By: Erin Kidd

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[1]       An LRAD, short for long-range acoustic device, was used against American protesters for the first time at the G20 Summit Pittsburgh protests in September 2009.[1] Over the past decade, LRADs have only become increasingly popular among law enforcement, to the point where the device is now a common feature of many department’s crowd control arsenals.[2] The device’s use, particularly during protests, is increasingly controversial and contentious and one case in the Second Circuit may change how law enforcement uses this technology.[3]

The LRAD Device

[2]       The LRAD was originally designed for the military as both an acoustic hailing device (AHD) to broadcast commands over long distances and as a painful repellant for approaching enemies.[4] However, the developer of LRAD, which was first known as the American Technology Corporation until 2010 and very recently rebranded from the LRAD Corporation to Genasys in late October 2019,[5] has been adamant in maintaining the LRAD is not a weapon.[6] Despite this, the devices are often referred to as sonic or acoustic weapons and the media coined the term “sound cannon” in order to describe the nature of the LRAD’s capabilities.[7]

[3]       The sound produced by the LRAD is directed forward in a “beam” that is about fifteen to thirty degrees wide.[8] This can be used to broadcast just about anything, from live commands to recorded music, and it is less controversial than the LRAD’s second possible setting, the deterrent alert tone or “area denial function.”[9] The “area denial” tone comes in the form of a manually controlled series of sharp, piercing beeps which can hit the peak decibel capabilities of the device.[10] More than anything else, it is this setting that have led many to refer to the LRAD as a weapon.[11]

[4]       The military-grade versions of the LRAD can transmit sounds up to five and a half miles away at a potential maximum level of 162dB.[12] For comparison, 140dB is roughly equivalent to standing next to a jet engine while a plane takes off or having a shotgun go off next to a person’s ear.[13] According to ASHA, the American Speech-Language-Hearing Association, sound usually starts to be severely painful at 120dB and once sounds which reach 140dB or higher are not safe for any period of time, meaning they can cause instant and permanent damage.[14] Much lower levels can still cause pain and permanent harm, often it just becomes a matter of how long a person was exposed.[15]

[5]       The models preferred by law enforcement, which seem to be the LRAD 500X and the 100X, are not quite as powerful as the military-grade version.[16] However, at apparent maximum levels of 137-140dB and 149-154dB respectively, both are still capable of causing severe pain, disorientation, nausea, migraines, and permanent damage.[17] Though an informational packet from the developer seems to suggest otherwise.[18]

[6]       It seems that, at least as of early 2018, many police departments using LRADs lacked specific training and written policies for use of the device.[19]

The Second Circuit and Sound as a Use of Force

[7]       LRAD has some definite potential benefits, particularly in how it can be utilized to communicate in emergency situations, however, a case in the Second Circuit may help determine the extent to which it can be used against civilians.[20] The case, which was heard as Edrei v. City of New York[21] in the district court and Edrei v. Maguire[22] in the Court of Appeals for the Second Circuit, arose from the NYPD’s use of an LRAD 100X during the 2014 Black Lives Matter protests which followed a grand jury’s refusal to indict Officer Daniel Pantaleo in the killing of Eric Garner.[23]

[8]       Anika Edrei, a photojournalist who was a photography student at the time of the protest, and five other plaintiffs witnessed, but did not interfere with, NYPD officers arresting protesters around the early hours of December 5, 2014.[24] During the arrests, some unknown protesters likely threw glass bottles towards the police and a few others began throwing trash at the street.[25] In response, officers ordered everyone present to return to the sidewalk and some officers began deploying pepper.[26] Two officers began using the LRAD 100X’s to direct people out of the street and, while doing so, they utilized the LRAD’s area denial function “deterrent tone” fifteen to twenty times in the course of about three minutes.[27] Plaintiffs described the use of the tone being used “indiscriminately” and “almost continuously.”[28] Also according to plaintiffs, the officers “fired” the deterrent tone, with the LRAD pointed in their direction, while less than 10 feet away from the plaintiffs and other protesters, photographers, filmmakers, and observers.[29] Per some of the court documents, it seems the LRAD may have had specific warnings posted on it, warning against using the device at such a close range.[30]

[9]       The plaintiffs seem to have suffered migraines, sinus pain, dizziness, facial pressure, ringing in ears, and ongoing sensitivity to noise.[31] One plaintiff was diagnosed with tinnitus in both ears and vertigo which continued even a year and half later.[32] Another experienced hearing loss caused by nerve damage.[33]

[10]     The plaintiffs initially claimed violations of their First Amendment rights, their Fourth and Fourteenth Amendment rights against unreasonable seizure and excessive force under, their rights to equal protection under the Fourteenth Amendment, as well as various other claims.[34] The defendants filed a motion to dismiss, mostly based on qualified immunity.[35] On May 31, 2017, Judge Robert Sweet of the United States District Court for the Southern District of New York granted the motion to dismiss for all but two claims: the Fourteenth Amendment excessive force claim and an assault and battery claim.[36]

