Anatomy of the Ear
and the Effects of Aging

The outer ear includes the external part of the ear and the ear canal

The middle ear is separated from the outer ear by the ear drum and contains three tiny bones called ossicles

The inner ear serves two functions - the cochlea for hearing and the semicircular canals for balance

How do we hear?

1. Sound waves are collected by the pinna /auricle (the external visible ear).

2. These sound waves are directed down the ear canal where they reach the eardrum (tympanic membrane).

3. The ear drum vibrates with these sound waves, causing the ossicles, referred to as the hammer, anvil, and stirrup, to vibrate.
   

4. The ossicles carry the vibration to the cochlea, a fluid filled snail shaped structure in the inner ear.

5. The cochlea is filled with thousands of tiny hairs called cilia, which are attached to nerve cells.

6. As the liquid in the cochlea vibrates, it moves the cilia which stimulate the nerve cells to send different signals to the brain via the auditory nerve.

7. The brain receives the signals,distinguishes them, and translates them into the sound we hear.

The effects of aging on the ear

• The eardrum thickens

• The tiny bones in the middle ear stiffen

• Loss and breakage of hairs(cilia) in the inner ear

• Nerve function decreases

• The brain's ability to translate sound signals slows down

Read about Hearing Loss
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