If you sit down at the butts on a rifle range, it's amazing to hear the rounds zip by and then a couple of seconds later hear the report of the shot.
What always amazes me is that the round could be 10 feet above your head as it goes by but your ears tell you that it only just missed by a few inches.
That's because the shockwave DID pass that close to you, and that's what you're hearing...the compression of the air caused by the object. Because of the high speed it moves far from the actual object before dissipating, unlike slower objects whose air disturbances are smaller, just like the wake of a boat being felt farther away the faster it goes.
The Jedi Master