Long range acoustic device
Encyclopedia
LRAD Corporation
LRAD Corporation is based in San Diego, California. Its Long Range Acoustic Device product is used for long range communications, crowd control and distant hailing. The company was previously named American Technology Corporation...
to send messages, warnings, and harmful, pain inducing tones over longer distances than normal loudspeaker
Loudspeaker
A loudspeaker is an electroacoustic transducer that produces sound in response to an electrical audio signal input. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful...
s.
According to the manufacturer's specifications, the systems weigh from 15 to 320 lb (6.8 to 145.1 ) 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.
Function
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
Near and far field
The near field and far field and the transition zone are regions of the electromagnetic radiation field that emanates from a transmitting antenna, or as a result of radiation scattering off an object...
, 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. Carl Gruenler, former vice president of military and government operations for American Technology Corporation said that being within 100 metres (328.1 ft) of the LRAD is extremely painful, and that it was designed for use in short bursts at 300 metres (984.3 ft), to give targeted people a headache. He said that "you definitely don't want to be" within 100 m; 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 (49.2 ft). American comedian Jon Stewart
Jon Stewart
Jon Stewart is an American political satirist, writer, television host, actor, media critic and stand-up comedian...
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
The LRAD device was on hand at protests2004 Republican National Convention protest activity
2004 Republican National Convention protest activity includes the broad range of marches, rallies, performances, demonstrations, exhibits, and acts of civil disobedience in New York City to protest the 2004 Republican National Convention and the nomination of President George W. Bush for the 2004 U.S...
of the 2004 Republican National Convention
2004 Republican National Convention
The 2004 Republican National Convention, the presidential nominating convention of the Republican Party of the United States, took place from August 30 to September 2, 2004 at Madison Square Garden in New York City, New York...
in New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
but not used; it was extensively used against opposition protesters in Tbilisi
Tbilisi
Tbilisi is the capital and the largest city of Georgia, lying on the banks of the Mt'k'vari River. The name is derived from an early Georgian form T'pilisi and it was officially known as Tiflis until 1936...
, Georgia
Georgia (country)
Georgia is a sovereign state in the Caucasus region of Eurasia. Located at the crossroads of Western Asia and Eastern Europe, it is bounded to the west by the Black Sea, to the north by Russia, to the southwest by Turkey, to the south by Armenia, and to the southeast by Azerbaijan. The capital of...
, in November 2007.
The magazine Foreign Policy has revealed that LRADs have been sold to the government of the People's Republic of China
People's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...
. American companies have been banned from selling arms to China since the Tiananmen Square protests of 1989
Tiananmen Square protests of 1989
The Tiananmen Square protests of 1989, also known as the June Fourth Incident in Chinese , were a series of demonstrations in and near Tiananmen Square in Beijing in the People's Republic of China beginning on 15 April 1989...
.
Local residents of Dusit in Bangkok
Bangkok
Bangkok is the capital and largest urban area city in Thailand. It is known in Thai as Krung Thep Maha Nakhon or simply Krung Thep , meaning "city of angels." The full name of Bangkok is Krung Thep Mahanakhon Amon Rattanakosin Mahintharayutthaya Mahadilok Phop Noppharat Ratchathani Burirom...
witnessed it in use during protests of Triumph
Triumph International
Triumph International is an international underwear manufacturer. Founded in Heubach, Württemberg, Germany 1886 by the two families Spiesshofer & Braun. The first foreign subsidiary was established in Zurzach, Switzerland which...
factory employees against dismissals on August 28, 2009. The LRAD was used for the first time in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
in Pittsburgh during the time of the G20 summit
2009 G-20 Pittsburgh summit
The 2009 G-20 Pittsburgh Summit was the third meeting of the G-20 heads of state in discussion of financial markets and the world economy.The G-20 is the premier forum for discussing, planning and monitoring international economiccooperation....
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. LRAD systems were also purchased by Toronto Police for the 2010 G20 summit
2010 G-20 Toronto summit
The 2010 G-20 Toronto summit was the fourth meeting of the G-20 heads of government, in discussion of the global financial system and the world economy, which took place at the Metro Toronto Convention Centre in Toronto, Ontario, Canada, during June 26–27, 2010...
