Quote:Unlike a conventional speaker, which vibrates a diaphragm to amplify sound, the LRAD uses piezoelectric transducers to concentrate and direct acoustic energy. Inner and outer transducers bend and vibrate to create sound waves that are not completely in phase with each other. This creates sound waves that cancel out those in the outermost edges of the beam. It also creates a sound that is "flatter" than usual, with minimal dispersion as it propagates. The LRAD's sound waves also interact with the air in ways that create additional frequencies within the wave, thus amplifying the sound and pitch. This allows for voice commands—pre-recorded and played off its built-in MP3 player, or spoken by an officer into a microphone—at a volume meant to be intelligible 600 meters away.

The machine's "alert mode" is its deterrent feature. Imagine pressing your head against the hood of a car while its alarm is going off. Permanent hearing loss begins with a sustained sound that's louder than 90 dB SPL—for example, a subway train 200 feet away—but you won't start to feel immediate pain until 120 decibels, about the loudness of a shotgun blast. At 160 dB—a little less loud than a rocket launch—your eardrum will burst.
The tones of the LRAD can reach as high as 152 decibels—20 to 30 dB louder than a bullhorn—which can easily cause permanent hearing damage. It's a siren that makes the adjective "earsplitting" much less of a metaphor.

Quote:"In person, at first I thought it was just a high pitched really loud car alarm," Anika Edrei, a photojournalist who was documenting the Eric Garner protests, told me. In the early morning hours on December 5th, Edrei said she was just ten meters away from an LRAD device when the NYPD switched on its alarm function. "It was really loud—I could hear it through my fingers."

Edrei said that protesters were already dispersing down the block, on 58th Street, when something smashed against the ground. "The police took that as a violent threat," she said. That's when the siren went off.

Afterwards, "for the first week, I had a migraine, and just a lot of facial pressure," she said. "Since the LRAD incident, I've been pretty freaked out about going back," she added. "I'm worried about what damage it caused and it could cause if I went out there again."

"It feels like your eardrums are beating out of your head," photojournalist Shay Horse, who was also nearby, told VICE News. "It makes the side of your body that you've been hit on feel numb and that your sinuses are inflamed. I felt like I had blood coming out of my orifices. I heard the ringing for about a week."

Quote:In a letter to the NYPD last week, lawyers from the National Lawyers Guild contended that the NYPD had used their LRADs last week "at unsafe distances and unreasonably high volumes."


Elena Cohen, a co-author of the letter to the NYPD and the president of the New York chapter of the National Lawyers Guild, expressed concerned about the distance issue, in an email. "We're still determining at what distance the police were from the protesters when the LRAD was used. As you can see from the videos below, it seems as though they are relatively close." In addition to the video above, she attached these videos:

Quote:The LRAD first appeared in the streets of New York during the protests surrounding the Republican National Convention, after the NYPD purchased two of them for $35,000 each. (I was reporting on the convention, and saw it—a black circular thing the size and shape of a giant birthday cake—mounted on a police truck.) LRAD devices would also make appearances during the Occupy Wall Street protests. But until last week, there was no known use of the LRAD's deterrent siren in New York.

The first high-profile use of an LRAD in the U.S. took place in the streets of Pittsburgh in 2009, during the G20 Summit. Karen Piper, an English professor at the University of Missouri, who was researching protests around the International Monetary Fund and the World Bank, was 100 feet away when police used the LRAD siren, "without warning, causing a continuous piercing sound to be emitted for a number of minutes." She sued the city of Pittsburgh, claiming the LRAD gave her nausea and headaches, and made fluid leak out of her ear.

"Contrary to some reports," says the LRAD Corporation's website," LRAD does not generate the ultra low frequency tones that are needed to cause nausea and disorientation." But it also notes that “LRAD broadcasts have been optimized to the 1 – 5 kHz range where human hearing is most sensitive.” Pittsburgh ultimately settled the suit for $72,000 and agreed to develop a policy for the safe use of an LRAD .

Quote:A number of private security contractors own them, and one has appeared at London's O2 arena, presumably for crowd control. Now LRAD's are designed to operate remotely—the new one is "IP addressable"—and they're now being put on drone boats. In 2014, the LRAD Corporation received a number of million-dollar orders from un-named Asian and Middle Eastern customers.

Quote:"The introduction of any new weapon into police arsenals requires a process of objective scientific research into the short-term and long-term physical effects of the weapon’s use, consultation with the public who are the potential targets of such weapons, and policy debates. Reliance on research by the manufacturer is insufficient. . . . Simply put, new weapons such as the LRAD should not be employed without prior independent assessment and study."

Quote:"When the police use it, it’s not as if they’re just targeting one person," Gideon Oliver, a New York lawyer, told Gothamist. "It’s indiscriminate like teargas.” Oliver was one of the lawyers who authored the recent letter of complaint to the NYPD's commissioner asking for more details about the program. An earlier Freedom of Information Law request he filed in 2012 contained no rules on the use of LRADs. Another known FOIA request sent to the Boston Police Dept. in 2012 by Muckrock's Michael Morisy received no effective response.

(10-28-2016, 06:48 PM)Ninurta Wrote: Rather than researching their effects, I think it would be more prudent to research ways to defeat them and nullify them, which would curtail their use. Historically, anything can be weaponized, and anything weaponized will eventually be used by a corrupt, abusive government against it's citizenry.