How does pressure affect speed of sound?

Answer 1

Speed: Wind (which is created by the earth's rotation) is the air being pushed by the earth's movement. Air, just like any solid, liquid, or gas, will have a velocity when in motion. that velocity will go against any velocity moving in the opposite direction. for example, if you're running in track, and you feel the wind pushing towards you, that's your velocity against the winds (usually the wind wins, or at least increases your time). Sound: Sound waves rely on molecules to move. that's why sound is impossible in space. a star can explode and nobody hears it. When, say, a police car rushes pass you with sirens, it pushes with it the air molecules into that > shape. picture this diagram. [=] >. The [=] is the car, the > is the molcules being pushed by the car, and you're the . the air molecules move towards you in that shape, and when the end of the > touches you, you finally hear the sirens. if the car is driving into wind, the wind pushes the air back <--- that way, so again, it's velocity against velocity. so if again we go back to that diagram, and the air is pushing in the opposite direction of the car, you'll hear the sirens later. sorry if my answers dont make sense.

Answer 2

The speed of sound changes clearly with temperature, a little bit with humidity − but not with air pressure (atmospheric pressure).

The temperature indication, however, is absolutely necessary.
Changing of the air pressure does not change the sound of Musical Instruments in concert halls or in a rooms.