Three small bones—the incus (anvil), malleus (hammer), and stapes (stirrup)—that lie in the mammalian middle ear, forming a bridge between the tympanum (eardrum) and the oval window. The function of the ossicles is to transmit (and amplify) vibrations of the tympanum across the middle ear to the oval window, which transfers them to the inner ear. Muscles of the middle ear constrict the movement of the ossicles. This serves to safeguard the ear from damage caused by excessively loud noise.