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Noise:
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Noise:
A Health
Problem
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"Health is a state of complete
physical, mental and social well-
being. Governments have a responsi-
bility for the health of their people
which can be fulfilled only by the pro-
vision of adequate health and social
measures."
World Health Organization
Introduction
Racket, din, clamor, noise.
Whatever you want to call it, un-
wanted sound is America's most
widespread nuisance. But noise is
more than just a nuisance. It con-
stitutes a real and present dan-
ger to people's health. Day and
night, at home, at work, and at
play, noise can produce serious
physical and psychological
stress. No one is immune to this
stress. Though we seem to ad-
just to noise by ignoring it, the
ear, in fact, never closes and the
body still responds sometimes
with extreme tension, as to a
strange sound in the night.
The annoyance we feel when
faced with noise is the most com-
mon outward symptom of the
stress building up inside us. In-
deed, because irritability is so ap-
parent, legislators have made
public annoyance the basis of
many noise abatement programs.
The more subtle and more serious
health hazards associated with
stress caused by noise tradi-
tionally have been given much
less attention. Nonetheless, when
we are annoyed or made irritable
by noise, we should consider
these symptoms fair warning that
other things may be happening to
us, some of which may be
damaging to our health.
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Of the many health hazards re-
lated to noise, hearing loss is the
most clearly observable and
measurable by health profes-
sionals. The other hazards are
harder to pin down. For many of
us, there may be a risk that ex-
posure to the stress of noise in-
creases susceptibility to disease
and infection. The more suscept-
ible among us may experience
noise as a complicating factor in
heart problems and other dis-
eases. Noise that causes annoy-
ance and irritability in healthy per-
sons may have serious conse-
quences for those already ill in
mind or body.
Noise affects us throughout our
lives. For example, there are indi-
cations of effects on the unborn
child when mothers are exposed
to industrial and environmental
noise. During infancy and child-
hood, youngsters exposed to high
noise levels may experience learn-
ing difficulties and generally suf-
fer poorer health. Later in life, the
elderly may have trouble falling
asleep and obtaining necessary
amounts of rest.
Why, then, is there not greater
alarm about these dangers? Per-
haps it is because the link be-
tween noise and many disabilities
or diseases has not yet been
conclusively demonstrated. Per-
haps it is because we tend to dis-
miss annoyance as a price to pay
for living in the modern world. It
may also be because we still think
of hearing loss as only an occupa-
tional hazard.
The effects of noise on health
are often misunderstood or un-
recognized. Well-documented
studies to clarify the role of noise
as a public health hazard are still
required, but we at least know
from existing evidence that the
danger is real. In the following
nine sections, this booklet de-
scribes the ways that noise en-
dangers our health and well-being:
Hearing Loss
Heart Disease
The Body's Other Reactions
Noise and the Unborn
Special Effects on Children
Intrusion at Home and Work
Sleep Disruption
Mental and Social Well-Being
Danger to Life and Limb
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"Deafness, like poverty, stunts and
deadens its victims." Helen Keller
Hearing Loss
Noise loud enough to cause
hearing loss is virtually every-
where today. Our jobs, our enter-
tainment and recreation, and our
neighborhoods and homes are
filled with potentially harmful ""
levels of noise. It is no wonder
then that 20 million or more Amer-
icans are estimated to be ex-
posed daily to noise that is per-
manently damaging to their
hearing.
When hearing loss occurs, it is
in most cases gradual, becoming
worse with time. The first aware-
ness of the damage usually be-
gins with the loss of occasional
words in general conversation
and with difficulty understanding
speech heard on the telephone.
Unfortunately, this recognition
comes too late to recover what is
lost. By then, the ability to hear
the high frequency sounds of, for
example, a flute or piccolo or even
the soft rustling of leaves will
have been permanently dimin-
ished. As hearing damage con-
tinues, it can become quite sig-
nificant and handicapping. And
there is no cure. Hearing aids do
not restore noise-damaged hear-
ing, although they can be of lim-
ited help to some people.
