (and therefore non-threatening)
to ground mammals, such as the coyote, to allow them to adapt.
50
-------
Hoofed Mammals. The greatest number of noise studies was obtained on this
group, which includes seven different species. Cottereau (1978) reported
that deer near Eg!in Air Force Base showed no response to high level sonic
booms. Hoen (1975) hypothesized that deer would be more susceptible to noise
disturbance during the coldest and snowiest months (January through March).
Since deer try to conserve energy by decreasing activity during this period,
noise disturbance (such as snowmobiles) may cause an increase in activity and
a dangerous energy loss.
Soon, et al. (1972) studied the effects of snowmobile noise on deer
behavior in a 3000 acre swampy area of Wisconsin. The study focused on 140
acres. Radio transuritters were placed on collars on eight captured deer, who
were then released. Six snowmobiles were operated from 1 to 4 hours each
afternoon for 8 days during February and March, around the perimeter and
through the center of the 140-acre tract, where four of the deer lived. No
point in the tract was further than 1000 feet from a snowmobile path. The
deer movements were monitored before, during and after the snowmobile runs.
One of the deer left the area on the first day, but returned tha next. The
snowmobile runs increased deer movement, which may be due to fright reactions.
An obvious difference between sonic booms and snowmobiles in the studies above
1s that with tha latter the machine and the human operator have disturbing
effects in addition to the noise.
Ellis, et al. (1978) reported that reindeer avoid noisy electric powar
line corridors, unlike the coyote observations above. Fear of the power line
structure itself may contribute to the avoidance reaction. On the other hand,
a herd of longhorn sheep was observed sleeping and feeding near a power line
emitting noise at 53 decibels, A-weighted, and elk have been seen raving
through an area with a noise level of 63 decibels, also generated by a power
line. Steady, predictable A-weighted noise levels up to about 60 decibels
are probably not disturbing to many mammals, after a period of desensitiza-
tion. Most of the observations and measurements en power line noise have
been made during fair weather, since rain produces dangerous surges of elec-
tric power and higher noise levels. No information is available on the
effects of these higher power line noise levels on wildlife, nor of the
effects of the electrochemical oxidants and electromagnetic radiation in
combination with the noise.
A few studies of shaep were done in connection with enviromnental impact
studies on the proposed arctic gas pipeline. Oall sheep, which are known to
be very fearful animals, were frightened by the noise from a simulated gas
compressor station (Kucera, 1974). Tha noise level was about 107 decibels 15
fett from the source. The sheep abandoned that part of their normal home
range within a mile of the simulated compressor and exhibited altered beha-
vior patterns during the noise stimulus. McCourt, et al. (1974) and Feist,
et al. (1973) found that helicopter flyovers were even more disturbing to the
sheep than the simulated gas compressor noise. Since Dall sheep are particu-
larly susceptible to disturbance, noise may adversely affect this species.
Pronghorn antelope, unlikel'Dall sr^sp, were not disturbed by helicopter
flyovers at 60 decibels, A-weighted. However, flyovers of 77 decibels pro-
duced strong fright reactions in which the antelope fled (Luz and Smith,
1976). Ths antelope lived in aji area with an ambient noise of 36 to 40 deci-
bels or less. Likewise, moose were frightened by fixed wing aircraft flying
at 200 feet or lower (Kucera, 1974). Canadian musk ox, once considered an
endangered species, seemed to be quite disturbed by snowmobiles and aircraft
noise and were observed to flee or to display aggressive behavior such as
51
-------
butting contests in the summer (Kucera, 1974). Roseneau and Warbelow (1973)
estimated that frequent helicopter flyovers may cause up to a 16 mile shift in
their ?ucisnar range. Nevertheless, there is sore evidence that musk ox can
adapt to aircraft noise. For example, Fletcher (unpublished) reported that
little or no reaction to airplanes was observer in musk ox living near air-
fields. Again, some animals seem to adapt to noise that is predictable and
unchanging.
The last hoofed mammal to be included ip this section is the caribou,
which has been the subject of a number of environmental impact studies.
Caribou can tolerate blasting noise in winter if they have not been under
hunting pressure, which would make then more nervous. Caribou also tend to
be more easily disturbed when they are in nit or during the fly season
(Jakimchuk, et al., 1974). Roughly 30,000 caribou were observed fleeing from
a helicopter which flew over at 500 to 1,000 feet. McCourt, et al. (1974)
found that caribou avoid gas compressor stations and may use less of their
habitat within 1 1/2 miles of a station. Since caribou have historically
been insulated froiti noisy human activities, care must be taken not to create
too much stress in the herds. During rut, the animals' maternal or mating
behavior could become abnormal (Kucera, 1974). Other vital behavior patterns
could be jeopardized at other times. Caribou, like Dall sheep, are a fragile
species that may be susceptible to noise effects.
Bats. Noise can produce avoidar.ce reactions in bats. A high frequency sound
(4000 to 15,000 Hz) produced by twelve adjustable dog whistles was used to
drive 500 to 1000 bats from a nuclear power station (Hill, 1970). Since the
bats were able to escape the noise, damaging effects were avoided.
Whales. Several types of whales are currently endangered. Thus, the adverse
effects of noise on whales must be considered in the context of species sur-
vival. Cummings (1971) reported that underwater projections of recorded
killer-whale sounds Caused migrating gray whales to reverse their direction
of movement. Similar recordings were used by Fish and Vania (1971) to pre-
vent movement of white whales into an Alaskan river during the tice that red
salmon fingerlings were migrating to the ocean. Pure tone stimuli at 500 and
2,000 Hz and random noise in the baid from 500 to 2,000 Hz were then projected
with the same intensity and the same on-off times as the killer whale sounds
in the gray whale study above. These sounds also kept the white whales from
moving up the river. These studies have shown that soma sounds can temporar-
ily influence whale movement during migration. It is possible that serious
consequences wo-ild result if whales are repeatedly disturbed by noise during
migration. More research is needed on these effects before conclufions can
be drawn.
SUMMARY
Hearing studies in marine mammals have involved determining their audi-
tory sensitivities, as well as describing the importance of hearing in finding
food, mating, avoiding predatory, and in distance reception. Potential masked
thresholds are provided for several types of'marine manuals (sea lions, dol-
phins, and seals) with respect to various ambient noise levels. Studies in
small desert animals observed damage to the auditory system due to motorcycle
noise, as well as tenporary hearing loss in kangaroo rats exposed to recorded
52
-------
dune buggy noise. The nonauditory effects of noise reported in mammals
include possible reduced energy conservation in white-tailed deer due to
snowmobile noise and histoptiysiological changes in the brains of bats exposed
to an electric bell.
Most noise studies in wild mammals have recorded behavioral reactions,
some of which are as follows:
• Startle or fright reactions of «many species to noise
• Avoidance behavior, such as reindeer avoiding power lines
• Temporary effects cf recorded killer whale sounds and other acoustic
stimuli on gray and white whale migration.
BIRDS
HEARING
Marler et al. (1973) studied noise-induced hearing loss and potential
masking effects in male canaries. White noise at B-weighted levels of 95 to
100 decibels was broadcast for 40 or 200 days after hatching,, and the vocali-
zations of birds raised in these conditions wera compared to those of birds
surgically deafened at birth. The 40-day noise exposure was found to produce
about 20 decibels of permanent threshold shift (PTS) and the 200-day exposure
about 50 to 60 decibels of PTS. In the first season, vocalization of canaries
exposed for only 40 days was significantly better than that of birds exposed
for 200 days, which performed as pocrly as the surgically deafened group-
However, in the second season of song development the 200-day exposure group
performed not significantly differently from the 4C-day group.
MASKING
The possibility that excessive noise interferes with bird communication
and acoustic signal detection has also been considered. Social birds live
under noisy conditions produced by their own species. Adelie penguins, fla-
mingos, ducks, and geese are able to communicate over the noise of the colo-
nies with no apparent adverse effects; the same is true for jungle species.
These species seem to be able to discriminate among sound stimuli, so thit
communication is not disrupted. Potash (in press) reported that when Japanese
quail were isolated from their mates, they increased the frequency of their
"separation calls" when ambient A-weighted noise levels were increased from
36 to 63 decibels. The increase in the frequency of the calls improved the
probability of communication. Hence, masking tray not be as severe in natur-
ally noisy habitats, unless the noise greatly exceeds the ambient noise
levels. Apparently, each bird species has a different tolerance for noise
(Busnel, 1978). However, Thorpe (1969) identified potential ecological
effects of masking in birds. He suggested that increased background noise
may mask signals that influence such processes as spacing to obtain optimum
population densities in an area, nesting and care of young, and detection of
prey or escape from a predator.
53
-------
NONAUDITORY PHYSIOLOGICAL EFFECTS
Most of the studies on the effects of noise on birds concern bird beha-
vior; few are on physiological effects. The immediate overt response to
noise In birds, as 1n other animals, 1s startle. Startle responses Involve
some aspects of the stress reaction, affecting heart rate and other parameters
discussed In the Appendix to this report. Thompson, et al. (1968a) telemetri-
cally recorded the heart rate response^pf starlings to various meaningful
sounds. Distress calls produced by physically restrained .starlings produced
high heart rate acceleration and slow habituation to the sounds. Escape calls
of starlings subjected to avian predators also caused slight heart rate accel-
eration and habituation after two or three trials. Likewise, a human voice
produced increased heart rate and required two or three exposures before habi-
tuation occurred. Feeding calls, however, produced the mildest reaction, in
that a negligible heart rate acceleration occurred and habituation occurred
after approximately one exposure. The starlings appeared to be able to dis-
criminate among sound stimuli and react to each sound individually.
Thompson, et al. (1963b) also found that the normal heart rates of wild
starlings were elevated during the day relative to night heart rate values.
The birds studied were housed individually 1n acoustical chambers wherein
natural day and night lighting regimes were simulated. Starling distress
calls were used as an acoustical stimulus. Starlings are normally a~tive dur-
ing the day, and initial heart rate responses to 10 seconds of the auditory
stimulus during the day were significantly different from baseline heart rate.
Although the same stimulus produced an initial, slow increase of heart rate at
night, the decrease to baseline was slower than during the day. When starl-
ings were tested individually, the initial response was less dramatic and the
decrease in heart rate to baseline faster than when the birds were tested in
groups of five. Seemingly, a "flock effect" was operating, in that responses
of individual starlings were influenced by those of the group (Fletcher, 1971).
Regarding reproduction, there is speculation about the effects of trans-
mission line noise, since many birds nest in or near the towers, which can
have A-weighted noise levels of over 60 decibels when it is raining. Lee and
Griffith (1978) reported, in their review of the effects of power line noise,
that 37-nrillisecond sound bursts of 80 decibel noise (at 100 to 8,000 Hz) for
2 hours increased Japanese quail egg hatching time by 10 percent. Effects on
the hatchlings, if any, were not reported. More research is needed before
the true effects of power lines on bird reproduction can be determined.
BEHAVIORAL EFFECTS
The studies or observations on bird behavior can be divided into four
types: (1) the use of noise to repel unwanted birds from a certain area; (2)
the effects of aircraft flyovers, sonic booms and other environmental noises;
(3) attraction of birds to noisy areas; (4) noise-induced changes in repro-
ductive behavior.
Many of the studies on using noise to rid areas of avian pests involve
starlings. Some of the most effective noise? are high-intensity (not defined)
recordings of the species' own distress calls (Langowski, et al., 1969;
Messersmith, 1970; Thompson, ev al., 1968a; Wight, 1971). However, the same
Investigators reported rapid habituation even to species-specific distress
calls when presented continuously. For maximum effectiveness, intermittent
54
-------
presentation has been suggested. More specifically, the final report of a
Committee on the Problem of Noise (19S3) stated that in order to scare birds
away, a noise level of approximately 85 dB decibels sound pressure level at
the bird's ear was required. The noise used consisted of loud bangs and birds'
distress calls. Birds habituated quickly to the noise and it was recommended
that distress calls be used no more than 2 minutes every 20 to 30 minutes and
only during the day.
The residents of Denver, Colorado used the distress call method success-
fully in dispersing flocks of starlings* by playing records of starling distress
calls for four evenings as the birds arrived at roosts. The recordings con-
sisted of repeated cycles of 30 seconds of starling distress calls played for
12 minutes. Habituation of the birds to the records was not observed, although
some of the residents played them continuously. At least half the population
of an urban area must play the distress call recordings for effective dispersal
of unwanted birds (Pearson, et al., 1967).
Habituation to distress call recordings was reported" by Block (1966). The
distress ca'ils were used to disperse roosting starlings during three series of
treatments in 1962. The number of starlings was reduced from 10,000 to a few
hundred during the experiment; however, the roosts were subsequently reinfested
by a majority of the starlings.
The second type of observation on noise related bird behavior includes
sonic booms, ether aircraft noise, and construction noise. Sonic booms have not
beer found to produce any acute effects except startle in birds (Cottereau,
1978). The responses of wild turkeys to both real and simulated sonic booms
were observed by Lynch and Speake (1978). In their experiment, small radio
transmitters were placed on 20 wild turkey hens. This enabled the researchers
to locate and observe the reactions of the hens and their poults to the sonic
booms which occurred during the nesting and rearing season. The turkeys
stopped their activity during the booms, but resur.ied their normal behavior
after a few seconds. No altered maternal behavior was observed in the turkey
hens due to sonic booms. The investigators concluded that decreased produc-
tivity due to behavorial changes did not occur as a result of exposure to
sonic booms.
