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I New York City Police DepartmentSpecial Operations vision

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I. Introduction

In 2004, the New York City Police Department's Disorder Control Unitpurchased two (2) LRAD (Long Range Acoustical Device) model 3300 devices from theAmerican Technology Corporation of San Diego California. The NYPD purchased the

devices in anticipation of using them at the Republican National Convention in NewYork City in August, 2004'

The LRAD is a machine that uses innovative technology to propel sound overgreat distances. Although it can be thought of as a loudspeaker , it actually worksdifferently and may also be used as an area denial device for crowd managementpurposes. The LRAD is the size of a large truck tire, but much thinner, wighsapproximately 451bs, and can be mounted on a free standing tripod device or on avehicle. Some newer models are portable and can be carried in one hand.

The LRAD was created partially in response to the 2000 terrorist attack on the

USS Cole, a U.S. Navy destroyer which was attacked while in port in Yemen. The attackwas perpetrated by the use of a small boat, laden with explosives, which rammed into theUSS Cole, killing seventeen sailors and injuring dozens more.

In addition to having loudspeaker capabilities, the device can also be used, in aspecial mode, to propel piercing sound at higher levels (as measured in decibels) than areconsidered safe to human ears. In this dangerous range (above 120 decibels), the devicecan cause damage to someone's hearing and may be painful. It is this technology thatdevice was designed for a USS Cole attack-type scenario. If mounted aboard a Navyship, the device's loudspeaker could be used to warn off' boats that come too close. Ifthose warnings are ignored, the device could be used to send out sound at a dangerously

high level causing attackers to tum away, or at least, to cause pain/hearing damage to tryto repel the attack. -

The LRAD devices purchased by the Disorder Control Unit were deployed duringthe Republican National Convention in 2004, for use as loudspeakers. One device wasmounted on a marked NYPD Humvee truck, and the other on a marked 3-wheeledscooter. It was thought that the scooter could be used in situations where it'smaneuverability in traffic and in parks would allow for use of the device in areas theHUMVEE could not get into.

Both devices were used spor.adically in Manhattan at protests outside of theconvention site (Madison Square Garden), including those in the Union Square area. Inall cases, the device was used as a loudspeaker to make announcements to the crowd ofprotesters, with mixed results. No injuries were sustained as a result of the use of eitherLRAD at the convention.

LRAD devices (newer versions) were used successfully by the Pittsburgh,(Pennsylvania) Police Department during the G-20 Summit Conference in 2009.

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II. Technology

Sound travels in waves, and generally spreads in all directions from a source , inthe form of a w ave front. As the w aves travel farther from their sources, they spreade ve n w ide r, e ffe ctive ly low ering the volum e of the sound.

The L RA D de vice produce s sound through the use of pie zoe le ctric transduce rs,rathe r than the traditional diaphragm use d by loudspe ake rs. T his allow s a gre ate r volum eo f sou nd .

The LRAD also used directional sound, in that it focuses the sound waves in aspecific direction. W hile the sound being emitted from in front of the LRAD may beve ry loud, it is substantially quie te r outside the c one of sound produce d by the de vice .In fact, someone could stand next to the device or just behind it and hear the noise beingem itted at m uch low er leve ls than som eone standing several hundred fee t aw ay, butw ithin the con e o f sou nd b eing e mitte d.

Some examples of sound levels for comparison, in decibels (dB):

WhisperN orm al sp ee chTele phone D ial ToneVacu um C le an erSustained exposure may cause hearing lossSubway at 200 fee tMotorcyclePow er SawSandblastingPain may beginShot gunShort term exposure can cause permanent damageLRAD sustained at maximum power/audioEar drum breaks

30dB60dB80dB85 dB9 0-9 5 IB95 dB105110

1151 20 -1 25 d H120140dH146dH160 dB

Sources : www.osha.gQYwww.esoundproof.comwww.makeitlouder.comwww.gaudio.co 11www/science.howstuffworks.com/lrad.htm

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III. Testing

The results of tests conducted by the Disorder Control Unit in 2004 are unavailable.More recently, in early 2010, DCU staff tested both of their LRAD devices in anempty parking lot at Orchard Beach, in the Bronx. The devices were set on tripodsapproximately five feet tall, and the sound was directed from one end of the parkinglot toward the other.

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Notes: Distances were calculated by measuring parking spaces (eight feet wide)and counting the number of spaces that our testing meter was located awayfrom the LRAD.

While the extreme cold (28 degrees) ensured that no one was at the beachor in the lot, the accompanying wind may have had an effect on the resultsof the test.

The sound meter used was the same as currently used by the NYPD, withappropriate calibration tests.

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LRAD @ southEnd of parking lotFacing north

Potential dangerarea

Not tested

Test 1- Power/Audio

turned to level justbelow Maximum,using spoken voice

commands

102 dB at 40 parking spots away (320 feet)

78 dB at 80 parking spots away (640 feet)

64 db at 100 parking spots away (800 feet)

Unintelligible/barely heard (no register on meter) at 140 parking spots away (1120 feet)

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LRAD @ southEnd of parking lotFacing north

Potential dangerarea

Not tested

Test 2- Power/Audioturned to Maximum,

using noise bursts

110 dB at 40 parking spots away (320 feet)

90 dB at 80 parking spots away (640 feet)

68 db at 100 parking spots away (800 feet)

Unintelligible/barely heard (no register on meter) at 140 parking spots away (1120 feet)

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Photo taken from rearof LRAD device

showing tripod mount...:lh,;jJ~: i