People with partial deafness
from exposure to noise do not
necessarily live in a quieter world.
The many sounds still audible to
them are distorted in loudness,
pitch, apparent location, or clar-
ity. Consonants of speech, es-
pecially high frequency sounds
such as "s" and "ch," are often
lost or indistinguishable from
other sounds. Speech frequently
seems garbled, sounding as if
the speaker has his or her "head
in a barrel." When exposed to a
very loud noise, people with par-
tial hearing loss may experience
discomfort and pain. They also
frequently suffer from tinnitus
irritating ringing or roaring in the
head.
There is even further pain the
hard-of-hearing person faces: the
emotional anguish caused, per-
haps unintentionally, by friends
and associates who become less
willing to be partners in conversa-
tion or companions in other activi-
ties. Indeed, the inability to con-
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verse normally makes it difficult
for partially deaf people to partici-
pate in lectures, meetings, par-
ties, and other public gatherings.
For a person with hearing loss,
listening to TV, radio, and the tele-
phone important activities of
our lives is difficult, if not
impossible.
As hearing diminishes, a severe
sense of isolation can set in. The
greater the hearing loss, the
stronger the sense of being cut
off from the rest of the world.
What eventually may be lost is
the ability to hear enough of the
incidental sounds that maintain
our feeling of being part of a liv-
ing world. The emotional depres-
sion following such hearing loss
is much the same, whether the
impairment has been sudden or
gradual.
The idea that hearing
loss is solely the result of in-
dustrial noise is dangerously er-
roneous. Noise levels in many
places and in some of the trans-
portation vehicles we use are well
above the levels believed to cause
hearing damage over prolonged
periods. As a rule, whenever we
need to raise our voices to be
heard, the background noise may
betooloudandshouldbeavoided.
Noise can cause permanent
hearing damage
People with hearing loss suffer dis-
comfort and social isolation
Hearing loss is not solely an occu-
pational hazard
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"We now have millions with heart
disease, high blood pressure, and
emotional illness who need protec-
tion from the additional stress of
noise." Dr. Samuel Rosen,
Mt. Sinai Hospital
Heart Disease
While no one has yet shown that
noise inflicts any measurable
damage to the heart itself, a grow-
ing body of evidence strongly sug-
gests a link between exposure to
noise and the development and
aggravation of a number of heart
disease problems. The explana-
tion? Noise causes stress and the
body reacts with increased adren-
aline, changes in heart rate, and
elevated blood pressure.
Noise, however, is only one of
several environmental causes of
stress. For this reason, research-
ers cannot say with confidence
that noise alone caused the heart
and circulatory problems they
have observed. What they can
point to is a statistical relation-
ship apparent in several field and
laboratory studies.
The best available studies are
those that have been conducted
in industrial settings. For ex-
ample, steel workers and machine
shop operators laboring under the
stress of high noise levels had a
higher incidence of circulatory
problems than did workers in
quiet industries. A German study
has documented a higher rate of
heart disease in noisy industries.
In Sweden, several researchers
have noted more cases of high
blood pressure among workers
exposed to high levels of noise.
Some laboratory tests have pro-
duced observable physical
changes. In one instance, rabbits
exposed for 10 weeks to noise
levels common to very noisy in-
dustries developed a much
higher level of blood cholesterol
than did unexposed rabbits on
the same diet.
Similarly, a monkey subjected
to a day-long tape recording of the
normal street noises outside a
hospital developed higher blood
pressure and an increased heart
rate. In a test on humans, people
subjected to moderately loud
noise during different states of
sleep exhibited constriction of the
outer blood vessels.
Among the more serious re-
cent findings in settings other
than the laboratory or industry is
the preliminary conclusion that
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grade school children exposed to
aircraft noise in school and at
home had higher blood pressures
than children in quieter areas. The
exact implications for these chil-
dren's health are not known, but
certainly this finding is cause for
serious concern.
