People who hear normally assume that all hearing impairments are like listening to a stereo set turned very low. There is a good chance that surgery can cure this type of hearing problem and that a hearing aid will help quickly and easily. Other hearing problems are more difficult. It is better simulated by listening to a news broadcast with the dial turned slightly off-station so that words are heard but are difficult to separate. Surgery cannot help, hearing aids may not be effective, background noise is especially distracting and disturbing, and increasing volume will not help.
Clarity is what is lost.
The human ear is capable of recognizing over 350,000 separate sounds. The ear canal funnels these sound waves to the eardrum and passes them on through the middle and inner ear for final interpretation in the cochlea. The cochlea is filled with a fluid and 25,000 tiny hair cells, each tuned to a specific pitch frequency which are sent to the brain as intelligible sounds. Loud noises and aging can damage these hair cells. It becomes difficult to distinguish between such words as chew, shoe and sue.