How the ear works. Three main parts of the ear


The outer ear

The outer part of the ear collects sound. Acting like a funnel, sound is collected at the Pinna (visible part of the ear) and travels through the auricle and the auditory canal, a short tube that ends at the eardrum.

The middle ear

The middle ear is an air-filled space that contains 3 tiny bones (known as ossicles), called the malleus (hammer), incus and stapes (stirrup). Sound waves that reach the tympanic membrane cause it to vibrate. This vibration is then transmitted to the ossicles, which amplify the sound and pass on the vibration to the oval window (a thin membrane between the middle and inner ear).

The inner ear

The inner ear contains 2 main structures — the cochlea, which is involved in hearing, and the vestibular system which is responsible for maintaining balance.

The cochlea is filled with fluid and contains the organ of Corti — a structure that contains thousands of specialised sensory hair cells with projections called cilia. The vibrations transmitted from the middle ear cause tiny waves to form in the inner ear fluid, which make the cilia vibrate. The hair cells then convert these vibrations into nerve impulses, or signals, which are sent via the auditory nerve to the brain, where they are interpreted as sound.