Because the danger of stress
from noise is greater for those al-
ready suffering from heart dis-
ease, physicians frequently take
measures to reduce the noise ex-
posure of their patients. For in-
stance, a town in New Jersey
moved a firehouse siren away
from the home of a boy with con-
genital heart disease when his
doctor warned that the sound of
the siren could cause the boy to
have a fatal spasm. Another doc-
tor ordered a silencing device for
the phone of a recuperating heart
patient.
As William Stewart, former Sur-
geon General of the United States,
has pointed out, there are many
incidents of heart disease occur-
ing daily in the U.S. for which "the
noise of twentieth century living
is a major contributory cause."
While the precise role of noise in
causing or aggravating heart dis-
ease remains unclear, the illness
is such a problem in our society
that even a small increase in the
percentage of heart problems
caused by noise could prove
debilitating to many thousands of
Americans.
Noise may produce high blood
pressure, faster heart rates, and in-
creased adrenaline
Noise may contribute to heart and
circulatory disease
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"Loud noises once in a while prob-
ably cause no harm. But chronic
noise situations must be patholog-
ical. Constant exposure to noise
is negative to your health."
Dr. GerdJansen, Ruhr University
The Body's
Other
Reactions
In readiness for dangerous and
harmful situations, our bodies
make automatic and unconscious
responses to sudden or loud
sounds. Of course, most noise in
our modern society does not sig-
nify such danger. However, our
bodies still react as if these
sounds were always a threat or
warning.
In effect, the body shifts gears.
Blood pressure rises, heart rate
and breathing speed up, muscles
tense, hormones are released into
the bloodstream, and perspiration
appears. These changes occur
even during sleep.
The idea that people get used
to noise is a myth. Even when we
think we have become accus-
tomed to noise, biological
changes still take place inside us,
preparing us for physical activity
if necessary.
Noise does not have to be loud
to bring on these responses.
Noise below the levels usually as-
sociated with hearing damage
can cause regular and predictable
changes in the body.
What happens to the human
body when confronted with ever-
present noise? In a world where
steady bombardment of noise is
the rule rather than the exception,
the cumulative effects of noise on
our bodies may be quite exten-
sive. It may be that our bodies are
kept in a near-constant condition
of agitation. Researchers debate
whether the body's automatic re-
sponses build on each other, lead-
ing to what are called the "dis-
eases of adaptation." These dis-
eases of stress include ulcers,
asthma, high blood pressure,
headaches, and colitis.
In studies dating back to the
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1930s, researchers noted that
workers chronically exposed to
noise developed marked digestive
changes which were thought to
lead to ulcers. Cases of ulcers in
certain noisy industries have been
found to be up to five times as
numerous as what normally would
be expected.
Similar research has identified
more clearly the contribution of
noise to other physical disorders.
A five-year study of two manufac-
turing firms in the United States
found that workers in noisy plant
areas showed greater numbers of
diagnosed medical problems, in-
cluding respiratory ailments, than
did workers in quieter areas of the
plants.
From a study done with
animals, researchers concluded
that noise may be a risk factor in
lowering people's resistance to
disease and infection.
To prevent aggravation of
existing disease, doctors and
health researchers agree that
there is an absolute requirement
for rest and relaxation at regular
intervals to maintain adequate
mental and physical health. Con-
stant exposure to stress from
noise frustrates this requirement.
In doing so, it has a potentially
harmful effect on our health and
well-being.
Noise can cause regular and pre-
dictable stress in the human body
People do not get used to noise
the body continues to react
Noise may aggravate existing
disease
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"There is ample evidence that en-
vironment has a role in shaping the
physique, behavior and function of
animals, including man, from con-
ception and not merely from birth.
The fetus is capable of perceiving
sounds and responding to them by
motor activity and cardiac rate
change."
