Dave,
I'm afraid the sonic thing now has a life of its own, and this is not correct!
The change in the air flow field around an object is felt by that field at 1060 feet per second, which is the speed at which pressure is propagated in that air. Any change to the filed effects flow at other places in the field but the change ripples through the field at 1060 feet per second. Forget sound, forget noise. If you make a change in a flow field, that change announces itself at that speed, 1060 feet per second.