5.37. Hearing and the Ear http://www.ck12.org
FIGURE 5.74
- The outer ear includes the pinna, ear canal, and eardrum. These structures gather sound waves, funnel them
into the ear, and pass the vibrations to the middle ear. - The middle ear contains three tiny bones that amplify the vibrations as they transmit them to the inner ear.
- In the inner ear, the vibrations are changed to electrical signals by hair cells lining the cochlea. The electrical
signals then travel to the brain.
Vocabulary
- hearing: Ability to sense sound energy and perceive sound.
- sound: Transfer of energy from a vibrating object in longitudinal waves that travel through matter.
Explore More
At the following URL, review the information about the ear and hearing. Be sure to watch the hearing animation.
Then fill in the blanks in the statements below. http://www.bbc.co.uk/science/humanbody/body/factfiles/hearing/he
aring_animation.shtml
- The outer ear canal ends at the __.
- The __ is the cavity between the eardrum and inner ear.
- The snail-like __ is filled with fluid.
- The spiral organ of __ consists of hair cells.
- Nerve impulses travel along the cochlear nerve to the __.
- Because we have two ears, we are able to locate the __ of sounds.
Review
- Summarize how we hear sounds.
- Identify the structures of the outer ear and state their functions.
- The three tiny bones of the middle ear work together as a lever. A lever is a simple machine that may increase
the force applied to it. How does this relate to the function of the middle ear?