What Are the Hammer, Anvil, and Stirrup?

The hammer, anvil, and stirrup are three microscopic bones in the middle ear that convert airborne vibrations into fluid motion inside the inner ear. Collectively called the ossicles, they form a lever system that concentrates and amplifies sound from the eardrum to the inner ear. This article explains their anatomy, how they work, what can go wrong, and how hearing is preserved or restored when the ossicles are affected.