1. Ch. 13
Sound

2. Harmonics
Fundamental frequency – lowest possible frequency of a standing wave
Harmonics are multiples of the fundamental frequency

4. Standing Waves on a Vibrating String

5. A violin string that is 75 cm long has a fundamental frequency of 440 Hz. What is the speed of the waves on this string?

6. Standing Waves in Air Columns
2 types
If both ends of a pipe are open, then all harmonics are present

7. If one end of a pipe is closed, only odd harmonics are present

8. What are the first three harmonics in a 2
What are the first three harmonics in a 2.45 m long pipe that is closed at one end? Assume the speed of sound in air is 345 m/s.

9. Harmonics account for sound quality, or timbre
Timbre (‘tam-ber’)- the mixture of harmonics that produces the characteristic sound of an instrument

11. Fundamental frequency determines the pitch
The other harmonics are referred to as overtones
Beats
Sound waves at slightly different frequencies produce beats
The number of beats per second corresponds to the difference between frequencies