How We Hear

Understanding hearing and hearing loss is easier by first learning how hearing works.  Sound waves are collected by the outer ear and directed along the ear canal to the eardrum.  When the sound waves hit the eardrum, the impact creates vibrations which, in turn, cause the three bones of the middle ear to move.  The smallest of these bones, the stirrup, fits into the oval window between the middle and inner ear.

When the oval window vibrates, the fluid in the inner ear transmits the vibrations into a delicate, snail shaped structure called the cochlea.

In the inner ear, thousands of microscopic hair cells are bent by the wave-like action of the fluid inside the cochlea.  The bending of these hairs sets off nerve impulses which are then passed through the auditory nerve to the hearing center of the brain.  This center translates the impulses into sounds the brain can recognize.