By Craig Olson, M.D.
Originally Published in the IAMC Newsletter, October 2010
The riding motto ATGATT (All The Gear All The Time) should not only apply to protective body gear, but should also be extended to hearing protection. While motorcycles have been around since the latter part of the 19th century as a mode of transportation, it has only been since the mid 1970’s that studies have demonstrated the relationship between hearing loss and wind noise in motorcyclists [1]. Despite this well-known relationship, many motorcyclists still do not take appropriate measures to protect their hearing.
Take it from Fred Rau, a writer for the motorcycle magazine Friction Zone, when he says, “If you ride a motorcycle without using hearing protection, you WILL, in time become at least partially, if not totally, deaf…I am currently learning the hard way [2].” He celebrated his 60th birthday with a new pair of hearing aids as a result of noise induced hearing loss from riding motorcycles for many years without appropriate hearing protection.
Dr. Mike Coley, an otolaryngologist (ears, nose and throat surgeon) who has been riding motorcycles since age 11 and remains an avid rider, having owned and ridden over 40 different motorcycles during his life, confirms that noise induced hearing loss from riding motorcycles without appropriate ear protection is not a “maybe will cause,” but is a “it will cause” situation. How much damage and how long it takes to show up is unpredictable with some individuals showing much more susceptibility than others when exposed to the same conditions [3].
Known as the silent killer, wind noise (not engine, exhaust or surrounding traffic noise) is the primary culprit causing hearing loss in motorcyclists. According to OSHA’s regulation of industrial noise exposure, an average worker surrounded by noise levels around 85-90 decibels (dB) for an 8-hour day will not exceed the limits of exposure time during a 24 hour period that will cause hearing damage. As the sound level increases, the length of exposure before damage to hearing occurs significantly decreases as depicted in table 1 below [4,6].
Wind noise around a helmet (even with the very best full-face helmets) still measures about 90 dB at 36 mph and about 110 dB at 96 mph. Many helmets actually resonate as they vibrate from the passage of wind around them, creating low frequency sound waves that can’t be heard by the human ear, but which can damage your hearing even more severely than the wind noise they are blocking out [2]. Without any helmet these noise levels are much higher. Neither the riding position nor the brand or style of motorcycle (faring, wind screen, etc.) makes significant difference in noise levels. 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. Long-term exposure to noise levels over 90dB can cause gradual hearing loss and regular exposure to 110 dB or greater for more than one minute can lead to noise induced hearing loss that is permanent and can only be treated by the use of hearing aids [5].
For perspective normal conversation is rated at about 55 dB, heavy traffic is rated at 90-100 dB, and a rock concert or chainsaw is rated at 110-120 dB. The range of human hearing is from about 20 Hz or cycles per second (a very low tone) to about 20,000 Hz (a very high tone).
So what is the best form of hearing protection when riding a motorcycle? Gary Prickett at Motorcycle Consumer News recently reported the results of testing a wide variety of earplugs comparing custom versus universal fit and foam versus silicone to determine which was best [5].
Scientifically measuring noise attenuation, acoustic fidelity, comfort and value, the audiologists conducting this study concluded that Leight Laser Lite, Hearos, and the Leight Max Foam earplugs are a cut above the rest of the earplugs. They were effective and comfortable while also being inexpensive and disposable foam plugs. Of the silicone-based earplugs, the Alpine MotoSafe Professional Driver’s Ear Plugs and Mack’s moldable earplugs demonstrated a reasonable compromise between noise attenuation, audio fidelity, cost, quality, and comfort.
Most of these earplugs can be purchased off the Internet at the Ear Plug Superstore [ http://earplugstore.stores.yahoo.net/ ], and some can also be found at most major drug stores.
Just as important as using proper hearing protection is how to properly insert earplugs. The only way to obtain the full benefit of any type of earplug is to assure that they are properly inserted into your ears. For this to occur, most or all of the plugs should fit within the ear canals. If half or a plug is projecting out of the ear canal, the benefits of the earplug are next to nothing. The technique for fitting formable foam earplugs is to: (1) Roll the foam between the thumb and forefinger of the hand on the same side of your body as the ear that is to receive the plug. The plug should be compressed into a small, smooth cylinder. (2) Reach over the top of your head with the opposite hand, and pull back and up on the top of your ear thus straightening the ear canal so the plug can be fully inserted. (3) Insert the tightly rolled plug into the straightened ear canal pushing the earplug in and down toward your nose with your index finger. (4) Hold the plug in place for a few seconds as your hear and feel the plug expanding to fill your ear canal [5]. You may need to experiment with different sized earplugs to find the one that results in a tight seal. An excellent 3-4 minute video demonstrating this technique is found at the Ear Plug Superstore web site and is worthwhile for every rider to review [http://earplugstore.com/videos/how_to_fit_foam_e arplugs.htm ].
References:
1. McCombe, A.W., Hearing loss in motorcyclists: Occupational and medicolegal aspects. J R Soc Med. 2003; 96: 7-9
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC539364/
2. Rau, F., Can You Hear Me Now? Friction Zone. March 2009.
3. Coley, M., Ear Plugs and Motorcycle Riding.
http://www.ridemyown.com/articles/safety/earplugs.shtml
4. Hearing Loss?!
http://www.rcmedic.com/know.asp
5. Prickett, G., Scientific Earplug Testing. Motorcycle Consumer News. September 2010; 2427.
6. Occupational Health and Safety Industrial Noise Levels. http://www.ohsonline.com/articles/2007/09/industria l-noise-control.aspx