[11]     Judge Sweet determined, through comparing the potential harm that can come from the LRAD’s amplified sound to what can happen when “distraction devices” such as stun grenades and flashbangs are used improperly, that the LRAD’s sound was a use of force and it could be used excessively.[37] He further decided the defendants’ defense of qualified immunity was “unavailing” at the motion to dismiss stage and whether or not it applied would need to be determined by the facts of the case.[38]

[12]     When defendants appealed this decision, the Second Circuit Court of Appeals agreed on both counts.[39] In finding the LRAD sound was a use of force the court explained “a device that has ‘incapacitating and painful effects’ when used on a person is considered an instrument of force.”[40] The Appeals Court also agreed with analogizing the LRAD with other other “non-lethal” options available to officers that have been litigated about in the past.[41] In showing that qualified immunity could not dismiss the case at this stage the court explained a reasonable officer, through analogy to standards for use of pepper spray and stun grenades, would have known that excessive force from the LRAD would violate a “clearly established” right.[42]

[13]     The Appeals Court ultimately affirmed the lower court’s decision and remanded the case for further proceedings.[43] This May, the Supreme Court of the United States denied certiorari on the case, which will allow the case to proceed on those findings.[44]

[14]     If the plaintiffs win, not only will they be afforded damages, but the NYPD may face an injunction on using the LRAD devices they own until more studies about the LRAD’s effects are available and appropriate policies, guidelines, and trainings are in place.[45]


[1] See, e.g., Matthew Weaver, G20 Protesters Blasted by Sonic Cannon, The Guardian (Sept. 25, 2009, 5:19 AM),

[2] See, e.g., Alex Pasternack, The New Sound of Crowd Control, Vice (Dec. 17, 2014, 10:15 AM),

[3] See, Alex Pasternack, Piercing Sound Can Be Excessive Force, Federal Court Rules, Fast Company (June 14, 2018),

[4] See, e.g., Ben Kesslen, ‘Plug Your Ears and Run’: NYPD’s Use of Sound Cannons Is Challenged in Federal Court, NBC News (May 22, 2019),

[5] See LRAD® Corporation Rebranding as Genasys Inc. to Reflect Broader Commitment to Critical Communications, Genasys: Press Releases, (Oct. 23, 2019)

[6] See, e.g.,Halley Bondy, How the LRADWent From a Pirate Deterrent to a Police Crod-Control Tool, The Daily Beast (Sept. 30, 2019, 11:20 AM),

[7] See, id.

[8] See, e.g., Roberto Baldwin, What Is the LRAD Sound Cannon?, Gizmodo (Aug. 14, 2014, 11:40 AM),

[9] See Kesslen, supra note 4; Pasternack, supra note 3.

[10] See, e.g., Pasternack, supra note 3.

[11] See,e.g., Kesslen, supra note 4; Pasternack, supra note 3.

[12] See Baldwin, supra note 8.

[13] See Decibel Levels, Hearing Health Foundation, (last visited Nov. 22, 2019); Paul Virostek, Sound Effects Decibel Level Chart, Creative Field Recording (Nov. 1, 2017),

[14] Loud Noise Dangers, ASHA,

 (last visited Nov. 22, 2019).

[15] See, e.g., Decibel Exposure Time Guidelines, Dangerous Decibels, (last visited Nov. 22, 2019); How Loud Is Too Loud?, OSHA, (last visited Nov. 22, 2019).

[16] See Baldwin, supra note 8.

[17] See Curtis Waltman, Police Across the Country Are Adding Sonic Weapons to Their Crowd Control Arsenal, MuckRock (Feb. 5, 2018), (analyzing LRAD product white pages and other documents received from FOIA requests sent to the Chicago and Houston Police Departments as well as the Massachusetts State Police).

[18] See id.

[19] See Bondy, supra note 6.

[20] See Edrei v. Maguire, 892 F.3d 525 (2d Cir. 2018), cert. denied 139 S. Ct. 2614 (2019)

[21] Edrei v. City of New York, 254 F. Supp. 3d 565 (S.D.N.Y. 2017).

[22] Edrei, 892 F.3d at 525.

[23] See Kesslen, supra note 4; Pasternack, supra note 3

[24] See Edrei, 254 F. Supp 3d at 571.

[25] See id. at 571—72.

[26] See id. at 572.

[27] See id.

[28] See id. at 576.

[29] See id. at 572.

[30] See,e.g., Kesslen, supra note 4.

[31] See Edrei, 254 F. Supp 3d at 572.

[32] See id.

[33] See id.

[34] See Edrei, 254 F. Supp. 3d at 573—83.

[35] See id. at 570, 576.

[36] See id. 577, 582.

[37] See 575.

[38] See 576.

[39] Edrei, 892 F.3d at 545

[40] See id. at 543.

[41] See id. at 542—43.

[42] See id.

[43] See id. at 545.

[44] Maguire v. Edrei, 139 S. Ct. 2614 (2019).

[45] See,e.g., Kesslen, supra note 4.


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