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Most motorcyclists understand the effects of a "silent killer"
which follows them every time they enjoy riding their bikes. Unfortunately, several people
still believe the causes of hearing loss are due to how loud the bike sounds, and/or that
it affects only the people who do not wear full shell helmets. This is true to a certain
degree.
Based on several research studies, the major contributor to hearing loss in the motorcycle
industry remains the "silent killer" known as "wind
noise." Generically termed as the amount of noise turbulence produced around the head
while the rider is in motion. Its inherited consequences result in irreversible hearing
loss damage over a period of time when adequate hearing protection is not worn.
Similar to the shooting and aviation industries, if this issue is not addressed correctly
from the beginning the amount of exposure to the inner ear is compounded every time the
rider ventures out on his/her bike for hours at a time. Constant duration of harmful level
noises gradually force the rider into becoming another statistic of the "silent
killer."
To put this in perspective, according to OSHA's regulation of industrial
noise exposure, an average worker surrounded by levels around 85-90dB for an eight hour
day will not exceed the limits of exposure time within a 24 hour period of time.
However, when the sound levels exceed 100dB, your exposure time is reduced
to two hours. When sound levels exceed 115dB, your exposure time is drastically reduced to
15 minutes. This puts riding a bike a whole other realm as "wind noise" at
highway speeds can measure up to 103dB, or comparable to a running chainsaw. At these
levels the rider is not only fatiguing physically from the excess noise exposure, but it
also puts him into a position of needing a hearing aid later in life.
Another common ailment of motorcycle riding is a condition known as "Temporary
Threshold Shift," commonly referred to as TTS by audiologists and hearing healthcare
professionals. TTS is caused by excessive noise exposure for a duration of time, which
drops your actual acute hearing pattern to a lower level temporarily. Meaning, your
hearing is less than what it was before the initial exposure. Continuous TTS exposure will
result in permanent damage.
Everyone has experienced this phenomenon at one time or another, whether
it is from going to loud dance halls, or concerts, or even work. Even some of today's
movie theatres can cause this to happen, but this is a specific certainty for
motorcyclists who disregard adequate hearing protection while riding their bike.
Riding position and style of windshield help in preventing "silent killers"
ability to fully be experienced. But even the best helmets on today's marketplace provide
little help when considering "wind noise" levels at normal highway speeds.
Obviously, this factor is increased in half shell models as well as skullcaps, but the
common helmets used in today's marketplace are designed to fit entirely over the head
providing a snug fit. These types of helmets have the best attenuation value (reduction in
noise) regardless of any airflow modifications done to the outside. But these helmets
still produce wind noise readings of 110 to 116dB's, from 35mph to highway speeds. When
reflecting back to the comparison chart, 116dB will only be suitable for 15 minutes of
riding a day. Not a lot of time to enjoy your hobby.... Is it?
Although there are several versions of hearing protection devices on the market, a
custom set of earmolds is still the best answer in suppressing sound. They provide
excellent attenuation values and are comfortable to wear for extended periods of time.
They can even be molded with high-grade transducers, which allow for stereo compatibility
or communications. To find out more about these products search under our "Product
Links" listed on the navigation bar.
We also suggest checking with your local state officials on the regulations of wearing
hearing protection. Several states have motorcycle laws regarding earplug use. For a quick
reference, see the AMA web pages on State Motorcycle Laws -
http://www.ama-cycle.org/roadride/road.asp.
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There is no significant difference in wind noise level as a
function of speed, no matter what the helmet brand or model (all being full coverage). |
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Neither the riding position nor the brand or style of
motorcycle make significant difference in noise level. |
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Padding inside the helmet, open or closed vents, or added
weather stripping on the helmet to alter flow patterns, does not significantly alter the
noise level in a helmet. |
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Stopped at a stop light at a busy intersection with your
helmet visor closed produces a sound level of 80-90dB SPL. (Lawn mower, loud restaurant
levels) |
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When not wearing a helmet, the wind noise at highway speed
is nearly 10 times greater than when wearing a full coverage helmet. |
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Below 30mph, machine, exhaust and environmental noises are
heard. Once speeds exceed approximately 30mph, wind noise dominates completely. |
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Some helmets resonate at approximately 500Hz, and actually
enhance wind noise. |
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Legal speeds of 65mph can produce wind noise levels at 103dB
SPL, (chainsaw, pneumatic drill). This noise is loud enough to cause TTS in your hearing,
tinnitus and permanent ear damage. |
We perform group hearing tests for Gun Clubs, Police departments, Fire
and EMS departments ( siren noise) and Motorcycle clubs. Call 1-800 231-1006
for a free quotation on group rates for IPS mobile testing for you members. |