As a kid I can remember holidaying on the Isle of Wight (1957, I think) and hearing the sonic booms made by experimental flights over the Solent. No-one made much of it at the time.
It was a sharp double bang, almost like two doors being slammed a fraction of a second apart. Only later, when Concorde was being tested, did the problem of ground damage become a talking point.
Technically, there is no reason not to exceed Mach 1 over an airshow but I would expect the NIMBY neighbours to complain loud and long (and sue if there was as much as a broken wineglass...) so I doubt it will ever happen. Pity.
VnV...