Davis (1967) observed the reactions of some ravens in Wales to a sonic
boom. When the boom occurred, three or four ravens that had been cruising
in the area were rapidly joined by others. Within 5 minutes approximately
70 ravens were agitatedly circling; 30 minutes later about 30 ravens were
still flying in the area. In another study, Shaw (1970) reported that adult
condors were very sensitive to noise and abandoned their nests when disturbed
by blasting, sonic booms or even traffic noise. The most deleterious effects
attributed to sonic booms were recent mass hatching failures of sooty terns
in Dry Tortugas, Florida, discussed by Bell (1970) and Henkin (1969). Follow-
ing 50 years of breeding success, 99 percent cf the terns' eggs failed to
hatch in 1969. Extremely low-altitude supersonic flights over the area may
have driven birds off their nests and damaged the uncovered eggs. Similarly,
Graham (1969) reported observations of the destruction cf pelican eggs by
gulls when white pelicans were driven off their nests by sonic booms.
A U.S. Department of Interior report on the environmental impact of the
Big Cypress Swamp Jetport (19691 discussed B-720 jet overflight noise at alti-
tudes of 500 to 5,000 feet over two sites in'the park. Observers reported
that no birds were flushed and no disturbances observed. Noise levels ranged
from sound pressure levels of 75 decibels (with aircraft at 3,000 feet) to
55
-------
96.5 decibels (with aircraft at 500 feet). However, it was also reported
that few birds were in the area at the time and wind effects interfered v/ith
proper sound level readings-.
Lastly, it has been reported that fixed-wing aircraft flying at 5000 feet
have caused Canadian geese a half mile away to be flushed. Yet aircraft as low
as 50 to 100 feet rarely flushed nesting females near airstrips. On the other
hand, helicopter overflights have apparently caused nesting geese to temporarily
abandon their nests, leaving the eggs open tp attack by such parasitic birds as
jaegers and gulls (Jacobson, 1974). Flushing is a common avfan fright response,
which may involve a significant disruption of normal behavioral patterns.
As was discussed in the seciion on mammals, the effects of the noise of
the proposed arctic gas pipeline construction on birds and other animals have
been studied. In a personal communication to Jacobson (1974), Baebe stated
that he had seen Peregrine falcons ignore construction noise, other than
blasting, when it was not near their nests. Jacobson reported (1974), how-
ever, that construction noise had apparently caused six falcons to abandon
their nests. Like flushing, desertion of nests could be a dangerous disrup-
tion of normal behavior, affecting survival.
Since gas compressor stations will be a permanent part of the proposed
gas pipeline, the effects of their noise have been studied separately. Simi-
lar to the Canadian geese responses to aircraft, snow geese, in response to
simulated compressor noise, deserted an area within 3 miles of the noise
source (Golloo and Davis, 1974). The presence of this simulated compressor
station noise resulted in significantly fewer flocks of geese circling and
landing near decoys placed in the area. In general, the geese were observed
avoiding these noisy areas altogether. Thus, it is suggested that the loca-
tion of gas compressor stations near feeding and nesting areas may force the
geese to expend additional energy as they detour around the affected area.
The significance of this disruption deserves study.
The third area of behavioral study in birds involves the attraction of
certain birds to noisy areas. Since birds and other animals living1 near air-
ports are regularly exposed to high noise levels, a number of studies of such
populations have been done. Large birds of prey (raptors) and migratory spe-
cies are very prominent on airfields, such that hazardous collisions between
birds and aircraft are often a problem. It is expected that birds would be
more afraid of occasional aircraft flyovers in isolated and very quiet areas
(Busnel and Briot, 1978), because of the stimulus rarity. The surprising find-
ing of these studies is that many birds are in fact attracted to airport run-
ways, largely because of the abundance of small mammals in these areas, such
as the meadow vole near Toronto International Airport (Brooks, et al., 1976).
Power line towers are other noisy areas to which birds are attracted.
These areas are often used by raptors as nesting sites. As with airport run-
ways, there are usually few people around to disturb them. Transmission line
noise is highest during wet or windy weather, however no significant effects
on birds nesting on or near these towers have been observed, regardless of
weather. Another reason for the attraction to power lines may be that power
line noise serves as a navigational aid. Birds have been observed to use
power lines as travel lanes, but the possibilities have not been subjected to
scientific testing (Ellis, 197811. Lee and Griffith, 1978).
One report of noise adversely affecting"reproductive behavior appeared
in a conservation newsletter (Anon., 1978). Excessive noise near the Hialeah
racetrack during the breeding season of nearby pink flamingos was reported to
have interfered with the birds' mating behavior ""'n 1977. The number of chicks
56
-------
produced was lowered as a result. The following year, the racetrack was
closed during the March/April breeding season, but no report on the change in
the number of flaningo chicks produced has been published yet.
SUMMARY
Hearing is a very important sensory modality in birds. It allows birds
to find mates, to locate other birds' territories, to detect-warning calls
from other birds, and to catch prey or to avoid predators. Birds, many of
which have hearing sensitivities similar to those of humans, have been demon-
strated to incur hearing loss due to B-weighted noise levels of 95 to 100
decibels. Reductions in hearing acuity have been shown to have adverse effects
on vocal development in the canary (Marler, et al., 1973). Since vocalization
is such an important function for so many songbirds, more research on hearing
difficulties created by noise in birds in their natural habitats should be
conducted. These effects on hearing would be equally adverse in birds of prey
or in scavengers (seagulls, pigeons, buzzards), since these types of birds
depend on hearing for survival.
Two nonauditory effects of noisa reported in birds are changes in heart
rate and egg-hatching times. Heart rates of starlings were accelsrated by
meaningful or disturbing sounds, such as the distress calls of other starlings
or human voices. Egg-hatching times were increased in Japanese quail eggs
exposed to 80 decibel sound bursts.
The observed behavioral effects of noise on birds include a number of
fright reactions, altered mating behavior, and attraction to some noisy areas
(apparently for reasons not related to noise exposure). The fright responses
of birds may involve flushing, or the more serious desertion of nests, which
may result in eggs not hatching. High noise levels during the breeding season
of a colony of pink flamingos reportedly adversely affected the dating behavior,
resulting in fewer chicks one year. Predatory birds are often attracted to
noisy areas around airports or po^er lines. Although there are probably fac-
tors other than noise attracting the birds (such as fewer humans and more prey),
there are no reports of harm tn these birds by the noise.
REPTILES
HEARING
In reptiles, it has long been thought that chemoreception (the reception
of chemical stimuli) and sight are much more important senses than hearing.
Many reptiles cannot even produce sound (Lee and Griffith, 1978). However,
certain desert reptiles are quite sensitive to low intensity sounds, espe-
cially in the spring and fall (Bondello, et al., 1979). Hearing seems to be
an important sense for these reptiles.
The desert iguana, Pipsosaurus dorsal is, has hearing that is most sensi-
tive in the 900 to 3000 Hz range. The adverse auditory effeccs of noise from
offroad vehicles (ORVs) were investigated in this species by Bondello (1976)
using a recording of motorcycle noise played at an A-weighted level of 114
decibels. Bondello subjected one group of 12 iguanas to this noise under
57
-------
laboratory conditions for 1 hour, another group of 12 for 10 hours, while a
final group of 12 served as controls. The iguanas' hearing was then tested
immediately after the noise exposure and again 7 days later. Hearing was
evaluated by measuring the cochlear potential by means of an electrode
implanted at the round window of the ear.
Hearing was found to be poorer in the test immediately following expo-
sure, indicating a temporary threshold shift had occurred. Both exposure
times, 1 and 10 hours, produced a reduction in hearing acuity that was mea-
surable on day 7. A 10-hour exposure "induced a threshold shift as high as
30 decibels at 1,000 Hz, which coincides with the animal's most sensitive
frequency. The final results indicated that at 114 decibels, a "destructive
dose" (where the recovery time exceeds 7 days) was less than 1 hour. It was
observed that the normal operation of ORVs generates sound intensities greater
than 114 decibels, with cumulative durations greater than 1 hour. Because ORV
rallies, contests, and meets are held in areas where wildlife reside, the
operation of such vehicles may pose a threat to some desert wildlife.
A more recent study by Bondello, et al. (1979) demonstrated hearing loss
in seven lizards exposed in the laboratory to tape-recorded typical dune buggy
sounds. The lizards were Uma scpparia (Mojave fringe-toed lizard), which live
in or near eolian sand dunes. The noise dose was administered for 8 minutes,
30 seconds at an A-weighted sound level of 95 decibels (100 decibels sound
pressure level). Exposure was intermittent with a 30-second duty cycle of 25
seconds on and 5 seconds off. The exposure level was representative of a
dune buggy at 5 meters, but is not a maximum level, because dune buggy noise
of 105 decibels sound pressure level at 50 meters has been recorded. The
hearing loss was inferred from decreased amplitudes and increased latencies
of averaged evoked responses (AER) of telencephalic EEGs made using implanted
electrodes. The correct position for recording AER was physically verified
after the animals were sacrificed. Because the animals were sacrificed imme-
diately after the experiment, it was not possible to determine whether the
lizards had experienced a permdnent or tempoi ary threshold shift. Hearing
losses incurred by lizards in the wild were thought to be likely because of
the observed tendency of ORVs to repeatedly traverse the same area, espe-
cially at surh ORV "playgrounds" as Glamis, California. Moreover, intensive
ORV activities in spring and summer coincide with the reproductive season of
all three species of Uma. making secondary behavioral effects of noise also
possible.
AMPHIBIANS
HEARING
As Table 4 shows, the range of hearing sensitivities of the bullfrog
(Rana catesbeiana) is from under 10 to 3000 or 4000 Hz, with its" maximum sen-
sitivity at less than 1800 Hz (Lee and Griffith, 1978). Unlike many mammalian
species (rodents, dogs) which are sensitive to frequencies much higher than
humans can hear, the bullfrog has a much lower range of detectable frequencies.
Auditory sensitivity data*"have also been obtained for Couch's spadefoot
toad (Scaphiopus couchi). which is the subject of the one noise effects study
on amphibians (Bondello and Brattstrom, 1979b). This spadefoot toad has two
areas of maximum sensitivity: a lower auditory frequency range of from 100 to
58
-------
700 Hz, with its maximum sensitivity at 480 Hz, and an uppar frequency range
from 900 to 1500 Hz, with maximum sensitivity at 1400 Hz. The occurrence of
upper and lower frequency .ranges in this species is due to the presence of
two sets of auditory nerve fibers which respond to different frequencies.
Some other amphibians have three sets of auditory nerve fibers, corresponding
to low, medium and high frequencies (Capranica and Hoffett, 1975, as cited in
Bondello and Brattstrom, 1979b). Such specialized development of the amphib-
ian auditory system may indicate the importance of hearing to this group of
vertebrates. *
BEHAVIORAL EFFECTS j
In a recent laboratory study (Bondello and Brattstrom, 1979b), it is sug-
gested that off-road vehicle (ORV) noise may have a negative impact on spade-
foot toad (Scaphiopus couchi) populations because of its similarity to the
sound of thunder. It has been established that spadefoot toads, found on the
fringe of sand dune areas in the U. S. Southwest, can be induced by acoustical
cues from ORV noise to emerge from their burrows during "-the wrong season, when
there is insufficient water. Twenty toads were allowed to burrow in 10 centi-
meters of fine sand within a 15 gallon terrarium. Recorded motorcycle sounds
of 95 decibels (A-weighted) were played for periods of 10, 20, and 30 minutes.
The toads surfaced in response to the sound in the following numbers: from 1
to 7 after 10 minutes (3.3 average; 7 trials); from 4 to 11 after 20 minutes
(5.7 average; 6 trials); and from 6 to 12 after 30 minutes (7.5 average; 4
trials). Ho toads surfaced during quiet control trials. The motorcycle sound
avidently resembles the sound of thunderstorms, which are extremely important
to spadefoot toad ecology, because breeding occurs in temporary rain puddles.
Host of the toads did not reburrow after the end of the sound, which would
increase the Consequences of emerging at the wrong time, since their limited
energy and w&i;er resources are severely depleted by the act of surfacing.
FISH
Since many species of fish are of great practical importance, both eco-
nomically and as part of our food supply, the effects of noise on fish should
be given careful study. Although fish ara not domestic animals per se, among
those species raised for sport and food, there are similar considerations to
those of the domestic maiimals and birds.
HEARING
The auditory system of fish and other aquatic animals is their most impor-
tant distance receptor system,--and it furnishes information on food, mates,
predators, and other factors r'elated to survival (Myrberg, 1980). Fish are
extremely sensitive to low frequency sounds, and this sensitivity is measured
using conditioning techniques (Cottereau, 1978). Hearing sensitivity data for
several marine fishes are give*i in Figure 10 (Hyrberg, 1980).
As the data in Figure 10 show, unlike the marine mammals, most marine
fish are sensitive to frequencies below 2000 Hz. However, fish in the cypri-
nifonn group, which is composed of mostly freshwater species, such as minnows,
59
-------
< +70
•.S
M
JO
'12
•a
10"
CN
d
60
10
Oamsalfish 9 f Squirrelfish
Marine ^"Mammals
California < Bottlenosa
Sea Lion ? Dolphin
! s>
i • Harbor
^xJ ; &3l
/
1 10
Frequency (KHz)
100 150
FIGURE 10. A comparision of hearing curves among selected marine fishes, mttrine mammals, and man.
