Bill Nelson actually said...
It will fly supersonic but its design is such a radical design, that instead of pushing the bow wave going through the atmosphere, as you go from subsonic to supersonic, which causes that audible sound that goes 'boom, boom,' it will, because of the design as you go supersonic, it will be a muffled roar.
Context
Nelson explains the unique design of the X-59 that minimizes sound during supersonic flight.
05/16/2023