The middle ear starts with the tympanic membrane. As sound waves traveling down the ear canal reach the tympanic membrane, it vibrates like a drum.
Behind the eardrum is an air-filled space containing three tiny bones; the malleus, incus and stapes. They are the smallest bones found anywhere in the human body. The vibrations in the eardrum, in turn, cause these bones to vibrate. The middle ear consists of the eardrum, malleus, incus, stapes, and the air pocket in which they reside.