.
In 2009, the government of Honduras
Honduras
Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...
used it on at least two occasions, on September 22 and 25, to communicate to those seeking refuge in the Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
ian embassy. In addition to embassy staff, these included the deposed president of Honduras, Manuel Zelaya
Manuel Zelaya
José Manuel Zelaya Rosales is a politician who was President of Honduras from January 27, 2006 until June 28, 2009. The eldest son of a wealthy businessman, he inherited his father's nickname "Mel," and, before entering politics, was involved in his family's logging and timber businesses.Elected...
, his family, and some supporters and journalists.
LRAD was also used against college students in the city of Macomb, Illinois at the Wheeler Block Party at Western Illinois University ("WIU") on May 1, 2011.http://www.shtfplan.com/headline-news/police-make-mass-arrests-use-tear-gas-sound-weapons-at-college-block-party_05062011
LRAD was reportedly used by the Oakland Police Department during the clearance of the Occupy Oakland
Occupy Oakland
Occupy Oakland is a series of demonstrations including the occupation of public spaces that began in downtown Oakland at Frank H. Ogawa Plaza in front of Oakland City Hall in Oakland, California on October 10, 2011. It is allied with the Occupy Wall Street movement in New York City and is one of...
encampment on the morning of 25 October 2011.
The Polish Police acquired LRAD units in December 2010 and used them to communicate with protesters during the 11 November 2011
Polish Independence Day
National Independence Day is a public holiday in Poland celebrated every year on 11 November to commemorate the anniversary of Poland's assumption of independent statehood in 1918 after 123 years of partition by Russia, Prussia and Austria....
riots in Warsaw
Warsaw
Warsaw is the capital and largest city of Poland. It is located on the Vistula River, roughly from the Baltic Sea and from the Carpathian Mountains. Its population in 2010 was estimated at 1,716,855 residents with a greater metropolitan area of 2,631,902 residents, making Warsaw the 10th most...
.
LRAD use was present, but not used, as the New York City Police department cleared protestors during the Occupy Wall Street protests in Zuccotti Park on the morning of 15 November 2011.http://rt.com/news/lrad-acoustic-weapon-zuccotti-383/
Against pirates
Somalia
Somalia , officially the Somali Republic and formerly known as the Somali Democratic Republic under Socialist rule, is a country located in the Horn of Africa. Since the outbreak of the Somali Civil War in 1991 there has been no central government control over most of the country's territory...
. 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 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 rifle
Assault rifle
An assault rifle is a selective fire rifle that uses an intermediate cartridge and a detachable magazine. Assault rifles are the standard infantry weapons in most modern armies...
s 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
Lloyd's List
Lloyd's List is one of the world's oldest continuously-running journals, having provided weekly shipping news in London as early as 1734. Now published daily, a recent issue was numbered 59,200...
, 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.
Whaling
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 shipFactory ship
A factory ship, also known as a fish processing vessel, is a large ocean-going vessel with extensive on-board facilities for processing and freezing caught fish...
. 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
Ride of the Valkyries
The Ride of the Valkyries is the popular term for the beginning of Act III of Die Walküre, the second of the four operas by Richard Wagner that comprise Der Ring des Nibelungen. The main theme of the Ride, the leitmotif labelled Walkürenritt, was first written down by the composer on 23 July 1851...
" in the manner of attacking U.S. Army helicopters depicted in the 1979 film Apocalypse Now
Apocalypse Now
Apocalypse Now is a 1979 American war film set during the Vietnam War, produced and directed by Francis Ford Coppola. The central character is US Army special operations officer Captain Benjamin L. Willard , of MACV-SOG, an assassin sent to kill the renegade and presumed insane Special Forces...
.
External links
- LRAD Corporation Website
- LRAD Defense Updates' Summary
- Howstuffworks.com "How LRAD Works"
- Defense Update Non-lethal Directed Energy Weapons