Lester W. Sontag, The Pels
Research Institute
Noise and the
Unborn
While still in its mother's womb,
the developing child is responsive
to sounds in the mother's en-
vironment. Particularly loud
noises have been shown to
stimulate the fetus directly,
causing changes in heartrate.
Related work also has demon-
strated that, late in pregnancy,
the fetus can respond to noise
with bodily movements such as
kicking.
Just as the fetus is not com-
pletely protected from environ-
mental noise, the fetus is
not fully protected from its
mother's response to stress,
whether it be caused by noise or
other factors. When her body
reacts to noise, the physical
changes she experiences may be
transmitted to the fetus. And it is
known that the fetus is capable of
responding to some changes in
the mother's body of the type
produced by emotion, noise, or
other forms of stress.
In contrast to the more direct
risk, this indirect fetal response
may threaten fetal development if
it occurs early in pregnancy. The
most important period is about 14
to 60 days after conception.
During this time, important
developments in the central ner-
vous system and vital organs are
taking place. Unfortunately,
women are often unaware that
they are pregnant for much of this
period, and are thus unlikely to
take extra precautions.
While very little research has
addressed these questions, due
to the difficulties of studying
humans in this respect, certain
suggestive human research has
been done.
A Japanese study of over 1,000
births produced evidence of a
high proportion of low-weight
babies in noisy areas. These birth
weights were under 51/2 pounds,
the World Health Organization's
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def initionof prematurity. Low birth
weights and noise were also
associated with lower levels of
certain hormones thought to af-
fect fetal growth and to be a good
indicator of protein production.
The difference between the
hormone levels of pregnant
mothers in noisy versus quiet
areas increased as birth ap-
proached.
Studies have also shown that
stress causes constriction of the
uterine blood vessels which sup-
ply nutrients and oxygen to the
developing baby. Additional links
between noise and birth defects
have been noted in a recent
preliminary study on people living
near a major airport. The abnor-
malities suggested included
harelips, cleft palates, and de-
fects in the spine.
Taken together, this infor-
mation points to the possibility of
serious effects of noise on the
growth and development of the
unborn child. While it cannot be
said at what level maternal ex-
posures to industrial and en-
vironmental noise are dangerous
to the fetus, these findings do
create some concern. It is known
that extreme stress of any type
will certainly take a toll on the
fetus, but, in the case of noise, it
is not known how much is
required to have an effect.
Whatever the effect, the risk of
even a slight increase in birth
defects is considerably
disturbing.
The fetus is not fully protected
from noise
Noise may threaten fetal develop-
ment
Noise has been linked to low birth
weights
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"Levels of noise which do not inter-
fere with the perception of speech by
adults may interfere significantly
with the perception of speech by
children as well as with the
acquisition of speech, language, and
language-related skills." National
Academy of Sciences Report
Special Effects
on Children
Good health includes the ability
to function mentally as well as
physically. This is especially true
during growth and development.
Adults have worried about the
effects of noise on children ever
since the early 1900s when "quiet
zones" were established around
many of the nation's schools.
These protective areas were in-
tended to increase educational
efficiency by reducing the various
levels of noise that were believed
to interfere with children's learn-
ing and even hamper their think-
ing ability.
Today's worries are little
changed from those of the past.
Researchers looking into the con-
sequences of bringing up children
in this less-than-quiet world have
discovered that learning dif-
ficulties are likely byproducts of
the noisy schools, play areas, and
homes i.n which our children grow
up. Two primary concerns are
with language development and
reading ability.
Because they are just learning,
children have more difficulty un-
derstanding language in the
presence of noise than adults do.
As a result, if children learn to
speak and listen in a noisy en-
vironment, they may have great
difficulty in developing such
essential skills as distinguishing
the sounds of speech. For exam-
ple, against a background of
noise, a child may confuse the
sound of "v" in "very" with the
"b" in "berry" and may not learn
to tell them apart. Another symp-
tom of this problem is the ten-
dency to distort speech by drop-
ping parts of words, especially
their endings.
