Doppler Effect

1
Doppler Effect
2
Resting sound source
Frequency fs
V340m/s
Frequency fo
source at rest
observer at rest
3
Sound source moving toward observer




Observer hears increased pitch (shorter wave
length)
Frequency fo
Frequency fs
source
observer at rest
4
Sound source moving away from observer




Observer hears decreased pitch (longer wave
length)
Frequency fo
Frequency fs
observer at rest
source
5
Frequency heard by observer

• Source moving toward observer.
• Perceived wavelength
• With
• Observer

6
Observed frequency

• Source toward observer
• Increased frequency
• Source away from observer
• Decreased frequency