(Myrberg, 1980)
-------
goldfish, and catfish, are able to detect frequencies from 5,000 to 10.000 Hz.
Only a few eiarlne species, such as herring, can detect sound; in this range.
Marina fish can be grouped accord* rq to their hearing sensitivities. The
group whose peak sensitivity ranges froa /5 tc 300 Hz includes sharks, haddock,
cod, pollock and tcadflsh. These fish ire able to hear sounds froa 10 to 500
Hz. This hearing range Is useful for sharks, because the sounds produced by
their prey are also in this range. The other fish in this croup produce
sounds in this range, so that the hearing sensitivity is important for intra-
speciflc cofflEt'nlcation. The next grodp has'a peak sensitivity range of fron
400 to 800 Hz and includes damselfish, cubbyu, bonefish, blue-striped grunt,
and squirrel fish. These fish -an detect sounds froa about 200 to 1000 Hz, and
are the most numerous fish species inhabiting shallow water areas. Generally,
related species from similar habitats have similar hearing sensitivities
(Myrberg. 1980).
In general, hearing sensitivities sesm to coincide with the acoustic fre-
quencies of vocalizations. The toadfish is an exception to this principle.
The toadfish mating call, or bcatwhistle, has a fundamental frequency which
varies seasonally froai less than-150 to greater than 250 Hz (Fine, 1978).
Auditory acuity in this species is mismatched with sound production in that
the toadfish is more than 20 dB less sensitive at 200 Hz than it is at lower
frequencies (40 to 90 Hz; Fine, 1981). According to Fine and Lenhardt (1980),
this mismatch and other factors such as the short sound transmission distance
(less than 5 or 6 meters In water about a metsr deep) combine to make recep-
tion of the call a vulnerable process.
Although much is known about the hearing sensitivities of fish, very
little is known about hearing loss in fish due to noise. Goldfish were found
to experienca temporary threshold shifts after 4 hours exposure tu intense
noise levels of +49 dB/ybar. Similar results were produced by lower noise
levels in tne lane snapper (cited by Myrberg, 1930). The potential effects of
hearing loss ara similar f» tha effects of masking, for which more studies
are available. These studios are discussed in the next section on masking.
MASKING
As with the marine mammals, fish may be highly susceptible to the masking
of their suditory signals, which are very important for survival. Marine fish
produce a vfriety of sounds, many of which are used for intraspecific commu-
nication, especial!/ regarding reproductive behavior. Detection and locali-
zation of prey are other important uses of sound, such as by sharks. The
varied sounds produced by members of one species of fish (the damselfish)
define the courting males' territories. These sounds may also be used for
attracting mates. Myrberg (1980) points out that sound reception, discrimi-
nation, and localization may be adversely affected by noise.
Popper and Fay (1973) stcte that the few studies which exist on masking
in fish provide only fragmenta/7 data. These experiments are very difficult
to Interpret, since the auditory system of fish is not fully understood.
Moreover, Tasking may be more complex in fish than in terrestrial vertebrates
because of the possible presence of multiple receptor systems.
Some of the potential masking affects'of ambient noise are presented in
Figures 11 and 12, including data on fish with peak hearing sensitivities of
75 to 300 Hz in Figure 11 and those with peak sensitivities of 400 to 800 Hz
in Figure 12 (Myrb^rg, 1980).
61
-------
+50-1
30-
S
10-
0-
10-
a.
o
CO
30-
-50-
Pollock
Sea State 2 —'
Sea State 1
100
1000
Frequency (Hz)
3000
FIGURE 11. Low frequency ambient noise and its probable masking jiffect on the hearing
abilities of selected marine fishes, whose peak sensitivities are found within
that spectrum. The four audiograms shown were determined either totally,
or partially, in the field. The hatched area is the region chosen to show the
amount of masking that would occur above the arbitrarily chosen spectrum
levels of sea state (f 2) and traffic noise (light) for those species possessing
the critical ratios (CR) as given. (Myrberg. 1930)
-------
+40 -i
20 -
I o
u
i
•a
S" 20
CL
I
5 40
-60
Oamsalftshes
5SPP.
aoi
Frequency (kHz)
10
FIGURE 12, Low frequency ambient noise and its probable masking effect on the hearing abilities
of selected marine fishes, whose peak sensitivities are found within that spectrum.
The hatched area is the rejjion chosen to show the amount of masking that would
extend above the arbitrarily chosen level of ambient noise (in spectrum level). The
ambient chosen was offshore the island of North Bimini, Bahamas where all the
species reside. Audiogranrs were selected from various authors. (MyrHerg, 1980)
63
-------
Another way of assessing the effects of masking is to determine the
effects of various ambient noise levels on the sound detection distance.
Table 6 (from Myrberg, 1980) shows this for two different sea state? and
three different traffic levels, showing, in general, shorter detection dis-
tances for higher ambient levels. The sound source levels used are those of
other members of the same species or those of the prey (in the lemon shark).
NONAUDITORY PHYSIOLOGICAL EJECTS
Some physiological changes have been noted in fish due to sonic booms.
Sonic booms reportedly produce brief startle responses in fish, with some
changes in heart rate. For example, Myrberg (1980) reported decreased heart
rate (bradycardia) in response to sonic booms. Apparently, this is a coinmdn
fish response to many sounds, such as ship noise.
Sonic booms have also been studied in relation to fish because of pos-
sible adverse effects on the eggs and young (fry or sprat). Some effects were
studied in a number of species, including Chinook salmon, rainbow trout, and
steelhead trout, which are commonly raised in fish hatcheries. Normally
reared trout and salmon eggs were exposed, 6 to 8 days after they were ferti-
lized, to sonic booms ranging from 0.89 to 4.16 pounds per square foot (approx-
imately 170 to 190 decibels). Exposure to the booms, at that stage of develop-
ment, did not increase mortality rates. Similarly, 8-ircb rainbow trout were
exposed to a 1.90 to 2.44 pounds per square foot sonic boom (approximately 134
decibels) while in a 6-foot section of a rearing pond. Although the boom
caused a "slight fright response" in the fish, no significant stress reactions
were observed. In this case, stress was defined as a decrease in plasma osmo-
lality or an increase in either the blood sugar (glucose) or blood cortisol
levels (Rucker, 1973). Because the earliest blood sample in the test was not
taken until 30 minutes after the sonic boom, some of the imrrediate noise
effects may have been missed. More studies on stress reactions in fish are
needed before these findings can be interpreted.
Another study on fish development (Myrberg, 1980) involved controlled
tests of noise on two species of estuarine fish: Cyprinodort varlegatus and
Fundulus similis. Egg mortality, fry survival, and fry growth were compared
in a noisy and quiet tank. Noise levels that were 40 to 50 decibels over
the normal ambient noise of their habitats at low frequencies of 40 to 1000
Hz significantly reduced the viability of the eggs. Noise levels at 20 deci-
bels over ambient noise however did not produce these lethal effects. No
lethal effects were observed in the fry, but growth rates were significantly
reduced. The results are summarized in Figure 13.
Thus, adverse physiological effects seem to pose a threat to fish mainly
in the immature stages, affecting hatchability, growth rate, and development.
However, the noise levels necessary to produce these effects may not occur in
the marine environment with great frequency. Except for some fright or
startle responses, sonic boomsl'do not seem to pose a great threat to adult
fish (Cottereau, 1978).
BEHAVIORAL EFFECTS
Some fish are attracted to and seem to be unharmed by noise. For example,
sharks are attracted to the noise of ships when searching for food. In Venice,
64
-------
TABLE 6. Estimated sound-detectlon-dlstences under different ocean-noise condi-
tions for selected species of marine fiahes.
Conspecific source levels used in all calculations, except for
those involving the lemon shark; audio frequencies selected
from regions of peak energy for the respective sound sources
(Myrberg, 1980).
tn
Species
Eupomacentrus partltus
Qicolor damsel fish
V
. :
llolocentrus njfus
Longipine squ
Opsanus tau
ToaJfRh
frrelfish
Neyap/ion brevlrostris
fernon shark
Sound-Source
Level
(dB//ibar te 1 m)
+ 7
+13
-.35
+30*
Selected
Audio-
Frequency
(Hz)
500
600
'100
300
Audio
Threshold;
Spectrum Level
Noise Ratio
(dB)
23*
23
17*
20
At
Sea
State
1
2
1
2
1
2
1
2
Most
Sensitive
Audio
Threshold
(dO/x/bar)
-12
- 7
-16
- 8
- 2
- 2
-13
-10
Estimated
Maximum
Detection
Distance
(Meters)
9
5
30
12
75
75
150
105
At
Traffic
Level
(Sea
State 1)
Llpht
Average
Heavy
Light
Average
Heavy
Light
Average
Heavy
Light
Average
Heavy
Most
Sensitive
Audio
Threshold
(d3//ibar)
-12 •
« - 3
+ 6
,-13
- 4
+ 5
- 2
- 2
+ 7
-12
- 3
* 6
Estimated
Maximum
Oatection
Distance
(Meters)
9.0
3.5
1.0
20.0
7.5
l.S
75.0
75.0
30.0
130.0
50.0
20.0
* Assumes values as stated in Myrberg (1980).
-------
en
at
Sound Pressure, dB/Microbar
+30 •
*
10-
0 •
30-
Nolje Tank ^^
Quiet Tank ©•"" ""
Biicayna Bay
Sheltered Roglcn
Dopth 30 CM
•50 -1r i|
10 20
Species I j E
Cypnnorfon Noiie Tank
Variagatui Quiat Tank •.
Fundulus Noise Tcnk
Slmilis Quiet Tank
-"\___
N
Depth *,7M *'*••.. *"*••» ^
'••... « *• o
rrequ.ncy (Hz) 10° ^ 10CO
S3 Mortality} 24 HrJ. FfV ^'p'oft 24 Hn.\ \ Ffv Un9th | FrV WaiSht
~ Sienificant Difference ~+ -^JJ,,0'^ ~> Significant Diff.renc.
IS Dayi
No Significant Difference — >Poit Hatch — > Significant Difference
FIGURE 13. Effects of sustained noise on egg mortality and fry survival and prowth in two specie*
of estuarine fishes (Cyprinodon variegatus and Fundulu» siniilis). Ambiant noiss
portrayed in spectrum levels. (Myrberg, 1980)
-------
where there 1s a high ]evel of motor-boat traffic, no behavioral effects have
been observed on the fish population. It is not known whether the fish in
this area ars deaf (Busnel-, 1978), nor has the distribution of these fish been
surveyed to determine whether certain species have abandoned the noisy waters.
Fishing vessel noise, especially sudden changes in noise levels, can frighten
schooling fish. Such fish were observed to change direction and to dive. Low
frequency noise is usually the most frightening to fish (FAO Fisheries, 1970).
Malar and Kleerekoper (1968) analyzed locomotor patterns of individual
goldfish before and after exposure to a 2,000 Hz sound at varying intensities
30 centimeters from the source. Locomotor patterns of the fish were signifi-
cantly affected above a sound pressure of 2.0 dynes per square centimeter (a
sound pressure level of 80 decibels).
Fine and Lenhardt (1980), in studying the underwater transmission proper-
ties of vocalizations of the oyster toadfish (Opsanus tau), have noted the
particular susceptibility of vocal behavior to disturbance by noise. The male
toadfish is likely to cease its mating call, or boatwhistle, when exposed to
underwater noise. The authors suggest that noise may be capable of disrupting
courtship in the toadfish and in other fishes of more commercial value. They
further suggest that the suppression of calling behavior by noise indicates
that potential to cause deleterious biological effects, and should be inves-
tigated in freshwater and nearshore marine systems.
SUMMARY
Hearing is one of the most important senses in fish. It is used as a
distance receptor system, to find prey or avoid predators, to locate mates,
to define territories, and in a variety of communications both between and
within species. Most marine fish are sensitive to frequencies below 2000 Hz,
the peak areas of sensitivity being from 400 to 800 Hz in the cod and haddock
and from 75 to 300 Hz in the lemon shark. An exception to this trend is the
herring, which can detect frequencies from 5,000 to 10,000 Hz. Many more
freshwater fish, such as minnows, catfish, and goldfish, are able to detect
these high-frequency sounds. If peak auoitory sensitivity is mismatched with
the acot'Stic frequency of vocalizations, as in the oyster toadfish, communi-
cations may be particularly susceptible to disruption.
Temporary threshold shift (TTS) due to laboratory exposure to high noise
levels has been reported in the goldfish and the lane snapper. Reported non-
auditory physiological effects include decreased heart rate in response to
sonic booms (a typical fish response to sound), slight startle reactions to
sonic booms, significant reductions 'in growth rate of fry, and reduced egg
viability in fish raised in tanks with noise levels 40 to 50 decibels ever
their usual ambient noise levels. Noise seems to be more capable of physio-
logical harm to eggs and fry than to adults. Changes in movement pstterns
in goldfish due to various noise levels have been noted, and the male toad-
fish has been found to cease its mating call when exposed to underwater
noise.
On the question of masking effects, Myrberg (1980) stated that fish are
vulnerable to these effects due. to the importance of sounds in the marine envi-
ronment. Moreover, the ambient noi>e levels in the sea (which can be quite
noisy due to shrimp, bad weather, and ship traffic) may degrade the communi-
cation abilities of fish. Sound detection distances were estimated to be
ccnside.-ably reduced due to heavier ship traffic and waves. Interruption
67
-------
of intra- and interspecies communication in fish has the potential of adversely
affecting their reproductive behavior patterns, detection of prey, and a vari-
ety of other factors necessary for survival.
