Inner ear

The inner ear holds a group of linked fluid-filled chambers. The snail-shaped chamber, called the cochlea (KOK-lee-uh), plays a role in hearing. Sound vibrations from the bones of the middle ear transfer to the fluids of the cochlea.

Tiny sensors lining the cochlea, called hair cells, turn the vibrations into electrical impulses. The impulses go along the auditory nerve to the brain. This is where damage and hearing loss due to age, loud noises or medicine begin.

The other fluid-filled chambers of the inner ear include three tubes called the semicircular canals. The three bony canals lie at right angles to each other. They respond to motions of the head.

Hair cells in the semicircular canals feel the motion of the fluid when you move. The hair cells change the motion into electrical signals. The signals travel along the vestibular nerve to the brain. This gives you your sense of balance