The Ear : The Classical World

Introduction

The Ear is the organ responsible for providing the body with hearing, equilibrium, and the maintenance of equal air pressure. It consists of three divisions: the external ear, the middle ear, and the inner ear.

The external ear, which is called the auricle (the little ear) or pinna (feather or wing), gathers the sound waves made by the displacement of air, and passes them through the external ear canal to the tympanum, the eardrum (tambourine).

The vibrations of the tympanum cause the little-bones of the middle ear, the ossicles, which get their Latin names from their shapes, the malleus (hammer), incus (anvil), and stapes (stirrup), to pass on these vibrations to the oval window. The otopharyngeal auditory, or eustachian, tube links the middle ear to the throat and the outside of the body, thus keeping equal air pressure.

The vibrations of the oval window in turn affect the fluids of the inner ear or labyrinth, which provide the receptors in the cochlea (so-called from its snail-like shape) and the semicircular canals with the appropriate information about hearing and equilibrium respectively. From there, sensory auditory nerves convey that information to the brain for interpretation.