The Voice of Walls

The wall voices is more like a pressure waves around the on-air body planes, that waves were creeped with a sonic s peed to give a signal for the air to give away from the airplane strip line. If the plane movement with a sonic speed the plane will move together with a wall and bump against the air in front of the airplane.

There will make an astonish waves in front of the plane nose, upright toward the direction of fly, if the plane speed more than a sonic speed, the plane will cracked the wall and getting ahead of the voice wall.

The bump waves will transverse wide, conical-plot which are penetrate the air and it may sound like blast sound.

Meanwhile the passenger were relaks and they will not hear that blast sound outside the aero plane.