There is a misunderstanding associated with “clap”, caused by a misunderstanding of the term “sound barrier”. This “clap” is correctly called “sonic boom”. An airplane moving at supersonic speed creates shock waves in the surrounding air, jumps in air pressure. Simplified, these waves can be imagined in the form of a cone accompanying the flight of the aircraft, with the top, as it were, tied to the nose of the fuselage, and generatrices directed against the movement of the aircraft and propagating quite far, for example, to the surface of the earth.
When the boundary of this imaginary cone, denoting the front of the main sound wave, reaches the human ear, then a sharp jump in pressure is perceived by ear as a clap. A sonic boom, like a tethered one, accompanies the entire flight of the aircraft, provided that the aircraft is moving fast enough, albeit at a constant speed. A clap, on the other hand, seems to be the passage of the main wave of a sound boom over a fixed point on the earth's surface, where, for example, the listener is.
In other words, if a supersonic aircraft with a constant but supersonic speed began to fly back and forth over the listener, the pop would be heard every time, some time after the plane had flown over the listener at a fairly close distance.
