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.