How Does Noise Cause Hearing Loss

Noise causes hearing loss due to over exposure.  Long exposure to loud noises is not the only way hearing loss is caused.  Long exposure to medium-intensity noises causes hearing loss as well, though it is more gradual and, at times, less noticeable.  Almost any sound can cause hearing loss, from mowing the lawn, to a live concert, to listening to music through headphones, to working in a factory.  Any noise that is loud enough for long enough can cause hearing loss.

Older generations have a higher likelihood of having hearing loss due to exposure at work.  Hearing protection on loud work sites is now mandatory, but up until even 20 years ago, this was not the case.  The younger generations may not have workplace exposure hearing loss, but they are still just as likely to have hearing loss due to their social environments they are exposed to such as vehicles, music or concerts.

The reason hearing loss occurs is because the ear is trying to protect itself from the loud noise to which it is being exposed.  It does this by dampening the sound.  Sound enters the ear and travels down the canal to the eardrum.  The eardrum then vibrates, causing a chain reaction through the middle ear bones – the malleus, incus and stapes – vibrating the fluid in the inner ear, sending the sound to the cochlea.  The cochlea is a shaped like a snail with tiny nerve hairs in it.  Each section of the cochlea pertains to a certain frequency that we hear.  These little hairs move in response to the sounds we hear, bending and standing as needed.  However, when exposed to loud sounds for a long period of time these little hairs begin to become damaged, and, if exposed long enough, they will die, causing hearing loss.  Once these little hairs die, they are gone for good; they do not grow back or regenerate.

It does take time for the degeneration or death to these hair cells to occur.  It sometimes can take years and usually the person will not notice at first that hearing loss is occurring.  A person may develop tinnitus, a ringing, buzzing or even roaring sound in the ear, which is another indication of hearing loss due to exposure. 

Sudden hearing loss can occur due to exposure to a loud burst of sound, such as gun fire or an explosion.  Hearing loss is very serious and these are all reasons why it is very important to wear proper hearing protection when exposed to loud noise in and around the workplace and home.