Reading ability also may be
seriously impaired by noise. A
study of reading scores of 54
youngsters, grades two through
five, indicated that the noise
levels in their four adjacent apart-
ment buildings were detrimental
to the children's reading
development. The influence of
noise in the home was found to
be more important than even the
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parents' educational background,
the number of children in the
family, and the grades the
youngsters were in. The longer
the children had lived in the noisy
environment, the more pro-
nounced the reading impairment.
Assuming a child arrives at
school with language skills under-
developed because of a noisy
home, will he or she fare any
better at school? Again, the an-
swer may depend on how noisy
the classroom is. In a school
located next to an elevated
railway, students whose
classrooms faced the track did
significantly worse on reading
tests than did similar students
whose classrooms were farther
away. In Inglewood, California,
the effects of aircraft noise on
learning were so severe that
several new and quieter schools
had to be built. As a school of-
ficial explained, the disruption of
learning went beyond the time
wasted waiting for noisy aircraft
to pass over. Considerable time
had to be spent after each flyover
re-focusing students' attention on
what was being done before the
interruption.
But the problem may be well
beyond the capacity of the
schools to correct. Children who
live in noisy homes and play in
noisy areas may never develop
the ability to listen well enough to
learn once they are of school age.
To avoid this prospect, our con-
cern for the health and welfare of
the nation's children must be
broadened to address the total
environment in which they grow
up.
Noise may hinder the development
of language skills in children
Noise disrupts the educational
process
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"Interference with speech com-
munication by noise is among the
most significant adverse effects of
noise on people. Free and easy
speech communication is probably
essential for full development of in-
dividuals and social relations, and
freedom of speech is but an empty
phrase if one cannot be heard or un-
derstood because of noise." EPA
Report
Intrusion At
Home and
Work
DD
no
If there is one common
denominator degrading the
quality of all our lives, it may well
be the almost constant intrusion
of noise in the home, at work,
and in public areas. One of the
most bothersome aspects of this
intrusion is its interference with
conversation. We may not always
be aware of it, but we frequently
must speak up to be heard. Others
must often do the same to be un-
derstood by us.
Loss of the ability to speak at a
normal level and be heard may be
far more damaging than we
realize. People who live in noisy
places tend to adopt a lifestyle
devoid of communication and
social interaction. They stop
talking, they change the content
of the conversation, they talk only
when absolutely necessary, and
they frequently must repeat
themselves. These reactions are
probably familiarto all of us.
Interference with indoor con-
versation represents only a small
part of the intrusion problem.
Outdoors, the combination of
continuous daytime noise caused
by street traffic, construction
equipment, and aircraft interrupts
speech and can discourage con-
versation there as well. For
millions of Americans residing in
noisy urban areas, the use of out-
door areas for relaxed conver-
sation is virtually impossible.
Noise not only makes conver-
sation difficult indoors or out
it also seems to hinder work ef-
ficiency. In general, noise is more
likely to reduce the accuracy of
work rather than the total quan-
tity. And it takes a greater toll on
complex compared to simpler
tasks. When noise is particularly
loud or unpredictable, errors in
people's observation tend to in-
crease, perception of time may be
distorted, and greater effort is
required to remain alert. Loud
noise also can increase the
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variability of work, leading to
breaks in concentration
sometimes followed by changes
in work rate.
Even when noise does not inter-
fere with the work at hand, work
quality may suffer after the noise
stops. Studies and reports from
individuals also suggest that
people who work in the midst of
high noise levels during the day
are more, rather than less,
susceptible to frustration and
aggravation after work. Relaxing
at home after a noisy workday
may not be an easy thing to do.
When the home is noisy itself, the
tired and irritated worker may
never be able to work out the
day's accumulated stress during
the course of the evening.
