How We Hear

Ever wondered how we hear?

• What happens in our ear–when the door bell rings?

–when a dog barks?

–when someone is talking?

Objectives

• Learn the parts of the ear

• Understand how sound is processed

Basic Anatomy and Physiology of the Ear

Three parts of the ear

• Outer ear

• Middle ear

• Inner ear

How do we hear?

#1 Outer Ear

#1) The outer ear consists of the ear canal and eardrum. Sound travels down theear canal, striking the eardrum and causing it to move or vibrate.

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How do we hear?

#2 Middle Ear

#2) The middle ear contains three small bones called ossicles. This chain of tiny bones is connected to the eardrum at one end and to an opening to the inner ear at the other end. Vibrations from the eardrum cause the ossicles to vibrate which, in turn, creates movement of the fluid in the inner ear.

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How do we hear?

#3 Inner Ear (Cochlea)

#3) The movement of the fluid in the inner ear or cochlea, causes changes in tiny structures called hair cells.

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How do we hear?

#4 Auditory Nerve

#4) This movement of the hair cells sends electric signals from the inner ear up the auditory nerve (also known as the hearing nerve) to the brain.

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How do we hear?

#5 Brain#5) The brain then interprets these electrical signals as sound.

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Summary

• Becoming educated about the ear and how we hear is the first step towards advocating.

• Knowing the anatomy of the ear helps us to better understand how we hear.

• Understanding how hearing is processed enables us to educate those who have hearing loss.