3 MAD devices, rear

Three M.A.D. (Magnetic Acoustic Devices) from HPV Technologies (www.getmad.us), during a demo for military, law enforcement, and government tech experts from the US and abroad, at Edwards Air Force Base in Palmdale (Sep 1, 2005). The devices are capable of broadcasting a highly focused, "laser-like" beam of sound in such a way that it is intelligible for a mile or more. The event was organized by the LA Sherriff's Department, which is considering using the devices for civil unrest and disaster communications. A donated device will be shipped to authorities in Mississippi for those purposes this week.