Sonic weapon

Sonic and ultrasonic weapons are directed energy devices that use sound, at frequencies across and beyond the range of human hearing, to injure, incapacitate or disperse people, working through a focused beam or wide area field of sound. At high power, sound can damage hearing and cause severe pain or disorientation, while lower intensities can cause nausea or general discomfort, and some devices use ultrasonic frequencies that are uncomfortable mainly to younger listeners. The Long Range Acoustic Device produces a narrow thirty degree cone of audible sound and was used by the cruise ship Seabourn Spirit against pirates in 2005 as well as in crowd control, while the so called Mosquito device uses very high frequencies, around 19 to 20 kilohertz, mainly to disperse groups of teenagers. Sound cannons have since been deployed by police at protests including the 2009 G20 summit in Pittsburgh and the 2014 unrest in Ferguson, and sonic weapons were an early suspected cause of the Havana syndrome incidents at United States embassies from 2016 to 2017, though later investigation pointed instead toward microwave energy or psychological factors.