Bones in the middle ear of vertebrates, which connect the eardrum to the inner ear. They transmit vibrations of the eardrum caused by sound waves in the air to the fluid of the inner ear via the oval window. Three ossicles, the malleus (hammer), incus (anvil), and stapes (stirrup), are present in the mammalian ear. They form a lever system, diminishing the force of sound waves and increasing the force on the inner ear. A single ossicle occurs in the ear of birds, amphibians, and reptiles.
