By Robert Snider, M.D.
“What did you say?” Hearing loss is something that most all of us will face sometime in our lives. Hearing losses are divided into two groups. Those that involve the outer ear, ear canal, eardrum, ear bones and middle ear space are called conductive losses. Those that involve the hearing organ with its contained hair cells and nerve fibers and the nerves leaving the ears are called nerve losses.
These nerve losses may be temporary from exposure to loud noise without adequate ear protection and involve things such as machinery, music or shooting. This may improve after a few days but still leave some residual damage. As we receive additional noise trauma it adds up to cause changes that do not improve with time and become permanent. There are also many other causes of permanent hearing loss. Physical blows to the head and ear area that occur in accidents such as auto accidents and industrial accidents may cause a permanent loss. Infections that are severe or recurrent may cause a permanent loss. There are even hereditary influences in some families that cause hearing to be absent or poor at birth. These influences may show up later in life also with some people getting more damage from similar noise trauma than others. These influences may also cause losses whose onset is earlier than expected in life and have a faster progression than expected. Even the normal aging process usually shows some loss of the hair cells and nerve fibers that produce the tiny electrical currents that our brains process to let us identify sounds.
Hearing works by sensing sound waves also known as sound vibrations in the air. The sound vibrations are concentrated slightly by the outer ear and funneled to the ear drumhead which vibrates a bone called the malleus(hammer) which then vibrates the incus(anvil) which then vibrates the stapes(stirrup). As this inner most bone moves it sets up waves in the fluid of the inner ear that move hair like cells which are also in the inner ear. As they are bent then rebound they send tiny electric current messages through the nerves connected to them to the brain where they can be compared to stored memories that let us understand the world of sound that surrounds us.
It is important that we prevent the things we can control such as noise trauma by avoiding as much loud noise as possible and by using adequate protection and limiting the amount of time when around the unavoidable. It is important to treat infections adequately to minimize the permanent loss these can cause.
We can restore many of the conductive losses with surgery or medications. But nerve losses require replacement with assistive therapies such as hearing aids which make sounds louder or surgery such as implants which replace some of the functions of the hearing organ(cochlea). These surgeries and therapies are done by specially trained physicians called Otolaryngologist and by specially trained individuals called Audiologists.
If your hearing suddenly goes down you should see your physician immediately so any long term loss can be minimized. The more usual problem is a gradual loss of hearing that sneaks up on us. We may not realize the loss is troublesome until some says “That TV is too loud” or “I’m talking to you!” If this happens bring it up on your next physical or contact your Otolaryngologist so it can be evaluated. They will try to restore and preserve as much of this important function for as long as possible.