Friday, 6 February 2009

Motorcyclists - hearing protection..

Motorcycles and your hearing - some interesting (and worrying) Facts

Most motorcyclists understand the effects of dangers associated with the time spent enjoying 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 face helmets. However, this is only true to a certain degree.

Based on several research studies, the major contributor to hearing loss amongst motorcyclists is what's know 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 suitable 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 noise levels will gradually lead to the rider becoming another statistic.

To put this in perspective, according to OSHA's (USA equivalent of the UK's Health and Safety Executive) 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 motorway and trunk road speeds can measure up to 103dB, or comparable to a running chainsaw. At these levels the rider is not only tiring physically from the excess noise exposure, but it also puts him into the 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 fairing or windshield can help in preventing in relieving some of the noise and buffeting effects. 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 open faced helmets, 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 earpods 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 speakers, which allow for stereo compatibility or intercom communications. 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). for more

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