INSECTS
Since many of the hundreds of thousands of insect species are considered
pests, some of the noise effects literature emphasizes the use of noise as an
aversive stimulus to repel or to kill insects. Nevertheless, all insects are
beneficial to some extent, in that they serve as food for other animals. Many
species are essential because they eat other insects (ladybugs, praying mantis,
and dragonflies), because of their role in pollination (honeybees), or are
desirable because of their great beauty (butterflies, scarab beetles). Thus,
human efforts to eradicate or limit the more harmful insects must not be so
overzealous that they kill off the beneficial species.
HEARING
As Table 4 shows, insects such as some of the moths can detect frequen-
cies from 20,000 Hz to over 200,000 Hz, whereas the mosquito cannot detect
sound over 550 Hz. The great variation in hearing acuity among the seven
insect species listed in the table (out of over one million species) indicates
that generalizations about the effects of noise on this large group of inverte-
brates are not feasible. Ho studies on hearing damage due to noise in insects
are available.
NONAUDITORY PHYSIOLOGICAL EFFECTS
The majority of studies on the effects of noise on insect physiology seem
to be related to reproduction and development. The effects of noise on larval
growth might be used in controlling harmful insect populations. Two investiga-
tions involved exposing Indian-meal ...vCh larvae to sound in order to interrupt
development. The number of emerging adult Indian-meal moths was reduced by 75
percent, after the larvae were exposed to 120 to 2000 Hz sound (sound pressure
levels unreported) for 4 days (Kirkpatrick and Harein, 1965). No such effects
were produced in a similar study by Lindgren (1969), using a variety of noise
frequencies and intensities on Indian-meal moths and flour beetles. The fol-
lowing pure tones were used: 70 Hz at 110 decibels, 200 Hz at 113 decibels,
1,700 Hz at 134 decibels, 2,000 Hz at 120 decibels, 10,000 Hz at 90 decibels,
20,000 Hz at 71 decibels, and 40,000 Hz with sound pressure level not reported.
Variable frequencies of 180 to 2,000 Hz at 90 to 105 decibels and 180 to 2,000
Hz at 90 to 102 decibels were also used. Insects were exposed during the
latter part of the pupal stage and for 2 to 4 weeks as unmated and/or mated
adults. Very little, if any, effect was noted, with the possible exception of
mated flour beetles exposed continuously to 40,000 Hz. Even though large num-
bers of insects were used in majy replications, effects of sound exposure were
difficult to demonstrate, because of variability in egg production. The
conflict between the data of Kirkpatrick and Harein (1965) and Lindgren (1969)
possibly can be explained by stimulation at different stages of the insects'
life cycles, as well as by differences in the sound itself.
68
-------
A series of studies on the effects of high lev«l noise on the various
stages of the flour moth were described by R.G. Busnel 11978). In these
experiments, all developmental stages (egg, larva, pupa, and adult) were
exposed to noise, in order to ascertain whether any particular stage was more
susceptible than the others. The insects were bombarded with sounds of differ-
ing spectral characteristics as high as 180 decibels sound pressure level for
various lengths of time. Using the selected noise spectra, levels, and dura-
tions, Busnel found that noise was ap ineffective method for deinsectization.
Moreover, it would be an impractical method due to the energy costs alone. The
same conclusion was reached in similar studies by Andrieu et al. (1978), in
which a moth (Ephestia kuhniella) and a beetle (Tribolium confusum) that infest
flour were exposed to sounds at various developmental stages. At 180 decibels
exposure frcm a random noise generator, the plastic box housing the adult
insects was ^nattered, but the Insects were still alive. The noise caused
some damage to Ephestia. including broken wings and loss of scales. Behavior
and motor activity of both adults and larvae were normal.
Besides effects on development, lifespan and egg production in adults
have been investigated. Cutkomp (1969) reported that a 72-hour exposure to
a pulsed sound having a frequency of 50,000 Hz, with 25 pulses per second
at 65 decibels, reduced longevity from 20 to 10 days in corn earworm moths
and H3diterranean flour moth:;. The sound was an aversive stimulus in that
the insects were observed to move away from the sound source. In addition
to longevity effacts, the mean number of eggs per female was reduced 59 per-
cent in the treated relative to the untreated group.
Although many of the insects studied -.ere not very susceptible to high
intensity noise, some species may in fact be toore highly sensitive, as indi-
cated in the longevity studies by Cutkomp (1969). Unless further research is
conducted, the potential utility of exposure to noise in increasing the suc-
cess of agriculture and reforestation efforts will continue to be unknown.
Since insect damage to farm crops can have an extremely negative impact on the
farm economy, research into the effects of noise on genetic or developmental
transformations might be useful in alleviating future insect damage. The
reduction of egg production due to noise exposure is another area for further
study in insect management. Research on the physiological effects of noise on
beneficial insects should also be undertaken in order to avoid population
reductions of the useful species.
MORAL EFFECTS
Certain insects have been observed to be attracted to various sounds.
Mosquitoes in swarms have been attracted by engine noise, and a mechanical
piano reportedly attracted large numbers of mole crickets. The insects seem
to be attracted to these sounds because the frequencies mimicked the females1
mating signals (Busnel, 1978}. Male midges were attracted to frequencies of
125 Hz at 13 to 18 decibels above the ambient noise level. The swarms of
midges circled in an agitated manner around the sound source (Frings and
Frings, 1959). ^ J _ ^ . f. , ,,rt^«\
The effects of pure ton$s on locusts .were described by Shulov (1969).
Although tones of 4,000 Hz at 80 decibels sound pressure level had little
effect on feeding behavior, tones of 1,000, 4,000 dnd 10,000 Hz elicited a
flying response in more than two out of three trials.
69
-------
The opposite effect, cessation of movement, has been observed in honey-
bees -in response to certain sounds. Frings and Little (1957) reported that
frequencies between 300 and 1,000 Hz with levels ranging from 107 to 119 deci-
bels sound pressure level produced cessation of movement for up to 20 minutes.
No habituatlon was observed after 2 months. Experiments by Little (195S)
demonstrated that stimulation with sounds having frequencies from 200 to 2,000
Hz produced cessation of movement in honeybees. Vibration of antennae did not
produce the effect, but vibration on any of the three pairs of legs produced
the "freezing response." Cessation Sf movement was also noted in the Indian-
meal moth in response to loudspeakers, bells, and whistles (Tsao, 1969). In
addition, there was evidence of sex-related differences in the range of 2,000
to 40,000 Hz although the details were not specified.
Further studies on honeybees were in progress when reported by Lee and
Griffith (1978). Honeybee colonies placed directly undsr an 1100/1200 kilo-
volt power transmission line noise source were being compared to colonies
placed farther away. The A-weighted sound levels 15 meters from the power
line were about 52 decibels. Since ambient noise levels in secluded areas
can be quite low (20 to 30 decibels or less), a noise level of 52 decibels
may be significant in comparison to the background. No behavioral effects on
honeybees had been observed since the study began in 1977. Other parameters
being considered were honey and wax production, mortality, swarnring tenden-
cies, and foraging. These beneficial insects are being used as indicator
species to study the effects of noise on other insects.
SUMMARY
Although the effects of noise on relatively fey insect species have
been studied, certain insects seem tc be significantly influenced by sound.
Apoarently some insect species are susceptible to effects on life span,
reproductive capacity, and behavior.
70
-------
SECTION IV. SUMMARY AND SUGGESTIONS
FOR RESEARCH
SUMMARY '
Concluding statements in a report of this length and multitude of topics
should be able to provide concise answers to some of the questions we have on
the effects of noise on wildlife. As In most other research- areas, simple
answers are rarely available. It is especially difficult to predict the effects
of noise in natural animal habitats. It is clear that any adverse effects may
potentially have ecological consequences regarding animal populations, predator-
prey relationships, intra- and interspecies behavior patterns, habitat preser-
vation, and the food chain.
Three major areas of speculation remain with respect to noise effects on
animals: 1) the effects of long term exposure to moderate or intermittent
noise; 2) the probability that wild animals experience the same adverse physi-
ological effects of noise as laboratory (and sons domestic) animals; 3) the
ecological consequences of adverse physiological changes, masking, and altered
behavioral patterns.
As stated earlier, noise effects on animals in the laboratory have been
documented better than in either domestic or wild animals. Of tha four types
of noise effects examined—hearing loss, masking, nonauditory physiological,
and behavioral—the most conclusive evidence has been collected on damage to
the auditory system. The major effects of noise on all threa animal groups
will be summarized by the type of effect.
HEARING
The auditory sensitivities of animals are highly variable from one spe-
cies to another as is evident from Table 4. Many animals can detect much
higher frequencies than humans. One notable exception to this trend is that
many marine fish are most sensitive to low frequency sounds. Auditory sensi-
tivities in the species of interast should be taken into account in the mea-
surement and assessment of noise exposures. For example, the A-weighting
system is based on human audition, and is not necessarily applicable to other
species. Another variable to consider in hearing effects across species is
the relative importance of this sense for survival in each species. For
example, hearing is very important to marine mammals and fish. The marine
invertebrates such as shrimp and sea urchins produce a number of sounds;
however the importance of hearing to these invertebrates has not been con-
sidered (Myrberg, 1980).
Observations on pathological changes in the auditory system due to noise
have been made primarily in laboratory animals, including guinea pigs, mice,
and chinchillas (which are alsJJ raised domestically). Anatocic change-: in the
ear include the destruction of the sensory hair cells in the organ of Corti,
histologic changes in the cochlea (the major hearing structure), and electro-
physiological changes in the form of decreased amplitude of the cochlear micro-
phonic potentials, indicating reduced sensitivity to sound. Blood clots and
bleeding in the inner ear have also been observed. Temporary threshold shifts
(TTS) due to noise have been demonstrated and have been correlated with some
of the electrophysiological changes.
71
-------
Auditory changes representative of hearing damage have been demonstrated
1n canaries (due to 95 to 100 decibel tone bursts) and some small wild mam-
mals, but very little in most wild and domestic animals. The desert iguana
was shown to experience a ITS immediately after exposure to motorcycle noise
at an A-weighted level of 114 decibels.
MASKING
The potential consequences of interference with communication and signal
detection are similar to those of hearing damage, except that, in practical
terras", masking lasts only as long as the noise is present. There is much room
for speculation about masking. Although masking is a demonstrated effect of
noise, the degree of its occurrence and its potential secondary effects on
life functions in natural habitats remain undetermined.
No masking effects studies were located on laboratory or domestic animals,
reptiles, amphibians, or insects. Masking effects have been considered in
wild mammals, wild birds, and in fish. Such animals use auditory signals for
finding other members of their species (offspring, mates, etc), for locating
prey or avoiding predators, for defining territory, for orientation, and in
migration. Marine aniirals use sounds for distance reception as well as for
the aforementioned reasons. Since auditory signals are used for behavior
necessary for individual survival, any inhibition of normal behavioral pat-
terns due to masking may affect survival. The potential ecological conse-
quences of masking are still hypothetical, since no proof of these conse-
quences exists.
One of the mairanalian studies on masking reports that bats seem to be
able to overcome masking by reorienting so that the signal and noise are from
different directions (Griffin, et al., 1963). Hyrberg (1980) has given con-
sideration to masking effects in the marine mammals, such as dolphins, seals,
and sea lions, as well as in fish. He has shown the likelihood that masking
occurs by comparing ambient noise levels and the hearing abilities of the
marine mammals and fish.
NONAUDITORY PHYSIOLOGICAL EFFECTS
There are many complex effects on animal physiology produced by noise,
as summarized and displayed in Table 7. The reader should also refer to the
figures showing neuroendocrine pathways and stress physiology in the Appendix.
Table 7 shows two things: (1) where the gaps are in no'ise research on animals;
and (2) that the studies confirm that many of the physiological reactions to
stress may occur in animals exposed to high noise levels. The major gaps in
research on the nonauditory effects of noise are studies on wild animals of
all types. Another neglected area is that of moderate chronic noise exposure.
Almost all of the data reported here are the result of short term studies with
very high noise levels (over 100 decibels).
