Is it possible for pilots to communicate while flying at Mach 1+? I figure that they'd fly past their sound before it got into the radio, and it'd be the same way if they were trying to hear a radio communication. I've thought of every possibility I could think of, and the only conclusion I could come up with is that they don't comunicate while flying Mach 1+. So am I right, or is there just something I haven't thought about yet?