Before becoming recognized by the brain, sound waves must enter the auditory canal, go through the tympanic membrane (eardrum), and then enter the middle ear compartment.
Once there, the sound waves vibrate three bones known as the ossicles, which are made up of the malleus, the incus, and the stapes.
The stapes is the smallest bone in the human body.
The malleus is sometimes compared to a hammer, because it strikes the anvil-shaped incus. The vibrations then travel through the stapes.
The stapes can be compared to a tuning fork, as it has a horseshoe-like shape. The word means “stirrup” in Latin.
The two branches of the stapes, known as the inferior and superior crus, convey sound vibrations to the bone’s flat base.
From there, the vibrations enter the inner ear, where they are processed into neural data to be transmitted to the brain via the cochlear and the auditory nerve.
If the stapes becomes damaged, such as from severe head trauma, a person may lose some or all of their ability to hear. Because the ossicles are a chain of bones, this also holds true for the incus and malleus.