BEHAVIORAL EFFECTS
The only animals for which no behavioral studies on noise have been
1 orated are the reptiles. Many of the behavioral effects recorded for many
72
-------
TABLE T. Nonauditory Effects of Noise
Laboratory Animals
Domestic Animals Wildlife
Biochemical Parameters:
Increased, blood sugar
pyruvic acid
LDH (lactic dehydro-
genase)
cholesterol
free fatty acids
trlglycerides
Decreased glutathione
eosinophils
Urinary Parameters:
Increased catecholamines
(epinephrine &
norepinephrine)
No data (in this report)
No data (in this report)
Neuroendocrine System:
Increased cortisol
aldosterone
(adrenoccrticoids)
Enlarged pituitary and adrenals
Increased acetylcholine activity
brain ascorbic acid
ADH (antidiuretic hormone)
oxytoci n
Cardiovascular System:
Increased blood pressure
Increased heart rate
increase aortic atherosclerosis
No data
No effect on blood sugar
in fish (no data on other
animals or other para-
meters)
No data
No data on urinary
parameters
Increased creatinine
Increased urine output
Increased cortisol Increased adrenoccr-
aldosterone ticoids in hoofed
(adrenocorticoids) animals. No effect in
fish
No data Altered brain histology
1n bats
No data
No data
No data
Increased heart
rate
No data
No data
Increased heart rate in birds
Decreased heart rate in fish
No data
73
-------
TABLE 7. (cent). Nonauditory Effects of Ncisa
Laboratory Animals
Domestic Animals
Wildlife
Metabolic Factors:
Lung hemorrhages
Nn data
Decreased body weight
(Chronic noise)
No data
Not applicable
Reproduction:
No data
Ovarian changes
Testicular changes
No data
Persistent estrus
Altered fertility
Lower weight gain
of offspring
Altered Intervals between
litters
Increased resorptions
malformations
Not applicable
Other:
Lowered resistance to
disease
Not applicable
Increased respira-
tion rate
Increased digesti-
bility and feed
utilization
Decreased food intake
Increased body weight
in lambs (at 75 dB,
but not at 100 dB}
No data
Adverse effects on
meat quality
Decreased milk pro-
duction in cows
Ovarian changes
No data
Altered gonadotropin
levels in lambs
No data
Altered fertility
No data
Larger litxers in
mink exposed to sonic
booms
No adverse effects
reported
Increased hatchabil-
ity or no effect in
poultry
No data
*.
Not applicable
No data
No data
Decreased body weight
in hoofed animals
May interfere with
energy conservation
in dae*-
No data
No data
No data
No data
No data
No data
No data
Lower birth weight &
growth of fry in fish
No data
Increased resorptions &
miscarriages in hoofed
mammals
Lethal to some insect
larvae but no effect on
others. Decreased hatch-
ability in quail
Lowered resistance to
disease in hoofed manmals
Broken wir.gs and s ale less
in sone insects
(extreme noise levels)
74
-------
different species can be grouped into the following categories, which are not
nutually exclusive:
1. F.tght, startle or orienting response
•
2. Abnormal behavior patterns
aggression
cessation of normal activities (grooming, eating)
cessation of movement
altered reproductive behavior
0
3. Weakened reflexes
"4. Learning decretsents
5. Avoidance (may involve abandonment of the habitat, change in the
hoo« range, altsre^ migration patterns)
6. No response, habituation, or adaptation
7. Attraction to the noise or the noisy araa
Th* altered behavior of caged animals {laboratory or zoo animals) is con-
founded by the fact that they cannot escaoe noise. Domestic animals may also
be unable to escape a frightening noise. Fright responses, abnormal behavior,
decreased learning, and weaker reflexes have been observed in laboratory ani-
mals due to no?re. Dossfestic animals, such as swine, sheep, and cattle, seem
to be able to adapt to certain noise levels of 100 to 120 decibels (5orJ, et
al., 1963; Harbers, et al., 1975). Poultry r-eea to be especially fearful of
loud noises, such as sonic booms. Maternal behavior in hens (brooding) was
disrupted by aircraft noise (greater than 120 decibels), such that fewer eggs
were hatched (Stadelman, lS58a),
The study of the behavioral effects of noise in wild animals nay also
b£ confounded by huoan presence, since w&ry wild animals are afraid of humans.
Fright reactions In oany forms are alocst universally observed in animals due
to transient, unexpected noise. The tendency of SOSK animals co avoid the
area near a noise source may lead to adverse behavioral changes, such as aban-
doning tht habitat. Avoida.KC behavior has beer, observed in gsese, caribou,
Dall sheep, reindeer, rabbits, and deer (Ellis, et al., 1973; (iollop and Davis,
1974; McCourt, st al., 1974; Sooa, et al., 1972). Another type of avoidance
behavior, altered wig.-ation patterns, has be«n observed in whcles in response
to killer whale sounds (Cunnings, 1971; Fish and Vania, 1971). Both -Hyins
responses and freezing of aoveiwnt have been observed in honeybees, altKrtigh
the significance of these effects !
-------
Besides fright and avoidance reactions, some animals are attracted to
noisy areas. Birds of prey and small maomals are attracted to airport runways,
possibly due to the availability of food. Insects and fish have been reported
to be attracted to various sounds. Less noise research has been done on behav-
ior of fish and insects than of mammals and birds.
SUGGESTIONS FOR RESEARCH
•
Due to the vast number of animal species, priorities must be set up for
studying both wild and domestic groups. Animals on which we depend directly
for food (including many aquatic species) should be a prime area for research,
since definite physiological and behavioral reactions due to nois^ have already
been observed. The study of stress-induced color changes in meat (and other
changes) is one area that should be explored, because of the potential economic
value. Studies on milk production and egg hatchability affected by noise have
yielded conflicting results in the past, and more studies should be done to
resolve these conflicts.
Other priority animals should be endangered species and any species that
seem to be adversely affected by environmental noise. Ore might also add to
tliesa two groups the wilderness species, such as those covered in the arctic
pipeline studies. Even though many of these species are not in immediate
danger, caribou and many other wilderness animals are ccnsi^'-ed to be in
somewhat tenuous positions. Since ecological relationships are so important,
it is of high priority to study certain geographic areas as a whole (as in
the pipeline studies), considering nultiple species and their interrelation-
ships. Areas chosen for such study would be those, for which noise is likely
to be a problem.
Once species and geographic priorities for study are identified, the
research plan should be carefully considered. A combination of field and
laboratory studies will probably produce the best results. Long term studies
of moderate noise exposure are badly needed. Bender (1977) suggests such a
combination research effort, as summarized in Figure 14.
In addition to the studies of the adverse effects of noise, nwch more
research is needed on the hearing sensitivities of various wildlife species.
Better methodologies for studying noise effects also need to be devised, in
regard to field study, signal detection and masking, and hearing sensitivity.
The study of noise as a stressor should be continued, with more erphasls
being placed on the interaction of noise with ether strcssors, such as crowd-
ing, toxic substances, or weather conditions. The nonauditory effects of
noise on wildlife have received very little attention.
76
-------
t» » :
PROJECT DESCRIPTION
NOISE INPUT
WILDLIFE
INVENTORY
EXTENT OF
IMPACT
STATE-OF-THE-ART
INFORMATION
THE MISSING LINK
«
FFFECTS ON
WILDLIFE
o MAGNITUDE
o DURATION
o FREQUENCY
o SPATIAL EXTENT
o NUMBER
o DISTRIBUTION
o DIVERSITY
o ENDANGERED
SPF.CIES
o TOTAL AFFECTED
AREA
o UNIQUE HA3ITATS
WITHIN IMPACT
AREA
o INTERPOLATE FROM
LABORATORY DATA
o DOCUMENTED ACCOUNTS
o SINGLE SPECIE
o ECOSYSTEM
FIGURE 14. Impact Assessment Steps (Bender. 1977)
-------
APPENDIX
NOISE AS A STRESSOR*
The concept of noise as a stressor is basic to understanding the nonau-
dltory physiological effects of noise on animals. Stress is often defined by
the types of responses of the stressed*organ'ism. For example, the pioneering
stress researcher, Selye, defined stress very generally as "the nonspecific
response of the body to .any demand" (Selye, 1976, p. 53). Selye, defined stress
very generally as "the nonspecific response of the body to any demand" (Selye,
1976, p» 53). Selye also distinguishes between responses to a stressor affect-
ing only one part of the body (such as s. minor skin injury) and that which can
affect the whole body (such as prolonged and intense radiation). Responses
of the former type, in one part of the body, are called the local adaptation
syndrome, whereas those of the latter type involving the whole body are called
the general adaptation syndrome (Ss^ye, 1976). It should be clear that, depend-
ing on the type and intensity, the same adverse stimulus may affect either the
entire body or mainly one part. In this context, the nonauditory effects of
noise can be considered whole body stress responses.
For purposes of measurement, researchers may define stress in terms of a
specific response. For example, one such investigator defines stress as a
stimulus that "provokes responses similar to those attributable to increased
levels o* ACTH" (Ames, 1974, p. 317). ACTH is the abbreviation for adrenocor-
ticotropic hormone, which stimulates the adrenal glands to release cortisol
and other corticosteriods such as aldosterone. A similar definition of stress
is anything that causes increased cortisol secretion and increased sympathetic
nervous activity (Vander, et al., 1975).
Selye first described the stress reaction in 1936, using data from labo-
ratory animals subjected to a number of adverse stimuli (toxic drugs, severe
cold, surgical shock, excessive muscular exercise, etc.) This reaction to
acute stress involved three stages—alarm, resistance, and exhaustion. The
alarm stage consisted of changes in normal body functions in order to deal
with the stress. After about 48 hours, some of these physiological functions
returned to normal in the resistance stage. If the stressful stimuli were
continued for a nonth or more, the animals reached the stage of exhaustion,
in which they were no longer able to resist the stress. In this stage, the
initial bodily changes recurred (Selye, 1936).
The physiological responses ta stress described by Selye have since been
well documented in a variety of laboratory animals as well as in humans. The
response of animals to stress is considered to be nonspecific, because a vari-
ety of different stressful stimuli can prod-jce similar patterns of physio-
logical effects characteristic of stress. Nevertheless, different stressors
do have their owr. unique effects and individual reactions to stress can vary
considerably. The same amountIbf the sa.ne stress-'- may even orovoke different
responses in two individuals of the same species (Selye, 1976).
A major explanation for stress having varying effects in different individ-
uals is that stress involves a^number of complax neuroendrocrine interactions.
An understanding of the normal relationships between neural and hormonal
*0ufour (unpublished).
79
-------
pathways is helpful before the basic physiological responses to stress are
outlined. The endocrine system is controlled by neural mechanises, directly
and by negative feedback. 'The direct neural mechanisms consist of substances
(releasing factors) from the hypothalamus in the brain that stimulate the
anterior pituitary to release hormones, which induce various endocrine glands
to release their specific hormones. The levels of these hormones in the blood-
stream also inhibit the rate of th= hypouhalaaric releasing factors and the
anterior pituitary hormones (negative JFeedback). A number of honrones are
controlled by feedback mechanisms alone. Some hormones are controlled by both
feedback and nervous stimulation. Production of insulin and glucagon by the
pancreas is controlled by a feedback mechanism from the amount of glucose
(sugar) 1n the blood. Production of calcitonin (a hormone that lowers calcium
and phosphate levels) by the thyroid is similarly affected by the plasma cal-
cium level. The release of renin by the kidneys and the production of angio-
tensin are controlled by both sympathetic nerve stimulation and by feedback
from epinephrine in the blood. The enzyme renin catalyzes the production of
angiotensin from angiotensinogen (frota the liver). The release of aldosterone
(a hormone causing sodium retention) by the adrenal cortex is regulated by
the angiotensin level and potassium concentration. The release of the cats-
cholamines (epinephrine snd norepinephrine) by the adrenal medulla is con-
trolled by sympathetic neurons (Vander, et al., 1975). Figure A represent? a
summary of the basic neuroendocrine pathways. The feedback pathways are
represented by broken lines.
The word "stress" evokes mostly negative feelings, because of the impli-
cation of stress in some serious human diseases, including heart attack,
atherosclerosis, ulcers, hypertension, and psychological problems. Although
chronic stress may leed to unpleasant consequences, the absence of any stress
whatever may make an animal more vulnerable to adverse conditions. The bio-
logical origin of the stress reaction is commonly referred to as the "fight
or flight" response, which enables an animal to protect itself frosa attack
(from predators, infection, injury, etc). Loud rioise in primitive times was
usually a signal for alarm. In the 20th cantury, however, high noise levels
are often associated with highway traffic, aircraft, machinery in factories,
blasting operations, and a number of other ordinary sources. Although there
may be no reason to fear these sounds, the same primitive physiological stress
reactions may be induced. These "inappropriate" reactions to noise and other
stressors may be the sources of the nonauditory effects associated with chronic
exposure in humans (Holler, 1975; Selye, 1976). Problems due to stress reac-
tions in wildlife (cs in humans and laboratory animals) deserve further study.
The basic stress response model, compiled from several sources (Selye,
1976; Vander, et al., 1975; Holvey, 1972) involves increased sympathetic ner-
vous systera activity and increased cortisol levels. The sympathetic and the
parasympathetic nervous systems make up the autonomic (or involuntary) nervous
system, which controls the cardiac muscle, the smooth muscles of the internal
organs and the glands, and maintains homeostasis. The parasympathetic system
mainly regulates internal body-functions, while the sympathetic systsa is
mainly involved in responding tc stress and other outside influences. Since
the symapthetic nerves affect many body functions, it is understandable that
increased activity in thase nerves can result in alterations in a nusber of
parameters. The increased cortisol level is due to stimulation of the hypo-
thalamus, which causes the anterior pituitary to release more A:TH (influ-
enced by ACTH Releasing Factor), which stisulates the adrenal cortex to
release more cortisol.
80
-------
Ininrt from othv br*n aran. tfraorv raopton. n«9atM Ittdtuck from Titanon* le Mb
Calming Facoar*
TSHRF. ACTHRF. FSH' F.
LHRF. PIF. GHRF
^....-t-
•
—
BRAIN
HYPOTHALAMUS
T
Annrior
Pmiiury
(Admhvpophyia)
*
GH
FSH
LH
TSH
ACTH
Prolactin
„. «
1 "
Porarxx
0 Prtuttarv
(Nturohvpophysii)
AOH »nd
Oxytocn
I
AOH
C'Ytocin
1
MANY ORGANS
AND TISSUES
OVARIES
TESTES
PANCREAS
BR2ASTS
I
Milk
HonWMan.
