Long Range Acoustic Device
The Long Range Acoustic Device (LRAD) is an acoustic hailing device developed by LRAD Corporation to send messages and warning tones over longer distances or at higher volume than normal loudspeakers. LRAD systems are used for long range communications in a variety of applicationsincluding as a means of non-lethal, non-kinetic crowd control. LRADs have been called "sonic weapons" though they are incapable of producing any permanent injury nor are they inherently for military use.
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°- 60° beam at 2.5 kHz.The manufacturer also produces systems for public address and mass notification use that broadcast 360°.
LRAD systems are used by maritime, law enforcement, military and commercial security companies to send instructions and warnings over distance, and can be used to initiate. LRAD systems are also used to deter wildlife from airport runways, wind and solar farms, nuclear power facilities, gas and oil platforms, mining and agricultural operations, and industrial plants.
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.
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.”
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.
The New Jersey State Police used an armored vehicle mounted LRAD on crowds denied entry to a June 7, 2015 concert after they began throwing bottles and tried to rush the gates outside MetLife Stadium.
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 
- Turkey: Used by the Turkish Naval Forces
- 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.
- Romania: Used first time on 7 june 2015 by Jandarmeria Romana
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