How Does the Damage Occur?
As mentioned earlier, sound is converted from
an airborne vibration to wavelike fluid motion in the inner ear. The
motion of the fluid in the cochlea stimulates the hair cells that send
electrical impulses to the brain. It may be helpful to think of the
hair cells in the inner ear as reeds in a pond. On a calm day with the
wind blowing lightly the reeds sway back and forth in the breeze. On a
stormy day the wind blows so hard that the reeds in the pond are forced
down flat. Depending on the length or severity of the storm, a number
of these reeds will gradually return to their normal condition, but
others will have been broken and will not recover. Repeated exposure to
loud noise fatigues the hair cells in the inner ear. Just like the
reeds, some of these hair cells will return to the normal position, but
others will have been damaged beyond the point of recovery. The
destruction of these hair cells is evidenced by permanent hearing loss.
Noise induced hearing loss typically occurs gradually and without pain.
Often by the time a person realizes that there may be a problem, it is
too late. But there are early warning signs.
If you experience any of the following symptoms, have your hearing tested by a Hearing Health Care Professional:
-A ringing or buzzing (tinnitus) in the ear immediately after exposure to noise.
-A slight muffling of sounds after exposure, making it difficult to understand people after you leave a noisy area.
-Difficulty understanding speech; that is, you can hear all the words, but you can't understand all of them.