How the Ear Works

The hearing system consists of three distinct areas; the outer ear, the middle ear and the inner ear.  Each part plays an integral role in directing acoustic signals to the central processing unit, the brain.

The outer ear

The Pinna, or fleshy part of the ear, catches sounds in the surrounding environment.  The sound waves are funnelled through the ear canal to the eardrum.

The middle ear

This air-filled space located behind the ear drum houses the three smallest bones in the body, the malleus, incus and stapes.  When sound waves strike the eardrum they cause it to vibrate.  This sets the middle ear bones into motion which then stimulate the inner ear.

The Eustachian Tube connects the middle ear to the throat.  This maintains the air pressure in the middle ear.

The inner ear

Sound vibrations are passed from the bones of the middle ear to a fluid filled organ called the cochlea.  Tiny hair cells in the cochlea are bent when the fluid moves.  These hair cells send electrical impulses to the brain via the auditory nerve and the brain interprets these messages as sound.

Hearing loss is defined based on which part of the ear is affected.