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UAW-GM HEALTH and SAFETY
SUPERVISOR’S SAFETY TALK
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NOISE/HEARING
Let’s take some time to think about the importance sound plays in our lives, and the things we can
do to conserve and protect our hearing. Do you like to listen to your car radio, turn on the stereo for
entertainment, or spend time on the telephone? Is conversation with family and friends an important
part of daily life? Does your job involve discussions with others? All these activities are so
commonplace and expected that our ability to hear and participate is seldom appreciated. Rarely are
we in an environment void of sound, or in a physical state in which our sense of hearing turns off.
Even in a quiet place we often hear the subtleties of life... the whisper of wind, the movement of
water, the hiss of the air around us. Most emergency alarms... fire, smoke and others are predicated
on our ability to “hear”... even when we sleep. These brief references should prove that “hearing the
world around us” is a blessing few of us would care to lose, and an asset worth protecting.
Hearing conservation and protection are not new elements of our safety program. Every year, in
fact, we revisit them to update you on any changes that may have occurred. We believe it is
important to remind everyone about the effects noise can have on your ability to hear, and review the
purpose of audiometric testing and hearing protection. We will also discuss the type(s) of hearing
protection available at our location, how effectively each reduces noise exposure, and how you
should select, fit, use and care for your hearing protection.
The best way to understand hearing loss, and gain insight on prevention of hearing loss is to return
to basics. “Sound” is energy transmitted through the air in a vibrating pattern called sound waves.
Noise is merely unwanted sound. Sound is measured by its frequency and intensity. Frequency is
the pitch of a sound, or the number of sound wave cycles per second. The general range of
frequencies that can be heard by the human ear falls between 20 and 20,000 cycles per second. The
intensity, or loudness of sound, is measured in units called decibels. The higher the decibel
reading... the louder the sound.
Sound waves, produced when the air is mechanically disturbed, enter the ear canal and cause the ear
drum to vibrate. These vibrations pass through three small bones in the “middle ear” and set fluid
moving in the “inner ear”. At least 30,000 delicate hair-like cells in the inner ear pick-up the
vibrations and convert them to nerve impulses that the brain interprets as sound... thus we hear. If
the environment around us contains an excessive amount of sound energy or “high noise” over
extended periods of time, some of the hair-like cells of the inner ear can be damaged to the point that
hearing loss can result.
With these facts in mind one might ask.... “How loud can a sound be?”... or, “How long can a sound
last before it results in hearing loss?” The answer is... no one really knows. There are too many
variables among people to pinpoint the exact volume, or exact period of exposure, at which any one
person will begin to lose his or her hearing. For the most part, however, at least in the industrial
setting, it is normally expected that people without any history of hearing loss can be exposed to
sound levels, or “noise” of up to 90 decibels (on a time weighted average), for eight hours a day,
without unacceptable risk. The problem with this formula is that the sounds we hear outside the
workplace are always added to our overall tolerance. If we follow good hearing conservation and
hearing protection practices at work, and then sit “front/center” at rock concerts, or really BOOM
the box at home,... our quality of hearing will remain at risk. The point is, a hearing conservation
program, “your hearing conservation program” must be a full time process, both on and off the job.
Do you have a hearing problem? There are several warning signs that may help to identify the threat
of hearing loss. They are:
* An inability to hear high pitched or soft sounds.
* Difficulty understanding normal conversation with someone two or three feet away.
* Prolonged ringing, roaring or other unusual head noises (tinnitus).
* Trouble understanding telephone speech or listening to radio or television.
In addition to the loss of hearing, excessive noise may also cause mental annoyance, physical stress
and fatigue.
At work, Plant Leadership, the Local Joint Health and Safety Committee, the Plant Noise Abatement
Committee, Engineering, Supervision and members of the Shop Committee all have responsibilities
for the reduction of noise in the workplace.
Noise can be reduced through maintenance of equipment, improved work methods and applications
of specific noise abatement techniques for eliminating, containing, dampening, muffling or
absorbing unwanted sound. Substituting mechanical ejection devices for air blow-off equipment can
reduce noise. Application of sound enclosures around high noise equipment or processes can
minimize or eliminate noise exposure for many workers. Using quiet air nozzles can diffuse noise
energy from compressed air release, or exhausts can be routed into the framework of a machine,
press or building structure to eliminate noise. Use of non-metallic materials to construct chutes, bins
and parts containers can eliminate the noise of parts striking or vibrating against them during
manufacture or transfer. Even coating the walls or floors with sound absorbing materials can go a
long way to reduce noise in a work area.
While Engineering noise controls are the preferred method of reduction of noise exposure, they are
at times not feasible, applicable or successful in meeting the desired result. The answer, or at least
the interim answer, in these situations is to warn you of the potentially harmful exposure to noise in
a specific location, and provide you with effective hearing protection. At this time I will review our
Local Plant Policy for the identification of High Noise Areas, and the type(s) of hearing protection
approved for use at this facility. I will also explain how they are to be used, when they are to be
used, their noise reduction rating, and how to care for and/or replace your hearing protection.
From a very practical standpoint, we advise the use of hearing protection during any work, activity
or situation... on or off the job, that would subject you to loud sounds or prolonged noise exposure.
There is everything to gain and nothing to lose with the use of ear protection.