# Relative velocity of sound

Relative velocity of sound.

As I know that speed of sound in medium is property of medium. And independent of source motion but depend on motion of audience or observer and motion of medium. But it is not clear to me. Please explain it.

• Speed of sound in a medium doesn't depend upon the speed of the observer. So what is your question exactly? – udiboy1209 Jul 30 '13 at 14:24
• @udiboy does speed of sound not depend upon motion of medium of propagation or audience. – Rahul kumar walia Jul 30 '13 at 18:56
• It does depend upon the speed of the medium, but not on the speed of the *audience*(observer). – udiboy1209 Jul 31 '13 at 13:32
• @ thats my point that how and why its depends upon the relative velocity of medium and observer. – Rahul kumar walia Aug 3 '13 at 9:11
• If speed of the sound does't depend on the speed of the observer then speed of the sound act something like speed of light. It is constant irrespective of observer. @udiboy – Self-Made Man Aug 3 '13 at 11:34

Have you heard of doppler's effect? Read this http://en.wikipedia.org/wiki/Doppler_effect

For eg. If a wind of $400 m/s$ is blowing eastward, and the speed of sound is $300m/s$, the sound waves travelling eastward will have velocity of $700m/s$ eastward, sound waves travelling westward will have a velocity of $100m/s$ eastward, and sound waves travelling northward will have a velocity of $\sqrt{300^2+400^2}=500m/s$ at an angle of $37^o$ to east.