Plum* tgoKsta
GH
FSH
EitrojB
^' ''fjf tin lit t
•_H
••
„... T.«CTst^r..*
PI»m« Giuocraa
( Prol»e««i
| {
B
L
0
O
s
T
R
E
A
M
Plasrtu CiJcium
P«r«tllvrok)
TSH
L
Cllcitonm "
Eryth^^i^n
ACTH
Conool
Aldoitiron*
Eotrwohrm.
Nor^Mchnn.
PARATHYROIDS
THYROID
KIDNEYS
•
Angmemm.
RKM
Admut
Cotsx
Adrenil
Mvtulte
•
A Syi«pW*t*c
< j SOmvtsion
/ (*-} (MSltx
from onui«
«om«t*r«r|
Prv^an^.'kxfv
\ Syrnpccwtr
«-| Nairan
TSH
ACTM
FSH
LH
GH
AOH
Thwex!
Ait niwu
TSHRF
ACTHRF
FSHRF
LHRF
GHRF
WF
TSH Rctessinq F»a0r
ACTK R»«»tn»5 Fecnjr
FSH Ritasng Ftetnr
LH Rctemn; Facor
GHRF F.cieaun; Factor
Protieen Inftitxtm^ Fscrar
RGURE A. Neuroendocrine Pathways.
81
-------
Cortisol (or hydrocortisone), like the sympathetic nerves, affects
many organs and tissues. Its functions under normal (nonstress) conditions
involve protein and carbohydrate matabolisra, water and electrolyte balance,
muscle tone, and increased gastric secretion. Higher cortisol levels during
stress result in increased protein breakdcwrt, increased blood sugar, electro-
lyte imbalance, and increased vascular activity. Cortisol has sometimes
facilitated learning in laboratory animals through an unknown mechanism
(Vander, et al., 1975). ,
Although cortisol is the major hormone increased by stress, all other
hormones seem to be affected. Other hormones that are increased during
stress are prolactin (induces lactation), glucagon (increased blood sugar and
fatty acids), thyroxine, growth hormone, aldosterone, and antidiuretic
hormone (ADH). Thyroxine controls growth and a number of metabolic func-
tions. The last two increase water retention, whereas growth hormone may
stimulate tissue repair. Hormones that decrease during stress are testos-
terone, estrogen, insulin, LH (luteinizing hormone), and FSH (follicle
stimulating hormone).
Figure B summarizes the major effects of acute stress and lists the
potential effects of chronic stress.
-------
STRESS*
IN ANIMALS
(Physical and/or Emotional)
Hunger
Pain
Heat
Cold
Noim
Defending territory
Running mazst
Fear of human*
Expectation of being handled
Crowding
Noise (anncyano*. frustration)
General Increasa in
Sympathetic Nervous
System Activity
Hvpothatamus •
Anterior Prtucta y
ACTH
Adrenal Gland
Medulla
Cortex
Increased vasoconstriction
in arterias and internal
Epinephrin*
Noreptnephrina
Spaads up;
I no-eased output;
(noaased BP
HEART
Cortisol
Increased alertness
Increased ike«tal muxde contracttity
Decreased GSR (Galvanic Skin Response)
VafOdi!?tion in skeletal muscles
Reduced gastric motility
Increased ventilation (air exchange in li>ngs)
Increased:
Blood coagulability
Trigh/ecrida breakdown (increased fatty acids)1
Giucagcn, growth hormorse. other hormones
Sugar from grycogerjilysi* (liver and muscle)
Circulating catediolaminei (epinephrina.
norepinephring)
Increased coping ability
Electrolyta imbalance
Incressed protein breakdown
Increased liver uptake of amino acids
and conversion to xuQar
Inhibits sugar uptaka and breakdown by
cells except in the brair.
Enhanced vascular activity
Enhanced learning >a laboratory animate
i EFFE
UOTE
EFFECTS OF EXTREME ELEVATION/ .
POTENTIAL EFFECTS OF CHRONIC
MODERATE ELEVATION—*-
Reduced resiitar.ce to dbeaso (decreased anti-
body production;reduced 'inflammatory
response; suppression of eosinophfit)
Hypertension
Atheroicterosjs
Stomach ulcers
Interte-ence with erams cycis
*AI«o known as tita Tght or flight" respons*
FIGURE B. Stress Responses
83
-------
BIBLIOGRAPHY
Alaska Natural Gas Transportation System. Final Environmental Impact State-
ment. Alaska, Canada, U.S. Department of Interior. Washington, D.C. March
Ames, 0. R. Sound stress and meat animals. lr± Livestock Environment: Pro-
ceedings of the International Livestock Environment Symposium, pp, 324-330.
SP-0174, American Society of Engineers, St. Joseph, Michigan, 1974.
Ames, 0. R. Physiological responses to auditory stimuli, pp. 23-45. _In_
Fletcher, J. L. and R. 6. Busnel (eds.). Effects of Noise on Wildlife.
Academic Press, Inc., New York, 1978.
Ames, 0. R. and L. A. Arehart. Physiological response of lambs to auditory
stimuli. Journal of Animal Science 34:994-998, 1972.
Andrieu, A. J., F. Fleurat-Lessard, andR. G. Busnel. Deinsectization of
stored grain by high powered sound waves, pp. 249-265. Ijn Fletcher, J. L.
andR. C. Busnel (eds.). Effects or Noise on Wildlife. Academic Press, Inc.,
New York, 1978.
Anthony, A. and E. Ackerman. Effects of noise on the blood eosinophil levels
and adrenals of mice. Journal of the Acoustical Society of America 27:1144-
1149, 1955.
Anthony, A. and E. Ackerman. Biological effects of noise in vertebrate
animals. Wright Air Development Center, WAOA Technical Report 57-647, 118 p.,
November 1957.
Anthony, A. and J. E. Harclerode. Noise stress in laboratory rodents. II.
Effects of chronic noise exposures on sexual performance and reproductive
function of guinea pigs. Journal of the Acoustical Society of America
31:1437-1440, 1959.
Anthony, A., E. Ackerman, and J. A. Lloyd. Noise stress in laboratory
rodents. I. Behavioral and endoc.'ine response of mice, rats and guinea pigs.
Journal of the Acoustical Society of America 31:1430-1437, 1959.
Arehart, L. A. and D. R. Ames. Performance of early-weaned lambs as affected
by sound type and intensity. Journal of Animal Science 35:481-485, 1972.
Arkhepov, N. S., et al. Biological effect of high-frequency ultrasound.
U.S. Department of Commerce, Jo^nt Publication and Research Service, JPRS
47378, 1969.
ASHA. Proceedings of the 3rd International Congress on Noise as a Public
Health Problem, Freiburg, West Germany. American Speech-Language-Hearing
Association, Rockville, Maryland, 1980.
Bell, W. B. Animal response to sonic boom. Paper presented at the 80th
meeting of the Acoustical Society of America, Houston, November, 1970.
85
-------
Bender, A. Noise impact on wildlife: An environmental impact assessment.
In Proceedings of The 9th Conference on Space Simulation, Paper 14. NASA
TF-2007), 1977. • V
Block, B. C. Williamsport Pennsylvania tries starling control with distress
calls. Pest Control 34:24-30, 1966.
Bonne, B. A. Mechanisms of noise damage in the inner ear. pp. 41-63 In
Henderson, D., R. P Hamernik, D. S. Dosanjh and J. H. Hills teds.). "Tffects
of noise on hearing. Raven Press, New York, 1976.
Bond, J. Responses of man and lower animals to acoustical stimuli. U.S.
Department of Agriculture, Agricultural Research Service, Animal and Poultry
Husbandry Research Branch, Beltsville, Maryland, October 1, 1956.
Bond, J. Effects of noise on the physiology and behavior of farm animi1s.
pp. 295-306. in Welch, B. L. and A. S. Welch (eds.). Physiological Etfects
of Noise. Plenum Press, New York, 1970.
Bond, J., C. F- Winchester, L. E. Campbell, and J. C. Webb. Effects of loud
sounds on the physiology and behavior of swine. U.S. Department of Agricul-
ture, Agricultural Research Service Technical Bulletin No. 1280, 1963.
Bondello, M. C. The effects of high-intensity motorcycle sound on the acous-
tical sensitivity of the desert iguana Dipsosaurus dorsalis. M. A. Thesis,
Biology Dept., California State University, Fuller-ton; 1976.
Bondello, M. C. and B. H. Brattstrom. Bibliography on the effect of noise on
non-human vertebrates. Unpublished report submitted to Bureau of Land Manage-
ment, U.S. Dept. of the Interior, California, 1979.1.
Bondello, M. C. and B. H. Brattstrom. Part I. Tfv> effect of motorcycle
sounds on the emergence of Couch's spadefoot toad, Scaphiopus couchi. 27p.
In Bondellc, M. C. and B. H. Brattstrom. The experimental effects of off-
road vehicle sounds on three species of desert vertebrates. Final Report of
Contract CA-060-CT7-2737 prepared for the Bureau of Land Management, U.S.
Department of the Interior, 1979b.
Bondello, M. C. and B. H. Brattstrom. Part III. The effects of dune buggy
sounds on behavioral hearing thresholds of desert kangaroo rats, Dipodomys
desert i. 61p. In Bondello, M. C. and B. H. Brattstrom. The expert mental"
effects of off-road vehicle sounds on three species of desert vertebrates.
Final Report of Contract CA-060-CT7-2737 prepared for the Bureau of Land
Management, U.S. Department of the Interior, 1979c.
Bondello, M. C., A. C. Huntley.l'H. B. Cohen, and B. H. Brattstrom. Part II.
The effects of dune buggy sounds on the telencephalic auditory evoked response
in the Mojave fringe-toed lizard, Utna scoparia. 31 p. j_n Bondello, M. C.
and B. H. Brattstrom. The experimental effects of off-road vthicle sounds on
three species of desert vertebrates. Final Report of Contract CA-060-CT7-2737
prepared for the Bureau of Land Management, U.S. Department of the Interior,
1979.
86
-------
Borg, E. Physiological aspects of the effects of sound on man and animals.
Acta Otolaryngolica (Suppl.) 360:80-85, 1979.
Borg, E. and A. R. Holler. Noise and blood pressure: Effect of lifelong
exposure in the rat. Acta Physiologica Scandinavica. 103(3):340-342, July
1978*
Borisova, M. K. The effect of noise on the conditioned reflex activity of
animals. Zhurnal Vysshei Nervnoi Deiatel 'nosti im I.P. Pavlova 10:971-976,
1960.
Brooks, R. J., J. A. Baker, andR. W. Steele. Assessment of small man-rial and
raptor populations in Toronto International Airport and recommendations for
reduction and control of these populations. University of Guelph Department
of Zoology, Guelph, Ontario, Canada, 1976.
Brown, C. H., K. 0. Beecher, n. B. Moody, and W. C. Stebbins. Localization
of primate calls by Old World monkeys. Science 201 («57):753-754, 1978.
Brzezinska, Z. Changes in acetylcholine concentration in cerebral tissue in
rats repeatedly exposed to the action of mechanical vibration. Acta Physio-
logica Polonica 19:810-815, 1968.
Buckley, J. P. and H. H. Smookler. Cardiovascular effects of chronic inter-
mittent neurogenic stimulation. In Welch, B. L. and A. S. Welch (eds.).
Physiological Effects of Noise. "Plenum, New York, 1970.
Busnel, M. C. Effects of Noise on the Foetus. Physiological Acoustical Labo-
ratory, 1NRA, Jouy-en-Josas 78, France. (Unpublished paper)
Busnel, M. C. and 0. Molin. Preliminary results .of the effects of noise on
gestating female mice and their pups, pp. 209-248. j_n_ Fletcher, J. L. and
R. G. Busnel (eds.). Effects of Noise on Wildlife. Academic Press, New York,
1978.
Busnel, R. G. Effects of Noise on Insects. Director Physiological Acoustics
Laboratory, INRA, Jouy-en-Josas 78, France. (Unpublished paper)
Busnel, R. G. (ed.). Acoustic Behavior of Animals. Elsavier Publishing Co.,
New York, 1963.
Busnel, R. G. Introduction, pp. 7-21. J_n_ Fletcher, J. L. andR. G. Basnel
(eds.). Effects of Noise on Wildlife. Academic Press, Inc., New York, 1978.
Busnel, R. G. and J. L.. Bnot. .Wildlife and airfield noise in France. In
ASHA. Proceedings of the Thirdl'lnternational Congress on Noise as a PubTTc
Health Problem, Freiburg, West Germany. American Speech-Language-Hearing
Association, Rockville, Maryland, 1980.
*
Busnel, R. G. and A. G. Lehmann. Infrasound and sound: differentiation of
their psychophysiological effects through use of genetically deaf animals.
Journal of the Acoustical Society of America. 6?;.>):974-977, March 1978.
87
-------
Calef, G. W. The predicted effect of the Canadian Arctic Gas pipeline project
on the Porcupine Caribou herd. Chapter 5 in Res. Reports. Vol. IV. Environ-
mental iinpact assessment of the portion of the Mackenzie gas f/ipeline from
Alaska to Alberta: Environmental Protection Board. Winnipeg, 1974.
Cantrell, R. W. Physiological effects of noise. Otolaryngologic Clinics of
North America. 12(3):537-549, August 1979.
