Loud, annoying noises have been a "weapon" at the personal level for millennia, but recently the world's security and military forces have been using a far more potent sonic weapon known as the "long range acoustic device" or LRAD. Just under 3 feet in diameter and weighing 45 pounds, the black circular device emits an intense 15- to 30-degree-wide acoustic beam -- a high-pitched shrill tone similar to a smoke detector alarm -- that can easily cause permanent auditory damage at close range.

At 100 yards, the LRAD beam is extremely painful, but it is typically used at ranges of 300 to 500 yards as a warning or deterrent weapon. LRAD's are used by the U.S. Navy and Coast Guard to warn off approaching vessels, and the weapon has been tested in Iraq in various capacities.