'Sonic cannon' used to blast protesters' ears in Pittsburgh.Byline: ANI Washington, September 27 (ANI): Police in Pittsburgh, US, has showed the usage of the 'sonic cannon', which is the latest innovation in crowd control, by blasting the ears of protesters near the Group of 20 meeting of world economic leaders. City officials said it was the first time such sound blasters, sometimes called sound weapons, were used publicly. "There was an array of sound amplifiers used during the demonstration," Lavonnie Bickerstaff of the Pittsburgh Bureau of Police, told Live Science. "The Poconos police brought the long-range acoustic device with them, but I don't know Don't know (DK, DKed) "Don't know the trade." A Street expression used whenever one party lacks knowledge of a trade or receives conflicting instructions from the other party. whether it was used," he said. The long range acoustic device The long range acoustic device (LRAD) is a crowd-control and hailing device developed by American Technology Corporation. The equipment weighs 45 pounds (20 kg) and can emit sound in a 15 to 30° beam (only at high frequency) from a device 33 inches (83 cm) in (LRAD LRAD Long Range Acoustic Device (non-lethal weapon that creates a directed beam of earsplitting noise) LRAD Long-Range Alpha (Particle) Detection LRAD Licentiate of the Royal Academy of Dance ) is designed for long-range communication and "unmistakable warning," according to the American Technology Corporation  Please help [ improve this article] by expanding it.Further information might be found on the talk page or at requests for expansion. , which develops the instruments. "The LRAD basically is the ability to communicate clearly from 300 meters to 3 kilometers", said Robert Putnam of American Technology's media and investor relations Investor relations The process by which the corporation communicates with its investors. . "It's a focused output. What distinguishes it from other communications tools out there is its ability to be heard clearly and intelligibly at a distance, unlike bullhorns," he added. Its shrill warning tones can be heard at least 1,600 feet (500 meters) away and depending on the model of LRAD, it can blast a maximum sound of 145 to 151 decibels - equal to a gunshot - within a 3-foot (one meter) range, according to American Technology. But there is a volume knob, so its output can be less than max, Putnam noted. On the decibel decibel (dĕs`əbĕl', –bəl), abbr. dB, unit used to measure the loudness of sound. It is one tenth of a bel (named for A. G. Bell), but the larger unit is rarely used. scale, an increase of 10 (say, from 70 to 80) means that a sound is 10 times more intense. Normal traffic noise can reach 85 decibels. Anything over 120 decibels is liable to be noticeably painful for some individuals, and 150 decibels would hurt anyone's ears. Such sounds damage small hair cells Hair cells Sensory receptors in the inner ear that transform sound vibrations into messages that travel to the brain. Mentioned in: Cochlear Implants in the inner ear that convert sound energy into electrical signals that travel to the brain. But, Putnam said that under normal circumstances, the LRAD is not harmful. "There's no way it can hurt you unless you have the ability to stand in front of it closely for several minutes," Putnam said. The instrument's volume, along with its high-pitched tone, make for painfully loud sound frequencies that are concentrated in a narrow beam and easily direct them at a target, not unlike using a spotlight. (ANI) Copyright 2009 Asian News International The Asian News International (ANI) agency provides multimedia news to China and 50 bureaus in India. It covers virtually all of South Asia since its foundation and presently claims, on its official website, to be the leading South Asia-wide news agency. (ANI) - All Rights Reserved. Provided by Syndigate.info an Albawaba.com company |
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