Long Range Acoustic Device
The Long Range Acoustic Device (LRAD) is an acoustic hailing device and sonic weapon developed by LRAD Corporation to send messages, warnings, and harmful, pain inducing tones over longer distances than normal loudspeakers. LRAD systems have been used to counter piracy, as non-lethal crowd control weapons, and as communication devices.
According to the manufacturer's specifications, the systems weigh from 15 to 320 pounds (6.8 to 150 kg) and can emit sound in a 30° beam at 2.5 kHz.
LRAD systems are used by maritime, law enforcement, military and commercial security companies to send instructions and warnings over distances, and to force compliance. LRAD is also used to deter wildlife from airport runways, wind and solar farms, nuclear power facilities, mining and agricultural operations and other industrial facilities.
The parameter "ka", which is the wave number multiplied by the speaker radius, is often used to characterize sound source directivity. For this source, ka=19 at 2.5 kHz, and according to the LRAD data sheet, the beam angle of about 30 degrees total is precisely what is predicted for a regular loudspeaker.
Small spherical "point-source" acoustic devices follow the known inverse square law, which predicts the loss of 6 dB per doubling of distance from the source, solely due to geometric spreading. Large speakers (or large arrays), such as these mentioned above or those commonly used in concert halls, etc., produce less attenuation with distance in the nearfield, typically 3–4 dB per doubling of distance from the source. The larger the speaker, and the higher the frequency, the longer the effective nearfield. Devices like this generally have nearfields of only a few meters. However, sound radiated from an infinite plane source is not attenuated due to geometric spreading, but is affected by other sound propagation effects.
LRAD Corporation was formerly named American Technology Corporation. In 2004, Carl Gruenler, a former vice president of military and government operations for American Technology Corporation said that being within 100 metres (330 ft) of the LRAD is extremely painful, and that it was designed for use in short bursts at 300 metres (980 ft), to give targeted people a headache. He said that "you definitely don't want to be" within 100 m; and, that the device will cause permanent auditory damage. LRAD officials deny such common uses, claiming that the device is not a weapon, rather it is a "directed-sound communications system", and that it can damage hearing at 15 metres (49 ft). After LRAD devices were used during the 2009 G-20 Pittsburgh summit, American comedian Jon Stewart lampooned the supposed harmful effect of LRAD’s deterrent tone on The Daily Show with Jon Stewart by putting his fingers in his ears.
Against protesters 
In 2009, the government of Honduras used LRAD on at least two occasions, on September 22 and 25, on those seeking refuge in the Brazilian embassy. In addition to embassy staff, these included the deposed president of Honduras, Manuel Zelaya, his family, and some supporters and journalists. In a photo, there are two LRAD models, the LRAD 1000 (or 1000X or 1000Xi) and the LRAD 100X. Israel was accused of supplying these devices,
The LRAD was used for the first time in the United States in Pittsburgh during the time of the G20 summit on September 24–25th, 2009. Pittsburgh police again utilized LRAD as a precautionary measure to prevent unruly crowds from getting out of control following the 2011 Super Bowl.
Israel's Ministry of Defense ordered LRAD units in June 2011.
LRAD was present, but not used, when the New York City Police department cleared Occupy Wall Street protestors from Zuccotti Park on the morning of 15 November 2011. Two days later it was reportedly used briefly against Occupy Wall Street protesters.
The Delhi Police are purchasing 5 LRADs for crowd control.
The LRAD was deployed during a NATO march on May 20, 2012 in Chicago, Illinois at Michigan Ave. & Cermack.
Against pirates 
On November 5, 2005, the luxury cruise ship Seabourn Spirit employed an LRAD while repelling pirates who attacked the vessel with rocket-propelled grenades about 115 km off the coast of Somalia. The effectiveness of this device during the attack is not completely clear, but the pirates did not succeed in boarding the vessel and eventually fled.
