How to protect yourself from LRAD, the “sound cannon” police are using at protests
LRAD can be used to generate extremely loud high-frequency sounds specifically intended for the dispersal of crowds, which can also cause pain, disorientation, and injury to those exposed to them, Pitchfork explains and advises how to defend yourself from it. Use earplugs or safety ear muffs with the highest dB-reduction rating you can find; look for places to shelter - sound waves deflect off dense and rigid surfaces, so brick and concrete walls are a good bet; in case of no earplugs and shelter, go left or right if the LRAD is in front of you, rather than just backing up - the sound is a beam and walking perpendicularly to the direction of that beam helps.