Is the speed of sound the same in a moving current of air and still air? If not why?

Question

Please explain the speed of sound in a moving current of air in both directions, against the current speed and in the same direction as the moving current of air. Will two standing people in the two directions, at the same distance from the sound source receive the sound at different times?

Answer 1

  The speed of sound stays the same in a current of air what can change is the pitch,you know the siren coming and going

  High frequency or low frequency travels the same speed.

Answer 2

The speed of sound varies depending on the density of the air! I water it travels a lot faster than in air because water is much denser than air!

Answer 3

The speed of sound is always the same, as long as density and chemical composition stay the same. But the velocity of a object as multiple of the speed of sound or the propagation of sound within a medium depends on the flow velocity of the medium. Sound propagates inside a medium and thus the speed relative to the medium is important, not a absolute speed.

When you stand still in a wind tunnel producing 0.5 Mach, the effects will be the same for you as if you are moving at 0.5 Mach over fixed ground.

So, when you measure the propagation of sound during a Hurricane (about Mach 0.25), you will have of course have differences in how fast the sound propagates relative to the ground. The propagation is equal relative to the moving air, but the air moves relative to the ground.