US Patent 11931199 Nozzles for amplifying and suppression of sound

The invention discloses a novel passive sound transformer, either a sound-booster or a sound-silencer, embodied as an acoustic waveguide, a specific shape of which provides for either amplifying the intensity of acoustic waves at the expense of both the heat energy and the concomitant turbulence of moving fluid wherein the amplified intensity of the acoustic waves is manifested as sound loudness boosting or, contrarywise, transforming the wave power of elastic waves into the heat of the ambient fluid.