Capranica, R. R. and A. J. M. Moffat.* Selectivity of the peripheral auditory
system of spadefoot toads (Scaphiopus couchi) for sounds of biological signi-
ficance. Journal of Comparative Physiology 100:231-249, 1975.
Casady, R. E. and R. P. Lehmann. Responses of farm ar.imals to sonic booms.
Sonic boom experiments at Edwards Air Fores Base. Annex H. U.S. Department
of Agriculture, Agricultural Research Service, Animal Husbandry Research
Division, Beltsville, Maryland, September 20, 1966.
Cotrenittee on the Problem of Noise. Final Report. Presented to Parliament
Juiy 1963. London: Her Majesty's Stationery Office, Cmnd. 2056, 19s db.
net.
Cottereau, P. Effect of sonic boom from aircraft on wildlife and animal
husbandry, pp. 63-79. In Fletcher, J. L. and R. G. Busnel (eds.). Effects
of Noise on Wildlife. Academic Press, Inc., New York, 1976.
Crummett, J. G« Acoustic information denial as a means for vertebrate pest •
control. Paper presented at the 80th meeting of the Acoustical Society of
America, Houston, November, 1970.
Cummings, W. C. Gray whales (Eschrjchtius robustus) avoid underwater sounds
of killer whales (Orcinus orcaJT" Fishery Bulletin 69(3):525-530, July, 197i.
Cutkomp, L. K. Effects of ultrasonic energy on storage insects. Agriculture
Department Cooperative State Research Service, Minnesota, 1969.
Davis, P. Raven's response to sonic bang. British Birds 60:370, 1967.
Deryagina. G. P., T. S. Sinitsina, and T. V. Veselova. Effect of ecoustic
stimulation on lipid metabolism, indices of the blood coagulation, system
and development of experimental atherosclerosis in rabbits. Fiziologicheski
Zhurnal SSSR 62(8):1171-1181, 1976. (English translation)
Doll, D., W. P. McCrory, and j. D. Feist. Observations of moose, v;olf, and
grizzly bear in the NoKhern Yukon Territory. Studies of Larg? Manna 1
Hopulations in Northern Alaska., Yukon and Northwest Territories. Ed. by
McCourt, H. K. and L. P. Hnrstman, Arctic Ga^ Biological Repcrt Series.
Vol. 22, Ch. 3, 1973.
Dooling, R. J., J. A. Mulligan^ and J. D. Miller. Relation of auditory
sensitivity and song spectrum for the common canary. Journal of the Acous-
tical Society of America. (In press)
88
-------
Dor-land's Illustrated Medical Dictionary. 25th edition. W. B. Saunders,
Philadelphia, 1974.
Dufour, P. A. (Informatics, Inc.; Rodcville, Maryland) Noise as a stressor.
(Unpublished paper)
Elbowicz-Waniewska, S. Investigations on the influence of acoustic and
ultracoustic field on biochemical process. .Acta Physiologica Polonica
Ellis, D. H., J. G. Goodwin, Jr., and J. R. Hunt. Wildlife and electric
power transmission, pp. 81-104. In. Fletcher, J. L. and R. G. Busnel (ads.).
Effects of doise on Wildlife. Academic Press, Inc., New York, 1978.
FAO Fisheries Report No. 76. Report, on a meeting for consultations en under-
water r.oise. Food and Agriculture Organization of the United Nations, April
1970.
Feist, J. 0., W. P. McCrory, and J. J. Russell. Distribution of Dall Sheep
in the Kount Goodenough area, Northwest Territories. Studies of Large Mammal
Populations in Northern Alaska, Yukon, and Northwest Territories. In McCourt,
K. H. and L. P. Horstman (eds.), Arctic Gas Biological Report Series, Vol. 22,
Ch. 2, 1973.
Fell, R. D., C. J. Ellis, and D. R. Griffith. Thyroid responses to acoustic
stimulation. Environmental Research 12:208-213; 1976.
Fine, M. L. Seasonal and geographical variatlan of the mating call of the
oyster loadvish Opsanus tau L. Oecologia 36:45-57, 1978.
Fine, M. L. Mismatch between sound production and hearing in tha oyster
toadfish. J_n_ Fay, R. R.,'A. N. Popper and W. N. Tavolga (eds.). Hearing and
Sound Communication in Fishes. Springer Yerlag, New York, 1981. In press.
Fine, M. L. and M. L. Lcnhardt. Pilot investigation of environmental and
biological effects on emission and propagation of the toadfish mating call.
Unpublished manuscript, Virginia Cotimonwealth University, 1980,
Fish, J. F. and J. S. Vanii. Killer whale, Orcinus orca, sounds repel white
whales, Oelphinapterus leucas. Fishery Bulletin, July 1971.
Fletcher, J. I.. Effects of noise on wildlife and other animals. NTIO 300.5.
U.S. Environmental Protection Agency, Washington, D.C. December 31, 1971.
Fletcher, J. L. Effects of noise on wildlife and other animals, review of
research sinct 1971. Reoort to Office of Noise Abatement and Control, U.S.
Environmental Protection Agency, Washington, D.C. (Unpublished paper)
Fletcher, J. L. and R. G. Busn|l (eds.). Effects of Noise on Wildlife.
Academic Press, Inc., New York, 1978.
-------
Fried-iiar-, M., S. 0. Byers,. and A. E. B«-cwn. Plasma lipid responsss of rats
and rabbits to an auditory stimulus. American Journal of Physiology
212:1174-1178, 1967-
Frings, H. and M. Frings. Reactions of swarms of Pentaneura aspera (Diptera:
Tendipedidae) to sound. Annals of the Entomological Society of America
52:728-733, 1959.
Frings, H. and F- Little. Reactions of honey bees in the hive to simple
sounds. Science 125:122, 1957.
Geber, W. F. Cardiovascular and teratogenic effects of chronic intermittent
noise stress. Jjrc Welch, B. L. and A. S. Welch (eds.)- Physiological effects
of noise. Plenum, New York, 1970.
Geber, W. F., T. A. Anderson, and B. Van Dyne. Physiologic response of the
albino rat to chronic noise stress. Archives of Environmental Kealth
12:751-754, 1966.
Gibson, J., H. Blend, and B. H. Brattstrom. (Departments of Physics- and
Biology, California State University, Fuller-ton, CA). Sound levels trans-
mitted into burrows of desert mammals, (unpunished paper)
Gollop, M. A. and R. A Davis. Gas compressor noise simulator disturbance
to snow geese, Komakuk Beach, Yukon Territory, September, 1972. In Gunn H.
W. *nd J. A. Livingston (eds.)- Disturbance to birds by gas compressor noise
simulators, aircraft, anu human activity in the Mackenzie Valley and on the
North Slope. 1972. Arctic Gas Biological Report Series 14, Chapter 2. Canadian
Arctic Gas Study Ltd., Calgary, 1S74.
Graham, F. Ear pollution, Audubon 71:34-39, 1969.
Greaves, J. H. and F. P. Rowe. Responses of confined rodent populations to
an ultrasound generator. Journal of Wildlife Management 33:409-417, 1969.
Griffin, 0. R.B J. J. G. McCue and A. 0. Grinnell. The resistance of bats
to jansning. Journal of Experimental Zoology 152:229-250, 1963.
Groh, L. S. The effects of two litter sizes and two levels of noise during
infancy upin the adult behavior of the white rats. Dissertation Ab^racts
27:598-599, 1965.
Hanson, J. 0., M. E. Larson, anJ C. T. Snov»don. The effects of control over
high intensity noise on plasma cortisol levels in Rhesus monkeys. Behavioral
Biology 16:333-340, 1976.
*
Harbers, L. H., D. R. Ames, A. B. Davis, and M. B. Akmed. Digestive responses
of sheep to auditory stimuli. Journal of Animal Science 41:654-658, 1^75.
Harrison, R. Quantifying acoustic close whsn determining effects of noise on
wildlife, pp. 267-285. I_n Fletcher, J. L. andR. G. Busnel (eds). Effects
of noise on wildlife. Academic Press, Inc., New York, 1978,
90
-------
Hattls, D. and 8. Richardson. Noise, general stress responses, and cardio-
vascular disease processes: review and reassessment of hypothesized rela-
tionships. Draft report prepared for the Environmental Protection Agency
Contract Ho. 68-01-4750, Feb. 1980.
Henderson, 0., R. P. Hamernlk, and K. Hynson. Hearing loss from simulated
work-week exposure to impulse noise. Journal of the Acoustical Society of
America 65(5):1231-1237, Hay 1979. *
Henkin, H. The death of birds. Environment 11:S1, 1969.
H111, E. P. Bat control with high frequency sound. Pest Control 38:18.
1970.
Hlroshige, T., T. Sato, R. Ohta and S. Itoh. Increase of corticotrcpin-
releaslng activity in the rat hypothalamus following noxious stimuli. The
Japanese Journal of Physiology 19:866-875, 1959.
Hol/ey, 0. N. (ed.). The Merck manual of diagnosis and therapy. 12th ed.
Merck Sharp S Dohse Research Laboratories, Rahway, H. J., 1972.
Hrubes, V. Changes 1n concentration of non-estarlfied fatty acids in the
rat plasma after load. Activitas Nervosa Superior 6:60-62, 1964.
Hrubes, V- and V= Benes. T'ne Influence of repeated noise stress en rats.
Acta Biologica et Medica Germanfca 15:592-596, 1S65.
Ishil, H. and K. Yokobori. Experimental studies on teratoganic activity
of noise stimulation. Gunma Journal of Medical Sciences 9:153-167, 1960.
Jacobson, J. 0. Potential Impact of the Mackenzie gas pipeline on bird popu-
lation in the Yukon and Northwest Territories Ch. 6 in Res. Reports. Vol.
IV. Environmental impact assessment of the portion of the Mackenzie gas
pipeline from Alaska to Alberta: Environmental Protection Board, Winnipeg,
1974.
Jakimchuk, R. D., E. A. OeBock, H. J. Russell and G. R. Setnechuk. A study
of the Porcupine Caribou herd. The Porcupine caribou herd—Canada. Ed. by
Jakimchuk, R. 0. Arctic Gas Biological Reports Series, Vo'i. IV. Canadian
Arctic Gas Study Ltd. and Alaska Gas Study Co., 1974.
Jeannoutot, D. W. and J. L. Adams. Progesterone versus treatment by high
intensity sound as methods of controlling broodiness in broad breasted bronze
turkeys. Poultry Science 40:512-521, 1961.
••
Jensen, M. M. and A. F. RasmusSen. Audlogenic stress and susceptibility to
Infection, pp. 7-17. In, Welch, B. L. and A. S. Welch (Eds.). Physiological
Effects of Noise, 1970.
& •
Jurtshuk, P., A. S. Weltman and A. M. Sackler. Biochemical response of rats
to auditory stress. Science 129:1424-1425, 1959.
91
-------
Kimmel, C. A., R. 0. Cook, and R. E. Staples. Teratogsnic potential of noise
In mice and rats. Toxicology and Applied Pharmacology 36:239-245, 1976.
•
Kirkpatrick. R. L. and P. K. Harein. Inhibition of reproduction of Indian-
Heal Hoths, Plo^jj. jnterpunctella, by exposure to amplified sound. Journal
of Economic Entosolo^~lO27P97l, 1965.
»,°* R' Reaction of reindeer to obstructions and disturbances. Science
:393-398, 1971.
Klein, D. R. The reaction of some northern mammals to aircraft disturbances.
ilth International Congress of Game Biologies. Stockholm, Sweden, 1973.
Knight, C. B. Basic Concepts of Ecology. The Macmillan Cotnpany, New York,
1965.
Konishi, M. Comparative neurophysirlogical studies of hearing and vocaliza-
tions in songbirds. Zeitichrift fuer Vergleichende Physiologic 67:363-381,
1967.
Kucera, E. Potential effects of the Canadian arctic gas pipeline en the
mammals of Western Arctic. Ch. 4 in Res. Reports, Vol. IV. Environmental
impact assessment of the portion of the MadCenzie gas pipeline from Alaska
to Alberta; Environmental Protection Board, Winnipeg, 1974.
Langowski, 0. J., H. M. Wight, and J. N. Jacobson. Responses of instrument-
ally conditioned starlings to aversive acoustic stimuli. Journal of Wildlife
Management 33:669-677, 1969.
Lee, J. H., Jr. ami 0. B. Griffith. Transmission line audible noise and
wildlife, pp. 105-168. In Fletcher, J. L. and R. G. Busael (eds.). Effects
of Noise on Wildl ifs. AcadV.i1c Press, Inc., Nea York, 1973.
Liberman, M. C. and D. G. Beil. Hair cell condition and auditory nerve
response in normal and noise-damaged cochleas. Acts Oto-Laryngologiea
88:161-176, 1979.
Lindgren, 0. L. Maintaining marketability of stored grain and cereal products.
Agriculture Department of Cooperative State Research Service, California, 1969.
Lindzey, G. Emotionality and audiogenic seizure susceptibility in five
inbred strains of srice. Journal of Comparative and Physiological Psychology
44:389-393, 1951.
Little, H. F- Reactions of honey bees to oscillations of known frequency.
Anatomical Record 134:601, 1959.
Luz, G. and J. B. Surith. Reaction of Pronghorn antelope to helicopter over-
flight. Journal of the Acoustical Society gf America 59:1514-1515, 1S76.