Noise in industrial settings may
have the most pronounced effects
on human performance and em-
ployee health. A coal industry
study indicated that intermittent
noise conditions during mining
have a great likelihood for
causing distraction leading to
poorer work. Other studies have
confirmed additional effects of
noise exposure, including
exhaustion, absentmindedness,
mental strain, and absenteeism
all of which affect worker ef-
ficiency. In the words of Leonard
Woodcock, former president of
the United Auto Workers, "They
(auto workers) find themselves
unusually fatigued at the end of
the day compared to their fellow
workers who are not exposed to
much noise. They complain of
headaches and inability to sleep
and they suffer from anxiety . . .
Our members tell us that the con-
tinuous exposure to high levels of
noise makes them tense, irritable,
and upset."
Noise interferes with conversation
and social interaction
Noise hampers work efficiency
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"The din of the modern city [includes]
noises far above levels for optimum
sleeping. Result: insomnia and in-
stability."
Dr. Edward F. Crippen, Former
Deputy Health Commissioner of
Detroit
Sleep
Disruption
Sleep is a restorative time of
life, and a good night's sleep is
probably crucial to good health.
But everyday experience
suggests that noise interferes
with our sleep in a number of
ways. Noise can make it difficult
to fall asleep, it can wake us, and
it can cause shifts from deeper to
lighter sleep stages. If the noise
interference with sleep becomes
a chronic problem, it may take its
toll on health.
Human response to noise
before and during sleep varies
widely among age groups. The
elderly and the sick are par-
ticularly sensitive to disruptive
noise. Compared to young people,
the elderly are more easily
awakened by noise and, once
awake, have more difficulty retur-
ning to sleep. As a group, the
elderly require special protection
from the noises that interfere with
their sleep.
Other age groups seem to be
less affected by noise at bedtime
and while asleep. But their ap-
parent adjustment may simply be
the result of failing to remember
having awakened during the
night. Sleep researchers have
observed that their subjects often
forget and underestimate the
number of times they awaken
during sleep. It may be that loud
noises during the night continue
to wake or rouse us when we
sleep, but that as we become
familiar with the sounds, we
return to sleep more rapidly.
Factors other than age can in-
fluence our sleep. Studies
suggest that the more frequent
noise is, the less likely a sleeper
is to respond. Certain kinds of
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noises can cause almost certain
responses, however. A mother
may wake immediately at the
sound of a crying baby, but may
tune out much louder traffic noise
outside.
Disruption of sleep does not
necessarily include awakening.
Shifting in depths of sleep may be
more frequent than awakening.
For instance, recent studies have
shown that shifts from deep to
light sleep were more numerous
because of noise, and that light
sleep became lengthened at the
expense of deep sleep.
Studies have also been made of
noise complaints and what kinds
of annoyance led people to file
them. Surveys taken in com-
munities significantly affected by
noise indicated that the interrup-
tion of rest, relaxation, and sleep
was the underlying cause of
many people's complaints.
When noise interferes with our
sleep whether by waking us or
changing the depth of sleep it
makes demands on our bodies to
adapt. The implications of these
demands for our general health
and performance are not well un-
derstood. Nonetheless, we need
restful sleep and many of us are
not getting it. As a result, for
millions of Americans, trying to
get a good night's sleep still
means reaching for sleeping pills.
Noise affects the quantity
and quality of sleep
The elderly and sick are more sen-
sitive to disruptive noise
When sleep is disturbed by noise,
work efficiency and health may
suffer
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"The Noise, The Noise. I just couldn't
stand the Noise."
Suicide note left by a desperate
homeowner.
Mental and
Social
Weil-Being
The most obvious price we pay
for living in an overly noisy world
is the annoyance we frequently
experience. Perhaps because an-
noyance is so commonplace, we
tend to take our daily doses of it
for granted not realizing that
the irritability that sometimes sur-
faces can be a symptom of poten-
tially more serious distress inside
us. When noise becomes suffi-
ciently loud or unpredictable, or if
the stress imposed is great
enough, our initial annoyance can
become transformed into moreex-
treme emotional responses and
behavior. When this happens, our
tempers flare and we may "fly off
the handle" at the slightest
provocation.
