An illustration shows various parts of an ear that are marked as Hammer Anvil, Cochtea, Auditory nerve, Stirrup, Eardrum, and Ear canal. The Anatomy of the Ear are:

• Outer Ear: The part of the ear you can see funnels sound waves down the ear canal, a tunnel about 2.5 cm long. There, sound waves strike the eardrum, a tightly stretched membrane between the outer and middle ear. The eardrum vibrates at the same frequency as the sound waves striking it.
• Middle Ear: The middle ear contains three tiny bones—the hammer, the anvil, and the stirrup. When the eardrum vibrates, the hammer vibrates at the same frequency. The hammer strikes the anvil, which in turn moves the stirrup back and forth. The three bones act as a lever system to amplify the motion of the eardrum.
• Inner Ear: Vibrations from the stirrup travel into the cochlea, a spiral-shaped canal filled with fluid. The inside of the cochlea is lined with thousands of nerve cells with tiny hair-like projections. As the fluid in the cochlea vibrates, the projections sway back and forth and send electrical impulses to the brain.