1. Sound and Hearing

2. Basic Facts Longitudinal wave Audible range (human): 20Hz – 20,000Hz

3. Wave equation for sound (Skip)

5. Wave Equation for Sound Summary

6. The bulk modulus for air

7. The bulk modulus for air (Alternative Method)

8. Speed of sound in air

9. Sound Intensity and Energy Flux (Skip) Energy flux is defined as the amount of energy passing through a unit surface area per unit time. Intensity is the average energy flux. Unit: Jm -2 s -1 =Wm -2 [Recall that Js -1 =W ]

10. Sound Intensity (Skip)

11. Sound Intensity and Energy Flux Energy flux: The amount of energy passing through a unit surface area per unit time. Intensity is the average energy flux. Intensity: Energy flux averaged over time Same unit: Jm -2 s -1 =Wm -2 [Recall that Js -1 =W ]

12. Intensity falls with distance

13. Simple Example on Intensity

14. The Decibel Scale

15. Examples

16. The Doppler effect Wavelength and frequency change when the source (or the listener) is moving.

17. Doppler effect equation

18. Doppler effect example