Newspaper files and police
records contain reports of in-
cidents that point to noise as a
trigger of extreme behavior. For
instance, a night clerical worker,
upset about noise outside his
apartment, shot one of the boys
causing the disturbance after he
had shouted at them, to no avail,
to "Stop the noise." As other
examples, sanitation workers
have been assaulted, construc-
tion foremen threatened, and
motorboat operators shot at
all because of the noise they
were producing.
Such extreme actions are not
the usual responses to noise and
stress. Some people cope with
loud noise by directing their anger
and frustration inward, by blam-
ing themselves for being upset,
and by suffering in silence. Others
resort to a denial of the problem
altogether, considering them-
selves so tough that noise does
not bother them. Still others deal
with noise in a more direct man-
ner: they take sleeping pills and
wear ear plugs, increase their
visits to doctors and keep their
windows closed, rearrange their
sleeping quarters and spend less
time outdoors, and write letters of
complaint to government of-
ficials.
Most of the time these ways
of contending with noise are not
likely to eliminate the noise or
any underlying annoyance. Short
of taking extreme action which
is unlikely to solve the problem
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either most people who cannot
cope with noise in these ways
typically direct their anger and
frustration at others and become
more argumentative and moody,
though not necessarily violent.
This noise-induced, anti-social
behavior may be far more
prevalent than we realize.
Indeed, noise can strain
relations between individuals,
cause people to be less tolerant
of frustration and ambiguity, and
make people less willing to help
others. One recent study, for
example, found that, while a
lawnmower was running nearby,
people were less willing to help a
person with a broken arm pick up
a dropped armload of books.
Another study of two groups of
people playing a game found that
the subjects playing under noisier
conditions perceived their fellow
players as more disagreeable,
disorganized, and threatening.
Several industrial studies indicate
that noise can heighten social
conflicts both at work and at
home. And reports from in-
dividuals suggest that noise in-
creases tensions between
workers and their supervisors,
resulting in additional grievances
against the employer.
Although no one would say that
noise by itself brings on mental
illness, there is evidence that
noise-related stress can aggravate
already existing emotional disor-
ders. Research in the United
States and England points to
higher rates of admission to
psychiatric hospitals among
people living close to airports.
And studies of several industries
show that prolonged noise ex-
posure may lead to a larger
number of psychological
problems among workers.
Noise can cause extreme emo-
tions and behavior
Anti-social behavior caused by
noise may be more prevalent than
is realized
19
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"Inability to hear auditory warning
signals or shouts of caution because
of noise has also been implicated in
industrial accidents. "Alexander
Cohen, National Institute for Occupa-
tional Safety and Health
Danger to
Life and Limb
Two people were killed when
Senator Robert Kennedy's funeral
train passed through Elizabeth,
New Jersey. Because of the noise
from Secret Service and news
media helicopters, they did not
hear the warning blasts from the
train that hit them.
Although the evidence is scan-
ty, the inability to hear warning
signals because of high
background noise is thought to be
the cause of many accidents each
year. For example, traffic ac-
cidents occur and lives are lost
because drivers are unable to
hear the sirens from nearby or
passing emergency vehicles.
One study has estimated that
when a fire truck or ambulance is
in the process of passing a truck,
the truck driver is able to detect
the siren for only a very short time
three seconds or less. The rest
of the time the truck's noise
drowns out the siren, and the
warning is undetected.
Nowhere is the concern over
preventable accidents greater
than in industrial settings, where
noise levels not only can interfere
with concentration and can cause
hearing loss, but can hinder
communication between em-
ployees as well particularly in
times of emergency. A study of
medical and accident records of
workers in several industries
found that a significantly higher
number of reported accidents oc-
curred in noisier plant areas.
The Federal Railroad Administra-
tion is aware of this hazard and
has identified "high noise-level
conditions" as a possible contri-
butor in 19 accidents causing
deaths of 25 railroad employees,
in a 22-month period.
