Noise Hazards
UE News, June 1998
Noise is one of the most common hazards encountered by U.S.
workers. It is estimated that about 10 million U.S. workers are regularly exposed to
dangerous noise levels on the job.
This noise can cause damage to the sensitive cells lining the inner parts
of the human ear. When loud sounds damage your hearing, your ability to detect high
frequency sounds goes first. Initially you won’t notice the effects of this because
the sound frequency affected first is 4,000 Hertz, that is, 4,000 cycles per second. This
is higher than the ordinary sound frequencies of human speech (which go from about 200 to
3,000 Hertz), so your ability to hear other people’s speech and communicate with them
won’t be affected.
But if these loud sounds continue, your hearing will continue to
deteriorate. Within a few years your hearing will be damaged at the frequencies below (and
above) 4,000 Hertz. Eventually your ability to hear sounds below 3,000 Hertz will be
affected. Then you will begin having a hard time hearing what other people are saying to
you.
For example, you might not be able to understand a waitress in a noisy
restaurant, or hear what someone is saying to you at a noisy party. Perhaps you will have
difficulty hearing the doorbell or the phone ringing. since these are usually designed to
ring at high frequencies. Also, many consonants such as F, X and S, which have high
frequency sounds in them, become hard to distinguish. So you may not be able to tell the
difference between the words "fifteen" and "sixteen."
GET A CHECKUP
How can you find out about the earliest (4,000 Hertz) hearing losses, the
ones that happen before you begin to notice problems hearing others speak? The answer is
to have your ears checked by an audiologist. This is a person trained to measure the
ability of human ears to hear sounds over a wide range of sound frequencies. When this
person gives you an audiological exam, he or she will be able to pick up any hearing loss
at 4,000 Hertz long before you notice any loss. (The results of such a test are called an
audiogram.)
The next step is to work with your union to get management to quiet down
the noise in your shop. You can try to get a provision in your contract guaranteeing free
earplugs and earmuffs for those who want to wear them.
Audiograms are costly, but remember if noise levels on your job average 85
decibels or more (on the A scale of a sound level meter) then your employer is required by
law to give you an annual audiogram free of cost to you and during working hours. You must
also be given a full, confidential report of what the audiogram shows. Also, if the
average sound level you are exposed to exceeds 85 decibels, your employer must by law
provide (at no cost to you) earplugs or earmuffs, which you have the option of wearing.
(Above 90 decibels, the earplugs or earmuffs not only must be provided, they must be
worn.) When earplugs or earmuffs are provided by your employer, at any decibel level, they
must be fit-tested on you individually by a qualified person.
LEGAL EXPOSURE
How do you know if the sound you are exposed to is 85 decibels or more?
You need a meter to tell you exactly. And remember the sound must average above 85
decibels or more over an eight-hour workshift. You are legally allowed to be exposed above
85 decibels for a few minutes to a few hours, but over the whole workshift the average
must be 85 decibels or below. (As a rule of thumb, if you are in a room where you have to
shout at a person two feet away from you in order to be heard, then the sound in the room
is about 85 decibels.)
If the sound level averages more than 90 decibels during an 8-hour shift,
then your employer is in violation of the federal safety and health law. (Rule of thumb:
At 90 decibels you have to shout at a person whose ear is one foot away from you in order
to be heard.) Exposures between 85 and 90 decibels are legal, but you are entitled to a
free annual audiogram once the levels are 85 or more.
If a sound level meter is needed to measure noise levels, the union health
and safety committee or your local officers should ask management to provide one.
Sometimes a local COSH group can lend their meter to you, or a local clinic might have one
to lend. Remember, though, check the battery on the meter before you begin and check that
the meter has been calibrated before the measurement with a sound source of known
frequency and loudness. (Also, many people now use so-called sound dosimeters instead of
sound level meters. You wear these dosimeters on your lapel, usually, , and they give you
your personal average daily dose of sound at the end of the workshift. A dose of 1.0 over
an 8-hour shift corresponds to an average daily sound exposure of 90 decibels, and a dose
of 0.5 to a daily average of 85 decibels.)
WORKERS' COMPENSATION
Finally, if you have been exposed to loud noises on the job for many
years, say 10 years or more, you may be eligible to receive workers’ compensation
payments for partial permanent hearing loss. If you are showing unusual signs of hearing
loss as you age (we all lose some hearing with age, but exposed workers lose more and at
younger ages), ask your union officers for a referral to a workers’ comp lawyer. Only
10 percent of workers who have suffered a compensable hearing loss on the job ever apply
for compensation!
While loss of hearing won’t kill you, it can make communication with
family and friends very difficult, if not impossible. For many victims of hearing loss due
to noise on the job, this medical condition can lead to withdrawal, depression and even to
suicide in some cases. Hearing loss due to noise on the job is irreversible. Once the loss
has occurred, you can never recover your old hearing. So take noise on the job seriously,
and don’t let job-related hearing loss creep up on you. Almost all work situations
can be quieted when the employer is persuaded to do something about noise on the job.
