An LRAD is a long-range acoustic device, a powerful portable speaker designed to scare people away with sound, and it's becoming increasingly popular among police departments. It is often described by critics as a sound cannon, offering a user “the ability to issue clear, authoritative verbal commands, followed with powerful deterrent tones.”
One popular device, the LRAD-100X, was used in Ferguson, and on two days last week, it was used to warn off demonstrators in New York City protesting the death of Eric Garner. According to its manufacturer, the LRAD offers police “near instantaneous escalation across the force protection spectrum” to “shape the behavior of potential threats.”
What would that sound like?
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.
During protests last week in midtown Manhattan, an LRAD siren sent people running. Image: Moth Dust
I'm worried about what damage it has caused and it could cause if I went out there again.
What It Feels Like
"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."
The NYPD also used the siren function the night before. A spokesman for the Police Department told the Times that the device had only been used to advise people of illegal conduct, and that officers are trained to control intensity of sound, duration and distance. “On December 4th all of these factors were controlled at levels that are not considered dangerous or harmful,” the spokesman said.
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:
"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 .
But as with the other military tech hand-me-downs landing at police stations across the country— grenade launchers, camouflage, armored personnel carriers, scoped rifles, Stingrays— what constitutes "safe use" of an LRAD is unclear. And there is little evidence that other police departments or anyone else are practicing safety with LRADs.
A chart of decibel levels, including those made by an LRAD device. Image: Security Pro USA
The "Potential Danger Area"
LRAD outside the O2 Arena, I guess it— Scumbly Blythe (@piombo) November 11, 2012
There are less tangible concerns too. A very loud loudspeaker or a "sound cannon" may prevent violence and obviate the use of more dangerous weapons like batons or guns. But, critics point out, it can easily fudge the line between keeping the peace and deterring public assembly. In the hands of a disorder control unit, an LRAD, with its cone of sound blasting a crowd of people, instantly, easily casts the idea of citizens gathering in public for political reasons as some kind of threat to security.
"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.
Oliver's 2012 request to the NYPD did turn up one interesting document: a 2010 internal report on an LRAD test conducted that year. (According to the report, the results of the 2004 test are "unavailable.")
From an NYPD report discovered in a 2012 FOIL request. Image: Scribd
In its 2012 study, the NYPD did not test for decibels closer than 320 feet, in a zone the report calls the 'potential danger area.'
The 2010 test was conducted in an empty parking lot on a frigid day in January, 2010, because it was surmised that the extreme cold would keep people inside. The tests measured decibels within the LRAD's sound cone from various distances. At 800 feet away, the device was 68 decibels loud, quieter than a telephone dial tone (80 dB), according to the report. At 320 feet, it was 102 dB, about as loud as a motorcycle. The officers did not apparently test for decibels closer than that, in a zone the report calls the "potential danger area."
The videos that emerged from protests in recent weeks in New York appear to show the LRAD being used at closer distances than that, and for longer bursts than suggested by the manufacturer.
An NYPD LRAD during the Republican National Convention in 2004. Image: Mike Hudack / Flickr
A diagram of the sound pressure generated by an LRAD device. Image: Security Pro USA
In the warning mode the LRAD produces sound pressure levels which are dangerous to hearing if unprotected target subjects are exposed longer than certain durations: a few seconds to 50 m distance, 1.5 minutes at 100 m. Below about 5 m, any exposure can produce permanent hearing damage.
A Toronto police department report urged against use of the LRAD's maximum volume closer than 200 m, and added, " it would be good practice not to operate the devices where bystanders are located within 10 meters of the device."
Law enforcement have defended the lead as an easy way to modify criminal behavior without using bullets or batons. “Regardless of how it has been described by the media," Maj. Joe Schrantz wrote in Army Lawyer , "the LRAD is not a weapon if it is used for its intended purpose. Instead, it is a lawful communication tool for use in complex operational environments,” where it can save lives.
Suzanne Cusick, a New York University music professor who researches acoustical violence in war, told Brian Anderson recently that there is no common international convention over the use of sound weapons, though various human rights organizations are pushing for one. The U.S. Occupational Safety and Health Administration offers guidelines, but, says Cusick, more specificity is needed. "Decibels need to be correlated with the amount of time a person is exposed to the sound at a particular decibel level," as well as the distance from the sound source.
Some places, the sound weapon is an LRAD; in others it may be just a giant boombox. In Camp Romeo, a punishment area within Guantanamo, it came from special conical speakers rolled in front of a prisoner's cell. Black Sabbath was weaponized to try to get Manuel Noriega out of the Vatican Embassy and Christmas carols and Tibetan chants were used on the Branch Davidians in Waco. At the secret U.S. "Salt Pit" in Afghanistan, it was a near-continuous white noise.
The use of sound as a weapon, which may have originated under the Third Reich or the CIA—or as a deterrent, in the terminology of those who keep the peace—raises interesting new questions. How loud and how long and how close should these sounds be to the human ear? Who else, besides the military and the police, will make use of them, and to what ends? Does the Dept. of Defense owe the industrial band Skinny Puppy royalties for the use of its music with Guantanamo captives? What kind of collateral damage will be acceptable, the age-old question of proportionality, and—again—what policies are in place to prevent accidents when police are playing with their new toys, or outright abuse? And what will this kind of power do to democracy?
The Army Lawyer report concludes by noting that
A user can, however, improperly employ the LRAD to cause intentional pain. When this happens, the LRAD transitions from being a communication device to being a non-lethal weapon. Nevertheless, the LRAD was intended to be used as a communication device, not a “weapon,” “gun,” or “sound cannon” to “inflict pain or even permanent deafness,” but even when improperly used as a non-lethal weapon, the LRAD would fully comply with the law of war, because the “discomfort” it can cause “is well short of permanent damage to the ear” it would not exceed the “threshold of superfluous injury or unnecessary suffering.
Until the public hears a not-so-loud-and-clear articulation of how police and others are using new tools like this, demonstrators facing an LRAD can rely on a very basic defense mechanism, one that also sounds like a metaphor for a politics defined by noise: earplugs.