How We Hear
To understand hearing and hearing loss, we must first begin with how we hear. Sound waves are collected by the outer ear and directed along the ear canal to 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, fluid in the inner ear transmits the vibrations into the 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 auditory nerves to the hearing centre of the brain. This centre translates the impulses into sounds the brain can recognise.