I was doing defense contracting in the 80's where I was out in Nevada during some field tests. During these tests, I heard a few sonic booms. To me they were unique in they were more like a BaBOOM. Always in pairs. One caused by the front, and one by the back of the aircraft.

I never saw the aircraft breaking the sound barrier though. (They were high). I also got buzzed by the subsonic ones down low too.