Middle ear appeared in amphibians. Reptiles ... longer than that of reptiles. In mammals, a cartilaginous pinna is usually present about the external opening to amplify and channel sound waves.

Medically reviewed by John Carew, MD The ears are a pair of sensory organs whose primary functions are hearing and balance.

Part of the ear What it does Pinna This is the outer flap of the ear ... Ear Canal The pathway for the sound wave to the ear drum and the middle ear. Eardrum A thin, cone shaped piece of ...