The Liberian vessel MV Biscaglia was attacked on November 28, 2008. The security detachment aboard Biscaglia claimed to have used an LRAD device in an effort to repel attackers armed with assault rifles and rocket-propelled grenades. Following a one-sided shootout, the ship was seized and the unarmed security contractors abandoned ship leaving the ship and crew to the pirates. The incident caused the usefulness of LRADs to be called into question by Lloyd's List. In January 2011, the Spirit of Adventure, a cruise ship sailing through the Indian Ocean, deployed a LRAD system as part of its defensive measures when being pursued by pirates.
London Olympics 2012 
In February 2009, the Japanese whaling fleet operating in Antarctic waters near Australia installed LRADs on their vessels. The device was used against activists of the Sea Shepherd Conservation Society after they harassed the factory ship. The Japanese fleet later escalated the use of LRAD, deploying it against a Sea Shepherd helicopter carrying a camera crew. Sea Shepherd noted that they had an LRAD of their own, but as of early 2010, had not put it into use other than to play a recording of "Ride of the Valkyries" in the manner of attacking U.S. Army helicopters depicted in the 1979 film Apocalypse Now.
See also 
- Corbett, Peter. A Modern Plague of Pirates. p. 65. ISBN 0-9562107-0-8.
- Beranek, Leo L. 1986. Acoustics, p.132, American Institute of Physics.
- "The future of crowd control". The Economist 373 (8404–8406): 54. December 2, 2004.
- Sloan, Gene (January 17, 2011). "Cruise ship blasted pirates with sonic wave". USA Today. Retrieved July 17, 2011.
- http://www.thedailyshow.com/watch/mon-september-28-2009/pittsburgh-irates The Daily Show with Jon Stewart (2'32" - 3'15")
- ABC News. Technology & Science. August 25, 2004. Amanda Onion. RNC to Feature Unusual Forms of Sound: Unusual Forms of Sound to Emanate From RNC
- RussiaToday : News : Georgian police accused of brutality
-  Machetera, "Micheletti’s newest U.S./Israeli toy", 25 September 2009
- “Cañón sónico” para revoltosos
- Protesters Are Met by Tear Gas at G-20 Conference - NYTimes.com
- LRAD used in residential neighborhood in Pittsburgh, Pa during the G20 summit
- LRAD Corporation Announces Opening LRAD® Order from Israel's Ministry of Defense 
- Martin, Adam (25 October 2011). "Occupy Oakland's Tent City Is Gone". The Atlantic Wire. Retrieved 26 October 2011.
- "LRAD vs OWS: Sound cannons rolled out for Zuccotti park raid". Russia Today. 15 November 2011. Retrieved 18 April 2012.
-  Russia Today, NYPD blast LRAD sound cannons at OWS, Published: 17 November 2011,Edited: 18 November 2011
- Ship Blasted Pirates With Sonic Weapon
- "I beat pirates with a hose and sonic cannon". BBC News. May 17, 2007. Retrieved May 11, 2010.
- Sonic Device used to repel pirates
- David Osler, (2 December 2008). "Sonic solution may not be a sound investment", Lloyd's List. London: Informa. Retrieved 13 April 2011.
- News, BBC (12 May 2012). "'Sonic weapon' deployed in London during Olympics". BBC News. Retrieved 11 May 2012.
- Darby, Andrew (February 6, 2009). "Whalers attack activists at sea". The Age (Melbourne).
- Video - Sea Shepherd
- Sea Shepherd Battles Japanese Whalers in the Ross Sea - Sundance Channel, 7 February 2009
- "Street Fight on the High Seas". The New Yorker. 2010-01-12. Retrieved 2010-01-16.
- "Ride Of The Valkyries: Japanese Whalers Claim Sea Shepherd Harasses The Nisshin Maru With Classical Music". Underwatertimes.com (Tokyo). February 9, 2010. Retrieved January 1, 2011.
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