Source: Better Hearing Institute
Patricia E. Connelly, PhD, CCC-A, FAAA, New Jersey Medical School, NEWARK, NJ

The Hearing System

The anatomy of the hearing system can be divided into four components for our convenience in remembering the parts and associating these parts with their function. These divisions are the:

1.outer ear
2.middle ear
3.inner ear
4.central auditory pathways

The Outer Ear (1)

Several structures comprise the outer ear. The most readily seen is the pinna, also called the auricle. The pinna is made up of a frame of cartilage that is covered with skin. The pinna has obvious folds, elevations, depressions and a prominent bowl – all of which vary somewhat from person to person but a basic pattern in these features is fairly universal among all people. The pinna acts as a funnel to collect and direct sound down the ear canal. It also serves to enhance some sounds through its resonance characteristics. Finally, it helps us to appreciate front-back sound localization.

The other structure of the outer ear is the external ear canal. The outer two-thirds of this canal has a cartilaginous framework, and the inner one-third is bony. The skin of the external ear canal is continuous with the skin of the pinna. The ear canal is curved, almost “S” shaped and averages about 1 inch in length in adults. The skin of ear canal has hairs (more prominent in some people) and glands that produce wax called cerumen (also more prominent in some individuals than in others). This hair and cerumen serve a protective function for the ear canal. In addition, cerumen helps to lubricate the skin and keep it moist.

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