Sonic weapon

Sonic and ultrasonic weapons (USW) are weapons of various types that use sound to injure, incapacitate, or kill an opponent. Some sonic weapons are currently in limited use or in research and development by military and police forces. Others exist only in the realm of science fiction. Some of these weapons have been described as sonic bullets, sonic grenades, sonic mines, or sonic cannons. Some make a focused beam of sound or ultrasound; some make an area field of sound. Although many real sonic and ultrasonic weapons are described as "non-lethal", they can still kill under certain conditions.

Designed to emit sound as an irritant

Extremely high-power sound waves can break the eardrums of a target and cause severe pain or disorientation. This is usually sufficient to incapacitate a person. At higher energy levels, a subsonic shock wave is theoretically powerful enough to do damage (see Earthquake).^{[citation needed]} The possible effects have been the subject of much speculation. The EMF Dosimetry Hand Book will provide further results of the bio-effects and expectations of these weapons. [4] Less powerful sound waves can cause humans to experience nausea or discomfort. The use of these frequencies to incapacitate persons has occurred both in counter-terrorist and crowd control settings.

The possibility of a device that produces frequency that causes vibration of the eyeballs — and therefore distortion of vision — was apparently confirmed by the work of engineer Vic Tandy^[1][2] while attempting to demystify a “haunting” in his laboratory in Coventry. This “spook” was characterised by a feeling of unease and vague glimpses of a grey apparition. Some detective work implicated a newly installed extractor fan that, Tandy found, was generating infrasound of 18.9 Hz, 0.3 Hz, and 9 Hz.

In 2005 CNN reported that the crew of the cruise ship Seabourn Spirit used a long range acoustic device (LRAD) to deter pirates who chased and attacked the ship[5]. Its actual efficacy, however, has not been established.

The BBC reported in Oct 2006 on a 'mobile' sonic device which is being used in Grimsby, Hull and Lancashire and is designed to deter troublesome teenagers from lingering around shops in target areas. The device works by emitting an ultra-high frequency blast (around 19-20 kHz) that teenagers or people under approximately 20 are susceptible to and find uncomfortable. Age-related hearing loss apparently prevents the ultra-high pitch sound from causing a nuisance to those in their late twenties and above, though this is wholly dependent on a young person's exposure to high sound pressure levels.

During the G20 event in Pittsburgh, police used a sound cannon against protestors.^[3]

Demonstrated infrasonic weapon

The U.S. DOD has demonstrated phased arrays of infrasonic emitters. The weapon usually consists of a device that generates sound at about 7 Hz. The output from the device is routed (by pipes) to an array of open emitters. At this frequency, armor and concrete walls and other common building materials allow sound waves to pass through, providing little defense.^[4]