You can call it Sound Burst propulsion.
Think of modulating a continuous stream of a jet output. That is, switch On and Off of a stream of water, air ....and sound. This produces more thrust.
The water Ramjet is one example of this simple mechanism. Another is the childhood PhutPhut candle driven steam boat that goes PhutPhutPhut.......audibly!!!
The exhaust system of internal combustion engines are Acoustic chambers and are designed to increase compression using air as a "wall" and create 'back compression' !! You see this all the time in Racing, especially the MoBikes which make a lot of sound.