The smallest bone in the human skeleton is the stapes (pronounced "stay-peas"). The stirrup-shaped bone is one of the three ossicles, or "tiny bones," of the middle ear; the others are the malleus and the incus.
The ossicles function to transmit sounds from the air to the bony labyrinth, the outer wall containing the vestibule, semicircular canals and cochlea. As sound waves vibrate the eardrum (tympanic membrane), they move to the attached malleus, where they are then transmitted through the incus to the stapes and ultimately to the vestibule of the inner ear. The absence of the ossicles results in moderate or severe hearing loss.