Friday, 19 June 2020

Crowd Control with Long Range Acoustic Devices Can Cause Permanent Hearing Loss

Posted in ADA News

Long Range Acoustic Devices (LRADs) may be used as close range sonic weapons against U.S. citizens as a form of non-lethal crowd control and dispersion. These sonic weapons are capable of inflicting severe, debilitating, permanent harm on U.S. citizens in the form of irreversible hearing loss, tinnitus, vestibular dysfunction, and barotrauma.

Weaponized use of LRADs or other acoustic hailing devices against U.S. citizens should be banned and deemed a violation of 14th Amendment rights, prosecutable by law.

The Academy of Doctors of Audiology calls on Congress to restrict the use of these devices on protestors exercising their lawful First Amendment rights.


LRADs were developed for use as a sonic weapon by the military in the early 2000s, through an evolution of acoustic hailing devices with a primary function of long-range communication. LRADs are promoted to the commercial, government, and military markets and have been purchased by a number of police municipalities across the country. LRADs are often referred to as “sound guns” or “sound cannons”. Weaponized use of LRAD technology concentrates and directs harmfully loud and painful acoustic energy (sound) toward a target in a narrow beam.

LRADs have been utilized in connection with civilian protests and other First Amendment-protected activity, despite the recommendation by Physicians for Human Rights and the International Network of Civil Liberties Organizations to suspend the use of acoustic weapons for crowd control [1]. The first documented use of LRADs was against peaceful protesters at the 2009 G20 summit, resulting in pain and permanent hearing loss to both protesters and bystanders [2,3]. LRADs were used at protests in Ferguson, Missouri in 2014 [4], in San Diego in 2016, at the Washington Women’s March in 2017, and at Standing Rock [5], among others. LRADs were suspected in the assault on the US Embassy in Havana in Cuba in 2017. [6]

LRADs are available in a variety of models with a peak output range of 140 dB SPL to over 160 dB SPL at 1 meter. LRADs can transmit speech and acoustic information over long distances, up to 5 km or more. While the benefits of LRADs as a tool for critical communication are clear, their weaponized use as crowd control is undeniably hazardous. LRADs can cause pain using 110 – 130 dB SPL at 65 feet [7,8].

The National Institute of Occupational Safety and Health (NIOSH) and Centers for Disease Control and Prevention (CDC) recommended noise dosage ranges  from less than 2 minutes at 110 dB SPL to under 1/100,000th of one second at 162 dB SPL. LRAD use at 150 dB SPL would put anyone within 100 ft at risk of immediate permanent acoustic trauma.

Exposure to LRADs acoustical output puts civilians, bystanders, and law enforcement officers at risk. Individuals exposed to weaponized LRAD use at the 2009 G20 Summit experienced mild traumatic brain injuries, permanent hearing loss, tinnitus (ringing in the ears), eardrum perforation (holes), ear pain, dizziness, and disorientation [6,9,10]. There is little external research or medical literature on the effects of acoustic weapons such as LRADs on an individual [1], although the potential impact of excess noise exposure and acoustic trauma are well-documented.

According to the manufacturer (Genasys, Inc.), LRADs were used during the U.S. protests of June, 2020, in a number of cities – including Portland, Colorado Springs, San Jose, Phoenix, Columbus, Charleston, Ft. Lauderdale, and others. A lawsuit is currently in progress regarding New York City police use of LRAD against protesters in 2014. The case appears to be proceeding in favor of the plaintiffs, claiming excessive use of force and violation of 14th Amendment rights.[11] A prior suit filed by the ACLU against the City of Pittsburgh, regarding the use of LRAD at the 2009 G20 summit, was also ruled in favor of the plaintiffs.

The continued abusive use of LRAD as a weapon against U.S. citizens by police departments across the country demands action. No amount of guidance, training, or usage protocols can guarantee such abuse will not continue. Police departments implementing weaponized use of LRAD must be held accountable by law.

The Academy of Doctors of Audiology calls on police departments to cease the use of LRADs as a method of crowd control. Weaponized LRAD use should be banned and prosecutable by law. Because of the highly focused and intense sound delivered by LRADs, use as non-lethal crowd control is unacceptable and inhumane, and has the potential to cause immediate and irreversible hearing damage

The direct physical harm caused by weaponized deployment of LRADs on citizens cannot be denied. The capability of LRADs to cause permanent damage and injury constitutes an excessive use of force in violation of the Fourteenth Amendment [12]. The potential to cause permanent damage endangers not only protesters, but also journalists, observers, and other peaceful bystanders.


  1. Physicians for Human Rights & International Network of Civil Liberties Organizations (PMR & INCLO). (2019). Lethal in Disguise: The Health Consequences of Crowd-Control Weapons. Retrieved from
  2. Glassbeadian. (2009, September 26). Long Range Acoustic Device (LRAD) G20 Pittsburgh. Retrieved from
  3. Bowling, B. (2012, November 14). Pittsburgh to pay researchers who suffered hearing loss during the G-20 summit. Retrieved from
  4. Newman, L. H. (2014, August 14). This Is the Sound Cannon Used Against Protesters in Ferguson. Retrieved from
  5. Enzinna, W. (2016, October 31). I Witnessed Cops Using Tear Gas, Rubber Bullets, and Sound Cannons Against Anti-Pipeline Protesters. Retrieved from
  6. Randel L. Swanson II, DO. “Clinical Findings and Outcomes in US Government Personnel Reporting Directional Sensory Phenomena in Cuba.” JAMA, American Medical Association, 20 Mar. 2018,
  7. LRAD Product Overview. (n.d.). Retrieved June 4, 2020, from
  8. The National Institute for Occupational Safety and Health (NIOSH). (2018, February 6). Noise and Hearing Loss Prevention. Retrieved from
  9. Urbina, I. (2009, September 24). Protesters Are Met by Tear Gas at G-20 Conference. Retrieved from
  10. Weaver, M. (2009, September 25). G20 Protesters Blasted by Sonic Cannon. Retrieved from
  11. Edrei v. Bratton Np. 17-2065 (2d Cir. 2018) Retrieved from
  12. Edrei v. Maguire. (2018, June 13). Retrieved from