The Human Ear

The human ear is a complex organ that provides us with our sense of hearing and balance. There are three distinct anatomical parts to the ear that enable us to experience the sense of hearing: (1) the outer ear which includes the pinna (the fleshy visible part), the auditory canal and the outer portion of the tympanic membrane; (2) the middle ear which contains the inner portion of the tympanic membrane, the middle ear cavity, the ossicular chain, the stapedius muscle and the upper terminus of the Eustachian tube; and, (3) the inner ear which contains the cochlea, a tiny, snail-shaped structure that reaches full growth by the ninth week of gestation. The cochlea transforms the sound pressure impulses that enter the outer ear into electrical impulses that are taken to the brain for interpretation by the eighth cranial nerve (aka, the vestibulocochlear nerve made up of the auditory and vestibular nerves). A second part of the inner ear, the semicircular canals, in conjunction with other systems within the body, enables us to have a sense of balance.

Hearing is the first of our five senses to develop - in the eighteenth week of gestation. Because it accounts for more than 80% of the stimuli that reaches the brain it is considered the most important of our sensory mechanisms. As humans we depend on our hearing for our cognitive and psychosocial development, safety, language perception and development, social relationships and our general well-being. Failure of our hearing "system," or hearing loss as it is commonly described, can result in a severe physical, psychosocial and emotional handicap.

Our ability to sense balance is a direct function of the correct working of the semi-circular canals aided by our ocular (vision), musculoskeletal, and the nervous systems. Meniere's disease (idiopathic lymphatic hydrops) is symptomatic of a failure of the integrated balance system to function properly.

The ear and the proper functioning of its components are a vital part of our well-being.