creating fusion with sound waves (or shock waves, which is essentially what sound becomes at high enough energy) is one of the crazier ideas I've heard..
Sonofusion [0] was a neat idea, and some of the relevant experiments (at least the cavitation part) can be done on a bench top with a hobbyist level budget. Last I checked, the research had been somewhat tarnished by academic fraud. The physics of jet formation during bubble collapse near a solid boundary remains fascinating [1].
Well yeah, if your shock waves for fusion are created by nuclear fission chain reaction that technology has been quite ready and mature since the 1960s.
