What Is a Sonic Boom?
A sonic boom is the thunder like sound or a loud explosive noise caused by the shock wave from a supersonic airplane, aircraft or other object travelling faster than the speed of sound. Supersonic means faster than the speed of sound.
When a plane is flying at ordinary speeds, it shoves waves of air ahead of it. When a plane travels at the speed of sound or faster, it out-races the pressure waves it creates. The air piles up into a cone-shaped shock wave that fans out behind the plane.
When a shock wave from a supersonic plane reaches the ground, people along the flight path hear a sonic boom. This path is known as the “boom carpet.”
The sonic booms can be sometimes quite loud. For a commercial supersonic transport plane (SST), it can be as loud as 136 decibels, or 120 Pa (in units of pressure). This can break windows and even make whole buildings shake.
How pilots and passengers handle sonic boom? Pilots actually don’t hear them. They can see the pressure waves around the plane, but people on board the airplane can’t hear the sonic boom. Like the wake of a ship, the boom carpet unrolls behind the airplane.
How far can you hear a sonic boom? It states that you hear a primary sonic boom coming from the aircraft within a lateral distance of ~20nm (solid lines) as well as a secondary boom within a distance of 60-85nm (dashed lines). This secondary waves are a reflection of the upwards travelling shock waves from the aircraft at the atmosphere.