"The NASA Shaped Sonic Boom Demonstration, also known as the Shaped Sonic Boom Experiment, was a two-year program that used a Northrop F-5E with a modified fuselage to demonstrate that the aircraft's shock wave, and accompanying sonic boom, can be shaped, and thereby reduced. The program was a joint effort between NASA's Langley Research Center, Dryden Flight Research Center at Edwards Air Force Base, California and Northrop Grumman.

The program became, at that time (2003 according to Supersonic transport), the most extensive study on the sonic boom. After measuring the 1,300 recordings, some taken inside the shock wave by a chase plane, the SSBD demonstrated a reduction in boom by about one-third."


https://en.wikipedia.org/wiki/Shaped..._Demonstration