Noise induced hearing loss, what do we know about it? How do we hear? First, the sound vibrates the eardrum and the eardrum in turn vibrates the little bones we call the hammer, anvil and the stirrup. This vibration is sent to the cochlea, which is shaped like a snail and filled with fluid. This fluid starts to ripple and the little hairs, located on the inner surfaces of the cochlea, detect the waves and transmit the electrical signals to the auditory nerve and on to the brain to be decoded resulting in hearing. The mechanics of the ear are much more complex than this description but you get the gist. Loud sounds, over time, causes the fine hairlike projections that are in the choclea to die and they do not regenerate so the hearing loss is permanent and irreversible. And sound itself is measured in decibles (or dB) and the common range is from 0 dB which is the threashold of hearing to 140 dB which is the sound of a jet taking off or a rock band.
We've all used headphones at one time or another. Did you ever think about hearing loss due to your use of headphones? I know that I never did. But we know that heavy machine, lawn mower, and jackhammer operators all use foam earplugs in their ears to block the noise.
According to the NIH, (National Institute on Deafness and Other Communication Disorders, Noise Induced Hearing Loss, NIH Pub. No. 14-4233, Updated March 2014) noise induced hearing loss (NIHL) can happen immediately or gradually over time. In order for you to loose your hearing immediately, you would have to be near or in near proximity to a gun shot or explosion. The more incideous hearing loss, gradually over time, comes with constant levels of noise at 85 decibels (dB), or greater, for long periods of time (> 3-8 hours) without a break. This damage can happen at any age, from small children to the elderly can develop NIHL. “Aproximately 15% of Americans between the ages of 20 and 69—or 26 million Americans—have hearing loss that may have been caused by exposure to noise at work or in “leisure activities.”[1] Leisure activities can include target shooting, hunting, snowmobiles, listening to MP3 players at high volume through earbuds or headphones, or playing in a band. Here are some average decibel ratings on everyday sounds that we are exposed to; the humming of a refrigerator(45 dB), normal conversation (60 dB), city traffic (85 dB), motorcycles (95 dB), MP3 player at max volume (85 dB), siren (120 dB), and guns and firecrackers (150 dB). (NIH, March 2014) Not to mention the many veterans coming back from Iraq that have NIHL due to the guns and bombings (hearing loss is the #1 war wound). Thankfully, there are regulations now for noise levels in the workplace and if the noise cannot be controlled, ear protection must be provided.
Noise is something we all put up with everyday and sometimes it can get pretty loud. Earbuds introduce the decibles directly into the ear canal causing hearing loss. What can be done to avoid this noise induced hearing loss?
Some say that the maximum volume should, by law, be regulated in MP3 players. I don't agree with this approach as it's nearly impossible to enforce. However, here are some other suggestions that I believe are worth noting that might work such as noice blocking earbuds and noise cancelling headphones that reduce noise by “creating frequencies that obviate the noise at your ear.” (C│net headphones) Being able to keep the volume down, one should be able to hear more low level sounds in the music. . The surrounding noise levels are causing the listener to continually increase the volume on the average earbud or headphone to drown out background noises. ETYMOTIC RESEARCH INC.[2] has been researching the causes and prevention of NIHL for over 30 years and have come up with earbuds that fit
