How does the ear work ?

Outer ear
the visible outer portion of the ear, the pinna- and ear canal

Middle ear
the eardrum and three tiny bones

Inner ear
the fluid-filled cochlea, which contains thousands of tiny sound receptors called hair cells...

For people with normal functioning hearing, the outer ear collects the sound waves and directs them to the eardrum. The sound is then changed into mechanical vibration of the eardrum. This vibration is transmitted to the three tiny bones of the middle ear that transfer the movement to the oval window, a membrane covering the entrance of the cochlea.

Motion of the oval window causes vibrations to ripple through the fluid in the inner ear, or cochlea.
The motion of the fluid causes thousands of hair cells (because of the tiny hairs they have on the top) to move and in turn an electrical signal is sent to the hearing nerve, which carries them to the brain where they are interpreted as sound.

The hearing system works constantly. The task of the hearing system is to transform sound waves into nerve impulses, which the brain is able to interpret.

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