How Sound Affects the Inner Ear

Diagram 1: The outer ear gathers soundwaves and directs them through the ear canal.

Diagram 2: Soundwaves vibrate the eardrum, where the ossicles (middle ear bones) transmit the vibrations the the inner ear.

Diagram 3: Inside the inner ear, the cochlea, a spiral structure, contains fluid and about 30,000 highly sensitive hair cells, which respond to frequency (pitch) and intensity (loudness) of sound.

Diagram 4: Three rows of outer hair cells and one row of inner hair cells are connected to nerve fibers that translate sound as electrical signals to the brain.

Diagram 5: Normal hair cells.

Diagram 6: Hair cells as they appear after permanent damage by excessive intensity or loudness of sound.