1. travels fastest through solids
2. is slower than light
3. is a form of energy
4. cannot travel through empty space
5. has a high pitch when produced by an object vibrating rapidly
6. is absorbed in materials with soft, uneven surfaces
7. an echo is reflected sound that is heard again
8. sonar determines the depth of water and locates objects in the sea

9. hard, smooth surfaces usually reflect sound waves

1. the auditory nerve carries the message of sound to the brain
2. the lowest frequency a person can hear is 20 times per second
3. the middle ear includes the hammer, anvil, and stirrup
4. the vibrations of the larynx produces speech
5. the cochlea is the snail-shaped part of the ear which contains the actual organ of hearing
6. two ears are better than one because they help you tell which direction a sound is coming from

7. the highest frequency a person can hear is 20,000 times per second

8. vocal cords produce speech when they vibrate

1. bats and dolphins hear the highest frequency sounds
2. mammals are the only animals that have outer visible ears

3. dolphins and bats hear 120,000 vibrations per second

1. Alexander Graham Bell – telephone
2. Robert Boyle – proved sound waves travel only through matter
3. Thomas Edison – phonograph
4. Lazzaro Spallanzani – determined that bats can "see" with their ears

Sonar – used in determining the depth of the water and locating objects in the sea

Two ears work better that one because they help you tell what direction a sound is coming from.

Outer ear – made up of the auricle (the fleshy part that is visible), and the auditory canal

Middle ear – includes three small bones that are joined together: hammer, anvil, and stirrip

Outer ear – contains the cochlea (a snail shaped organ filled with fluid), and the auditory nerve