1. Sound Review Answers

2. What is sound?
Sound is disturbance what travels through a medium is a longitudinal wave.

3. What must sound have in order to travel?
Sound must have a medium to travel through. A medium is a solid, liquid, or gas.

4. What does it mean when we say that sound waves are mechanical waves?
It means that they carry energy through the medium without moving the particles of the medium along.

5. What is :
Reflection: sound waves hit a surface and reflect or bounce back
Diffraction: sound waves can move through barriers, openings in barriers, and around corners
Interference: sound waves meet and interact with each other

6. An echo is_______________
A reflected sound that bounces off a hard surface

7. Define:
Constructive Interference: when sound waves meet and join forces which causes their amplitude to rise(strengthen)
Destructive Interference: when sound waves meet and the amplitude is reduced

8. Define:
Elasticity: the ability of a material to bounce back after being disturbed
Density: how much matter or mass there is in a given amount of space or volume.

9. How does temperature affect the rates at which sound waves travel?
Sound waves travel quicker at high temperatures than at low temperatures.
Low temperatures cause the particles to move more slowly.

10. Sound waves travel faster in a (1)____________ ________________ and more (2)_________________ material.
1: more elastic
2: dense

11. What is loudness?
Loudness describes your perception of the energy of a sound

12. What 2 things determine the loudness of a sound?
Amount of energy: the greater the energy the louder the sound.
Distance: the closer you are to the source of sound the louder it is.

13. What is intensity?
The closer the sound wave is to its source, the more energy it has in a given area.

14. What is pitch?
Pitch describes how high or how low the sound seems to a person

15. What is frequency and how is it measured?
Frequency is the number of complete sound waves passing a certain point in a certain amount of time.
It is measured in Hertz (Hz).

16. What determines the pitch of a sound wave?
Pitch is determined by the frequency of the sound waves.
Higher pitch= the sound waves are close together
Lower pitch= the sound waves are farther apart

17. How can you adjust the pitch of your sound?
When you stretch your vocal cords you produce a higher pitch because they vibrate quickly.
When you relax your vocal cords you produce a low pitch. They do not vibrate as quick.

18. What is the Doppler effect and give an example?
It is a change in the frequency of a sound wave as it source moves in relation to an observer.
Ex: a police siren sound louder as it moves toward you and then quieter as it moves away.

19. List the 3 parts of the ear.
Outer ear
Middle ear
Inner ear

20. Explain the path that sound travels through the air to your brain.
The ear canal directs the sound waves to the eardrum.
When the sound waves hit the eardrum it vibrates. This makes the hammer, anvil, and stirrup also vibrate.
Next the cochlea which has liquid inside it moves. This causes tiny hair cells to vibrate sending messages to the brain along the auditory nerve.

21. Describe 3 ways you can experience hearing loss.
1: injury to the eardrum
2: old age
3: exposure to loud sounds over extended length of time