It's possible this could be fought by building a fairly large corner-cube retroreflector and aiming it at the source of the sound. While that might not be precise, it would send a lot of sound back to the area around the emitter. Jim Bell
https://www.thedailybeast.com/how-the-lrad-went-from-a-pirate-deterrent-to-a-police-crowd-control-tool
