A public records search conducted by East County Magazine has confirmed that the device is an LRAD 500-x manufactured by San Diego-based American Technology Corporation (ATC). Capable of use as an effective loudspeaker, the LRAD also has the ability to emit a deafening tone aimed at incapacitating and dispersing a crowd without use of lethal force.
LRADs were developed by ATC at the request of the U.S. Navy after the attack on the U.S.S. Cole as a means of dissuading hostile invaders. ATC founder Elwood "Woody" Norris is a pioneer in sound technology who has also been instrumental in development of ultra-sound and ground penetrating radar.
Cruise ship Captain Michael Groves successfully repelled pirates off the Somali coast using non-lethal weapons including an LRAD. Groves has since filed suit against Carnival Cruise Line, claiming he suffered permanent hearing loss as a result, the BBC has reported. Navy News describes the LRAD as "louder than a jet engine" and helpfully explains that it overwhelms its targets with "sound so loud they hear it inside their heads."