Normal Ear Anatomy & Hearing

The external ear consists of the pinna (visable ear)and auditory canal.

The middle ear consists of the tympanic membrane and three bones, or ossicles, know as the malleus, incus and the stapes.

The inner ear consists of the cochlea as well as organs for balance.

How We Hear

1.  Sound entering the ear canal causes the ear-drum to vibrate.

2.  The vibrations are transmitted through the ossicles (small bones) which intensify the pressure of the sound waves and transmit vibrations to ...

3.  the oval window, a membrane over the entrance to the cochlea. The simultaneous pulsating movements of the round window stabilize pressure within the inner ear.

4.  The fluid (endolymph) which fills the cochlea transmits the waves along the scala vestibuli and round into the scala tympani, making the basilar membrane separating them vibrate. This membrane contains hair-like receptor cells (organs of Corti).

5.  These produce nervous impulses which are sent along the cochlear nerve to the brain.