Lynch, T. E. and D. M. Speaks. Eastern wild turkey behavioral responses
induced by sonic boost, pp. 47-61. In Fletcher, J. L. and R. G. Busnel (eds.).
Effects of Noice on Wildlife. Academic Press, Inc., New York, 1978.
92
-------
Malar, T. and H. Kleerekoper. Observations on some effects of sound Inten-
?«;« 'ocomotor patterns of naive goldfish. American Zoologist 8:741-742,
196!) • • >
. P., M. Konlshl. A. Lutjln and H. S. Waser. Effects of continuous
noise on avlan hearing and development. Proceedings of the National Academy
of Sciences 70:1393-1396, 1973.
McCourt, K. H., J. J. Russell, D. Doll,*,). D'. Feist, and W. McCrory. Distri-
bution and movements of the Porcupine caribou herd 1n the Yukon, 1972. In R.
0. Jakimchuk (ed.). The Porcupine caribou herd - Canada. Arctic Gas Biologi-
cal Report Series Vol. 4. Canadian Arctic Gas Study Ltd., Calgary. 1974.
Hech, L. 0. The wolf: the ecology and behavior of an endangered species The
Natural History Press, Garden City, N.Y., 1970.
Messersjwith, D. H. Control of bird depredation. Agriculture Department
Cooperative State Research Service, Maryland, 1970.
Mc-tz, B., G. Brandenberger, and M. Follerilus. Endocrine responses to acoustic
stresses, pp 262-269. |n. Assenmacher, I. and D. S. Farner (eds.). Environ-
mental Endocrinology. Springer, Berlin, 1978.
Miline, R., V. Devecerski, and R. Krstic. Effects of auditory stimuli on the
pineal gland of the bat during hibernation. Acta Anatomica 73(36): 293-300,
1969.
Mills, J. H. Threshold shifts produced by 90-day exposures to noise. In
Henderson, D., R. P. Hamarnik, D. S. Oosanjh, and J. H. Mills (eds.)- ETfects
of Noise on HeTrTng. N.Y., Raven Press, 1976.
Moen, A. N. Energy conservation by white-tailed deer in the winter. Ecology
57:192-198, Winter 1976.
Holler, A. R. Noise as a health hazard. Amblo 4(1):6-13, 1975.
Moller, A. Review of animal experiments. Journal of Sound -and Vibration
59(1): 73-77, 1978.
Monaenkov, A. M. Influence of prolonged stimulation by sound of an electric
bell on conditioned-reflex activity in mammals. Zhurnal Vysshei Nervnol
Deiatel'nostilm I. P. Pavlova 6:891-397, 1956. Psychological Abstracts 32,
1958.
Monastyrskaya, B. I., I. B. Prak.h'e andR. A. Khaunina. Effect of acoustic
stimulation on the pituitary adrenal systun in healthy rats and rats gene-
tically sensitive to sound. Bulletin of Ex?erirr<;ntal Biology and Medici na
68:1357-1360, 1969. (English translation)
J.
Moody, D. B., W. C. Stebbins, and J. E. Hawkins, Jr. Noise-Induced hearing
loss In the monkey, pp. 309-325. In Henderson, D., R. P. Hamarnik, D. S.
Dosanjn, and J. H. Mills (eds.)« E??ects of Noise on Hearing. Raven Press,
New Ycrk, 1975.
93
-------
Moody, D. B.. W. C. Stebbins, J. E. Hawkltis, Jr. and L. G. Johnsson. Hearing
loss and cochlear pathology in the monkey (Macace) following exposure to high
levels of noise. Archives-of Otorhinolaryngolo^y 220(1-2): 47-72, March 3,
1973.
Myrberg. A. A. Jr. Ocean noise find the behavior of marine animals relation-
ships and Implications, pp. 461-491. In Dlessr, F. P., F. J. Vernberg, and
D. Z. Mirtes (©ds.) Advanced Concepts In Ocean Measurements for Marine Biology.
University of South Carolina Press, Columbia, 1980.
Nealls, P.M. and R. E. Bowman. Behavioral and corticosterold responses of
Rhesus monkeys to noise-induced stress. (Unpublished paper)
Ogle, C. U. and H. F. Lockett. The release of neurohypophysial hormone by
sound. Journal of Endocrinology 36:281-290, 1966.
Osintseva, V. P., H. H. Pushiclna, T. I. Bonashevskaya, and V. F. Kaverfna.
Noise induced changes in the adrenals. Hygiene and Sanitation 34:147-151,
1969.
Parker, J. B. and M. D. Bayley. Investigations on effects of aircraft sound
on oilk production of dairy cattle 1957-1958. United States Department of
Agriculture, Agriculture Research Service, Animal Husbandry Research Division,
22 p., 1%0.
Pearson, E. VL, P. R. Skon, and G. M. Corner. Dispersal $f urban roosts with
records of starling distress calls. Journal of Wildlife Management 31:502-506,
1967.
Peterson, E.A. No*s® and laboratory animals. In^Welty, E. C., Jr. (ed.).
Defining the laboratory animal and its environment: Setting the parameters.
Laboratory Animal Science 30(2):422-439, 1980.
Peterson, E. A. SOSBB issues and Investigations concerning extra auditory
effects of noise. Paper presentsd at the American Psychological Association
Symposium on the Non-Auditory Effects of Noise, New York, May 1979.
Peterson, E. A., J. S. Augenstein, R. S. Hosek, K. J. Klose, K. Manas, J.
Bloom, S. Lovett, and D. A. Greenberg. Noise and cardiovascular function in
Rhesus monkeys. Journal of Auditory Research 15:234-251, 1975.
Peterson, E. A., D. C. Tanis, J. S. Augenstein, R. A. Seifert, and H. R.
Bromley. Noise and cardiovascular function in Rhesus monkeys: II. ln_ ASH A.
Proceedings of the 3rd International Congress on Noise as a Public Health
Problem, Freiburg, West Germany., American Speech-Language-Hearing Associa-
tion, Rodcville. Maryland, 198CU
Ponomar'kov, V. I., Yu Tysik, V. 1. Kidryavtseva, A. S. Barer, V. K. Kostin,
V. Ye. Le?hchenko, R. M. Morozo^a, L. V. NospMn, and A. N. Frolov. NASA TT
F-5291, "Problems of Space Biology," Vol. 7, Operational Activity, Problems
or Habltability and Biotechnology NASA, May 1969.
94
-------
Popper, A. H. and R. R. Fay. Sounj detection and processing by teleost
CaVleW* J°Urna1
J°Urna1 of the Ac0ust1cal Society of America
Potash, L. M. A signal detection problem and possible solution in Japanese
quail. Animal Behavior. (In press)
Pye, J. 0. Ultrasonic bioacoustics, F^nal Scientific Report, llth May,
1965 - 30th June. 1970. U.S. Government Research and Reports Index 1971,
No. 1, p. SU-2, No. AD 7H 532.
Relrvis, S. Acute changes 1n animal inner ears due to simulated sonic booms.
Journal of the Acoustical Society of America 60(1):133-138, 1976.
Rennlson, 0. C. and A. K. Wallace. The extent of acoustic influence of off-
road vehicles in Australia. Proceedings of the National Symposium of Off-
Road Vehicles in Australia, Canberra, Feb. 1976, ISBN-0-9593775-4-1.
Roseneau, 0. G. and C. Warbelow. Distribution and numbers of musk oxen in
Northeastern Alaska and the Northern Yukon. Studies of Large Mamnal Popula-
tions in Northern Alaska. Yukon and Northwest Territories. Ed. oy McCourt,
K. H. and L. P. Korstman. Arctic Gas Biological Report Series, 1973.
Rucker, R. R. Effect of sonic boom on fish. Final Report. Department of
Transportation. FAA Systems Research and Development Service, Washington, D.
C., 1973.
Saunders, J. C. and G. R. Bock. Influences of early auditory trauma on audi-
tory development, pp. 249-287 J_n Gottlieb, G. (ed. ). Studies on the Devel-
opment of Behavior and the Nervous System Vol. 4: Early Influences. Academic
Press, New York, 1978.
Selye, H. A syndrome produced by diverse nocuous agents. Noture 138:32,
1936.
Selye, H. Forty years of stress research: principal remaining problems and
misconceptions." Canadian Medical Association Journal 115(l}:52-6, 1976.
Sewell, G. D. Ultrasonic signals from rodents. Ultrasonics 8:26-30, 1970.
Shaw, E. A. G. Symposium on the effects cf noise on wildlife, pp. 1-5.
^Fletcher, J. L. andR. G. Busnel (eds.) Effects of Noise on Wildlife.
Academic Press, New York, 1978.
Shaw, E. W. California Condor. Library of Congress Legislative Reference
Service, SK351, 70-127, 1970. '.'
Shulov, A. S. Acoustic responses of locusts— Sen istocera, Dodostarus. and
Aerpt£lus_. U.S. D-pt. of Agriculture, Agricultural Research Service, Entomol-
ogy"Research Division, 1969.
95
-------
P' Ra°* • Stud1es on th® Polycystic ovaries of rats under
" Amer1C£n Journal of Obstetrics and Gynecology,
SOOT. R. J. 6. Sollinger, and 0. J. Rongstad. Studying the effects of
snowmobile noise on wildlife. Proceedings of IntemoUa 72. Washington,
D.C. October 4-6. pp. 236-241, 1972.
Sprock, C. M., H. E. Howard, and F. C. Jacob, ^ound as a deterrent to rats
and mice. Journal of Wildlife Management 31:729-741, 1967.
Stadelroan, H. J. The effect of sounds of varying intensity on hatchability
of chicken egg. Poultry Science 37:i66-169, 1958a.
Stadelman, M. J. Observations with growing chickens on the effects of sounds
of varying intensities. Poultry Science 37:776-779, 1958b.
Thompson, R. 0., C. V. Grant, E. H. Pearson, and G. W. Comer. Cardiac response
of starlings to sound: effects of lighting and grouping. American Journal of
Physiology 214:41-44, 1968a. ,
Tho»ipsonB R. 0., C. V. Grant, E. V,. Pearson, and G. W. Corner. Differential
heart rate response of startlings to sound stirmili of biological origin. The
Journal of Wildlife Management 32: 888-893, 1968b.
Thompson, y. 0. and L. W. Sontag. Behavioral effects in the offspring of rats
subjected to audiogenic seizures during the gestational period. Journal of
Cc33parative and Physiological Psychology 49:454-455, 1956.
Thorpe, W. H. The significance of vocal imitation in animals with special
reference to birds. Acts Biologica Experlmentia 29:251-269, 1969.
Travis, H. F., G. V- Richardson, J. R. Menear, and J. Bond. The effects of
s1 related sonic booais on reproduction and behavior of farm-raised mlntc. ARS
44-200, U.S. Deparfcnent of Agriculture, Agricultural Research Service, 1968.
Travis, H. F., J. Bond, R. L. Wilson, J. R. Leekley, and J. R. Mencar.
Effects of sonic booss on reproduction of mink. Journa^ of Animal Science
35:195, 1972.
Treptow, K. Dynamics of glycenric reactions after repeated exposure to noise.
Activitas Kervosa Superior 8:215-216, 19S6.
, C. Perception and behavioral effects of sound in the Indian-Meal Moth.
U.S. Department of Agriculture,. Agriculture Research Service, Market Quality
Research Division, 19S9.
United States Department of the Interior. Environmental impact of the Big
Cypress Swamp Jetport, 155 p. ,j,1969.
Vender, A. J., J. H. Sherman, and 0. S. Luciano, Human Physiology, the
Mechanises cf Body Function. 2nd ed. McGraw-Hill, New York, 1975.
96
-------
Vandsr, A. a., u L. Kay, K. E. Dugan, and 0. R, Mouw. Effects of noise on
Plasma renln activity 1n rats. Proceedings of the- Socl&ty for Experimental
Biology and Medicine. 156< 24, 1S77.
Vince, M. A. Artificial acceleration of hatching in quail embryos, Aniral
Behavior 14:389-394. 1966.
Wards C. 0., M. A. Barletta and T. Kays. Teratogenic effects of sudiogenlc
stress In albino rales. Journal of Pharmaceutical Sciences 59:1661-1052,
1970.
Welch', 8. L. Env1rofi(?®ntal Noise, "adaptation" and pathological change, pp
5-6 in Welch, B. L. and A. S. Welch (eds.). Physiological Effects of
Noise. Plenum Press, Ken York, 1970.
Werner, R. Influence of sound on the intermediary lobe of the rat hypophysis.
Compte Rendus Oe 1 'Association des Anatonristes 45:78-788, 1959,
Wight, H. M. Development and testing of methods for repelling starlings that
roost 1n holly. Oregon State Government, 1971.
Yeakel, E. H., H. A. Shenkin, A. B. Rothballer and S. M. McCann. Adrenal ectoray
and blood pressure of rats subjected to auditory ?*.i relation. Journal of
Physiology 155:118-127, 1943.
Zondek, 8. Effect of auditory stimuli on female reproductive organs. New
England Obstetrical and Gynecological Society 18:177-185, 1964.
Zondek, B. and T. Isschar. Effect of audiogenic stimulation on genital func-
tion and reproduction. Acta EndocrinoKogica 45:227-234, 1964.
Zoric, V. Effects of sound on mouse testes. Acta Anatomica 38:176. 1959
Anon. Flarringos find they're off the track' Conservation Mews 5:12. May 15,
1C78.
97
------- |