Long Range Acoustic Device
The Long Range Acoustic Device (LRAD), also known as a sound cannon, 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 145.1 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, have an interference pattern in the nearfield which produces peaks 6 dB higher than the output pressure and nulls where the pressure is essentially zero. The larger the speaker, and the higher the frequency, the longer the effective nearfield. The nearfield for this device is approximately 8m.
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". 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.
Israel's Ministry of Defense ordered LRADs 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.
LRAD was present, but not used because of current legal regulations during protests in Poland, including Million Marijuana March 2011 and Marsz Niepodległości (National Independence Day March) 2011 and 2012. Lacking a way to utilize the LRADs purchased to their full potential sparked an investigation suspecting corruption behind their acquisition. National Police Headquarters spokesman Mariusz Sokolowski defended the purchase of LRAD. He also stressed that the police decided to make this investment because, "We needed good sound reinforcement equipment. With numerous demonstrations and gatherings, police need a public address system that allows you to reach thousands of people."
LRAD was deployed during a NATO march on May 20, 2012 in Chicago, Illinois at Michigan Ave. & Cermack.
The Salisbury, MD Police Department acquired an LRAD in October 2013 with proceeds from their speed cameras.
13, 18 August 2014 St. Louis County police used LRAD against protestors demonstrating the police shooting of Michael Brown in Ferguson, Missouri. Reporter Mike Tobin commented while broadcasting from Ferguson, MO on 18 August, “It doesn't have the effect of crippling people. It's just loud, it's annoying, it lets you know something big and official is coming and that’s what’s happening now. They can also use it as a loudspeaker to tell people to get out of the way.” Later Amnesty International criticized the use of LRAD against protesters and members of their delegation at Ferguson, who “reported feeling nauseous from the noise”, and that “LRADs can pose a serious health risks which range from temporary pain, loss of balance and eardrum rupture, to permanent hearing damage.”
On December 5th, 2014, the NYPD used a Long Range Acoustic Device (LRAD) to disperse about 100 protesters who were on the streets protesting the police killing of Eric Garner in Midtown Manhattan.
The NYPD used a Long Range Acoustic Device during the Baltimore solidarity rally in Union Square on April 29, 2015. An NYPD pickup truck equipped with an LRAD parked near protesters and began broadcasting a looped warning message about staying off the streets and not blocking the sidewalks.
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 August 2013, Carl "Rocky" Mason, one of the three members of the security attachment aboard the Biscaglia during the incident, stated that an LRAD was aboard, but that he and the security attachment only had time to open the water cannons before gunfire and an RPG round forced them to abandon ship. No attempt was made to use the LRAD device during the incident.
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. 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.
- Azerbaijan: Azerbaijan police 
- Canada: Multiple police departments
- Hong Kong: Police Tactical Unit and Police Negotiation Cadre (PNC) of the Hong Kong Police Force
- India: Delhi Police
- Israel: Ministry of Defense
- Poland: Polish Police
- Singapore: Used by the Singapore Armed Forces
- Spain: Reported use by Catalan Police 
- United Kingdom: Ministry of Defence
- United States: Multiple police departments and US Army
- Vietnam: Being used on-board DN-2000-class ships of the Vietnam Coast Guard's fleet.
- Corbett, Peter. A Modern Plague of Pirates. p. 65. ISBN 0-9562107-0-8.
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- Blackstock, David T. 2000. Fundamentals of Physical Acoustics, p.456, John Wiley and Sons.
- "The future of crowd control". The Economist 373 (8404–8406): 54. December 2, 2004.
- http://thedailyshow.cc.com/videos/oj7p5c/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
- 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.
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- (http://view.vzaar.com/2007295/video (2'45" - 3'10"))
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- Sonic Device used to repel pirates
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- 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
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- "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.
- This Pain-Inducing Acoustic Device Used to Control Crowds in Azerbaijan Might Be U.S.-Made, The Atlantic, March 14, 2013
- [=http://www.eldiario.es/politica/Centenares-personas-recorren-Madrid-Gamonal_0_219078935.html El Diario : News : Los mossos utilizan un cañón de sonido para dispersar a los manifestantes en Barcelona]
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