We talk a lot about safety when it comes to Motorcycle Riding, a great deal of attention is paid to motorcycle safety by the government, motorcycle industry, and media. However, the subject of hearing loss among motorcyclists is rarely discussed. This owes mostly to the fact that, we actually pass it on as something, which we do not concentrate on.
The most common kind of hearing loss is the exposure to excessive noise, and the simple act of riding a motorcycle puts riders at risk for becoming part of those statistics. The wind noise at highway speeds can expose motorcyclists to sound levels in excess of 100 dB – that’s the equivalent of using a chain saw or standing in the middle of a dance club. Helmetless riders can experience noise 10 times greater than that, resulting in potential hearing loss in as little as 30 minutes.
Hearing loss may be caused by effect of excessive noise. It is called Noise Induced Hearing Loss (NHIL) , and it is extremely necessary to understand that this is permanent, when it happens, it stays permanent, the good thing being, it is preventable. There have been a great deal of research done on NIHL in the workplace and there are rules regarding what is an acceptable eosure duration to various levels of noise.
Thus. When we ride motorcycles, we need to understand the various levels of noise we can face and then make educated decid=sions on how to minimize the long term risks of hearing loss. However, before we delve in to motorcycle-specific causes of NIHL, we should look at the physical causes of hearing loss so that we understand how noise damages our hearing.
In the ear, the air pressure waves that are the physical embodiment of sounds are converted by the ear into the electrochemical impulses that the brain can understand.
Noises that are too loud damage and ultimately can kill the hair cells. The amount of damage that occurs is time dependent and related to the intensity of the sound. While an extremely loud noise, like an explosion, can cause immediate, permanent damage, extended exposure to less loud but still damaging noise can also lead to permanent damage. Our goal, as motorcycle riders, is to determine the sound threshold that will allow us to take the long rides we enjoy and still be able to talk to our friends and family when we get home.
The noise that motorcyclists hear at highway speed is largely a function of turbulence. Recent studies have shown that the primary source of helmet turbulence – and noise – is in the chin bar of a full-face helmet. When these results were initially announced, the anti-helmet lobby latched on to the idea, saying it proved that helmets were bad for riders. However, if one considers the relative aerodynamics of the human head with its ears flapping out in the breeze versus the smoother, more aerodynamic shape of a modern full-face helmet, the fallacy of this argument is readily apparent.
An aside: Some studies have shown that certain helmet shapes and construction may amplify sounds of certain frequencies, which is not a good thing and may contribute to hearing loss. However, when compared to the full-on auditory assault of riding helmetless, using this factor as an excuse for not wearing a helmet is nothing more than a straw-man argument.
Wearing earplugs while riding is the best means of preventing NIHL. The cheapest and most common ear protection is foam earplugs which can be found at any local drug store. Foam earplugs come in a variety of shapes, from cylinders to tapered to bullet-shaped, but you insert them the same way: roll them into a tight cylinder and slide them into your ear before they expand.
When installed correctly, foam earplugs can effectively reduce noise to a level to allow all-day riding without any hearing damage. All brands of non-custom earplugs are required to include a Noise Reduction Rating (NRR) on their packaging. Claims of 32dB sound reduction are common with foam. When they get dirty – and they will – simply throw them away and open another package.
However, be forewarned, proper installation of foam earplugs is required for anything close to the NRR protection. People with narrow or oddly shaped ear canals will find that the softness that makes these plugs so comfortable to wear also makes it extremely difficult to get them completely inserted – grabbing the top of the ear and pulling it up and back is key to getting them fully implanted. These help in controlling the effect of high frequencies, which the high-frequencies are the first to be damaged from excessive noise.
Two areas of research hold the most promise for reducing the noise that motorcyclists experience at speed. The first is fairly obvious. Build helmets that are increasingly designed towards attenuating noise. Although helmet manufacturers are more frequently mentioning the quietness of their helmets – particularly premium models – when unveiling them for the public, until there is an accepted standard for measuring helmet noise, motorcyclists have no way to ascertain which helmets provide the most auditory protection.
Another area of interest in reducing NIHL for motorcyclists is the development of noise canceling technology. Active noise canceling could come in the form of speakers which use the destructive interference between sound waves to effectively cancel the ambient noise itself. Other passive ways to reduce helmet noise could be retractable ear muffs that form a tight seal over the ear, for protection like you see on airport workers or in shooting ranges.
While these developments will be interesting to watch, the best advice we can give riders about how to protect their hearing is to wear earplugs on every ride.