What Is the Middle Portion of the Ear?

According to Encyclopedia.com, the middle ear is a cavity within the skulls of vertebrates that lies between the external ear and the inner ear.

Features

• While often described as an empty space, the middle ear contains the tympanic membrane, or ear drum, and three small bones known as ossicles. These lie adjacent to the ear drum and are attached to it as if by a chain.

Identification

• The central part of the ear apparatus is connected to the nasopharynx, or back of the throat and nose, by the eustachian tube, which equalizes air pressure.

Function

• The three small bones, known as the incus, malleus and stapes, move because of sound waves that vibrate the tympanic membrane. The stapes fills the oval window, the area from which the ossicles transfer vibrations to the inner ear.

Significance

• The middle ear functions by matching low-impedance airborne sounds to the higher-impedance liquids of the inner ear. Impedance refers to a substance's resistance to movement.

Warning

• According to the Centers for Disease Control and Prevention, fluid occasionally finds its way into the middle ear through infection. These cases are often treated with oral antibiotics and some fluid may remain for up to a month.