Sound PPT

1. Sound
How does
sound work?

2. Sound: What is it?
Sound is a disturbance that
travels through a medium
as a longitudinal wave.

3. Interactions of sound waves:
 Reflection: Sound waves reflect
when they strike an object.

4. Interactions of sound waves:
 Reflection: Sound waves reflect
when they strike an object.
You hear this as an echo.

5. Interactions of sound waves:
 Reflection: Sound waves reflect
when they strike an object.
 You hear this as an echo.
 Diffraction: Sound waves “bend”
around corners or “squeeze”
through a door.

6. Interactions of sound waves:
 Reflection: Sound waves reflect when they strike
an object.
 You hear this as an echo.
 Diffraction: Sound waves “bend” around corners
or “squeeze” through a door.
 Interference: Sound waves may interact with
each other.

7. Speed of sound waves:
 Depends on the elasticity, density,
and temperature of the medium
the sound is traveling through.

8. Speed of sound waves:
 Depends on the elasticity, density,
and temperature of the medium
the sound is traveling through.
 Elasticity: the ability of a material to
bounce back after it is disturbed.

9. Speed of sound waves:
 Depends on the elasticity, density,
and temperature of the medium
the sound is traveling through.
 Elasticity: the ability of a material to
bounce back after it is disturbed.
 The more dense the medium the slower
sound travels through it.

10. Speed of sound waves:
 Depends on the elasticity, density,
and temperature of the medium the
sound is traveling through.
 Elasticity: the ability of a material to
bounce back after it is disturbed.
 The more dense the medium the slower
sound travels through it.
 The lower the temperature the slower
sound travels through a medium.

11. Speed of sound waves:
Air at room temp. = 343 m/s

12. Speed of sound waves:
Air at room temp. = 343 m/s
Fresh water = 1,509 m/s

13. Speed of sound waves:
Air at room temp. = 343 m/s
Fresh water = 1,509 m/s
Glass = 5,170 m/s

14. Properties of sound:
 Loudness: Describes your
perception of the energy of the
sound.

15. Properties of sound:
 Loudness: Describes your
perception of the energy of the
sound.
 Depends on distance from the source
and energy used to make the sound.

16. Properties of sound:
 Loudness: Describes your
perception of the energy of the
sound.
 Depends on distance from the source
and energy used to make the sound.
 Measured in decibels (dB).

17. Properties of sound:
 Loudness: Describes your perception
of the energy of the sound.
 Depends on distance from the source
and energy used to make the sound.
 Measured in decibels (dB).
 Intensity: The amount of energy a
sound wave carries through an area
each second.

18. Pitch
 A measure of how high or low a
sound is.

19. Pitch
 A measure of how high or low a
sound is.
 Pitch depends on the frequency of a
sound wave

20. Pitch
 A measure of how high or low a
sound a is.
 Pitch depends on the frequency of a
sound wave

21. Pitch
 A measure of how high or low a
sound a is.
 Pitch depends on the frequency of a
sound wave
- Low pitch
- Low frequency
- Longer wavelength
- High pitch
- High frequency
- Shorter wavelength

22. Sonar

23. Sonar
- An instrument that uses reflected sound
waves to find underwater objects

24. Sonar
- An instrument that uses reflected sound
waves to find underwater objects
- For example,

25. Sonar
- An instrument that uses reflected sound
waves to find underwater objects
- For example,

26. Sonar
- An instrument that uses reflected sound
waves to find underwater objects
- For example,
Animals use sonar or echo location to find their
prey; these sounds have such a high pitch or
frequency that the human ear cannot hear

27. Sonar
- An instrument that uses reflected sound
waves to find underwater objects
- For example,
Animals use sonar or echo location to find their
prey; these sounds have such a high pitch or
frequency that the human ear cannot hear

28. Sonar
- An instrument that uses reflected sound
waves to find underwater objects
- For example,
Humans use sonar
to locate or map
objects
Animals use sonar or echo location to find their
prey; these sounds have such a high pitch or
frequency that the human ear cannot hear

29. Doppler Effect:
 Definition: The change in frequency
of a wave as its source moves in
relation to an observer.

30. Doppler Effect:
 Definition: The change in frequency
of a wave as its source moves in
relation to an observer.
Lower pitch
Higher pitch

31. Blue Man Group Challenge!
 Blue Man Group
 You’re HIRED!
 So what am I supposed to do exactly?

33. Can I use or make an instrument
that already exists?
 No way! You could, if you really wanted
to…but wouldn’t you rather challenge
yourself to invent something never seen
before? C’mon, I know you can do it!
Besides, building a piano is really
complicated. And putting a piece of string
on top of a piano isn’t really
groundbreaking, either.

34. Let’s look at some examples!
 Let’s look at some examples!
 Awesome
 Not Awesome
 Shoe box with rubber bands attached
Oatmeal box with beads in it or paper on top
to create a drum
 Tambourines made from paper plates
 Bongos made from tubs and paper