Picture courtesy of Cochlear Ltd.
Here is how the ear works normally:
- Sound is transmitted as sound waves from the environment. The sound waves are gathered by the outer ear and sent down the ear canal to the eardrum.
- The sound waves cause the eardrum to vibrate, which sets the three tiny bones in the middle ear into motion.
- The motion of the bones causes the fluid in the inner ear or cochlea to move.
- The movement of the inner ear fluid causes the hair cells in the cochlea to bend. The hair cells change the movement into electrical pluses.
- These electrical impulses are transmitted to the hearing (auditory) nerve and up to the brain, where they are interpreted as sound.