My understanding of the sonic boom is that it is caused when shockwaves being emitted from an object travelling at Mach 1 or above compress and superimpose on each other because they cannot move out of the way fast enough causing an explosive release of sound energy. This was an issue throughout the gestation period of Concorde effectively halving its potential route network since no government would allow routine supersonic flight over populated areas. For a future SST are there any ways in which the effects of the boom could be curtailed somewhat?