Reports from industrial of-
ficials also indicate that the ef-
fectiveness of warning signals
and shouts in noisy areas is con-
siderably diminished and that ac-
cidents and injuries are more fre-
20
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quent. The effects of masking
and speech interference can be
dramatic, as in the case of an ac-
cident in an auto glass manufac-
turing plant. Noise levels were so
high that a worker whose hand
was caught in manufacturing
equipment received no aid since
no one heard the screams. As a
result, the hand was lost. As ad-
ditional examples, two press-
room auto workers in Ohio were
permanently disabled when they
failed to hear approaching panel
racks or warning shouts.
Thus it is an unfortunate result
of high background noise levels
that people cannot respond in
life and death situations when
they are unable to hear ap-
proaching hazards or shouts of
alarm.
Noise can obscure warning sig-
nals, causing accidents to occur
Noise can interfere with shouts for
help, preventing rescue attempts
21
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"It is truly a serious problem to
escape from noise."
William Dean Howells, American
Author
A Final Word
22
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When unwanted sounds intrude
into our environment, noise
exists. We have all experienced to
varying degrees the annoyance
and irritation caused by noise.
Sometimes this annoyance is
brought about by disruption of our
sleep ordifficulty in falling
asleep. At other times, it may be
because we have to raise our
voices over background noise to
be heard or because we are
distracted from our activities.
Except for the serious problem
of hearing loss, there is no human
illness known to be directly
caused by noise. But throughout
dozens of studies, noise has been
clearly identified as an important
cause of physical and psycho-
logical stress, and stress has
been directly linked with many
of our most common health prob-
lems. Thus, noise can be asso-
ciated with many of these disabil-
ities and diseases, which include
heart disease, high blood pres-
sure, headaches, fatigue and
irritability.
Noise is also suspected to in-
terfere with children's learning
and with normal development
of the unborn child. Noise
is reported to have triggered
extremely hostile behavior
among persons presumably
suffering from emotional
illness. It is suspected
to lower our resistance, in some
cases, to the onset of infection
and disease.
However, most Americans are
largely unaware that noise poses
such significant dangers to their
health and welfare. The reasons
for this lack of awareness are
clear. Noise is one of many en-
vironmental causes of stress and
cannot easily be identified as the
source of a particular physical or
mental ailment by the layman.
Another reason is that biomedical
and behavioral research is only
now at the point where health
hazards stemming from noise can
actually be named, even though
some specific links have yet to be
found.
Dr. William H. Stewart, former
Surgeon General, in his keynote
address to the 1969 Conference on
Noise as a Public Health Hazard,
made the following point: "Must
we wait until we prove every link
in the chain of causation? I stand
firmly with (Surgeon General)
Burney's statement of 10 years
ago. In protecting health, ab-
solute proof comes late. To wait
for it is to invite disaster or to
prolong suffering unnecessarily.
I submit that those things within
man's power to control which im-
pact upon the individual in a
negative way, which infringe upon
his sense of integrity, and in-
terrupt his pursuit of fulfillment,
are hazards to public health."
It is finally clear that noise is a
significant hazard to public
health. Truly, noise is more than
just an annoyance.
23
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While this booklet contains reliable and
important information on Noise, it is not
published in support of any specific EPA
Noise Regulation. The technical supporting
documentation for any specific EPA Noise
regulation will be published in a background
document which accompanies the regulation.
"Calling noise a nuisance is like
calling smog an inconvenience.
Noise must be considered a hazard
to the health of people everywhere.'
Dr. William H. Stewart, former U.S.
Surgeon General
Cover Photo, Al Whitley
Page 4, Al Whitley
Page 7, H. Armstrong Roberts
Page 9, Al Whitley
Page 10, Linda Bartlett
Page 13, Al Whitley
Page 14, Paul Conklin
Page 17, Al Whitley
Page 19, Al Whitley
Page 21, Paul Conklin
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