Trending Topics

How police are using soundwave technology for crowd control

Long Range Acoustic Devices are being embraced by law enforcement agencies as a powerful and versatile instrument of communication


New York City Police Sgt. Janet Jordan gives orders using a Long Range Acoustic Device during a training drill in preparation for the Republican National Convention, Thursday, Aug, 19, 2004 in New York.

AP Photo/Mary Altaffer

From crafting policy to tactical considerations, PoliceOne’s 2017 Guide to Emerging Technologies features expert analysis on soundwave technology, facial recognition software, handheld narcotics analyzers, the future of traffic stops, how constitutional law impacts the collection of data for investigations, and how advancements in biometric technologies will help improve correctional facilities.


The Long Range Acoustic Device, a hailing and audio broadcast tool, was developed as a direct result of the Oct. 12, 2000 attack on the USS Cole. Terrorists on a small boat blew a large hole in the USS Cole, killing 17 and wounding 39 sailors aboard. After the attack, the U.S. Navy saw a need for a tool to communicate with and turn away or stop potential attackers from greater distances.

Navy ships equipped with the LRAD can effectively hail, inform, direct or warn the operators of boats that are in distress, engaging in illegal activity or whose actions potentially pose a threat on the high seas.

LRAD is now being embraced by law enforcement agencies as a powerful and versatile instrument of communication with a wide range of uses.

LRAD explained

An LRAD unit is primarily a communication device that does two things under very difficult circumstances: It allows officers first to communicate clearly from a safe distance, and if no compliance is achieved, the device can be used to give a warning to targeted individuals or a large group.

LRADs can be mounted on vehicles, BearCats, boats and helicopters. There is even a handheld unit. They have been used by law enforcement agencies at large demonstrations, tactical standoffs, active shooter events and natural disasters, allowing officers to communicate in a clear and concise manner over long distances to inform, direct and warn people.

A trained operator can transmit a pre-recorded message or speak live via the microphone. The LRAD transmits the message so that it can be understood through crowd noise and over great distances. The message can even be sent in the targeted group’s language or dialect.

Crowd control

The LRAD first gained national attention for law enforcement use in 2009 when the Pittsburgh Police Department used it during the demonstrations at the G-20 Summit. Chiefs, sheriffs and tactical team commanders all over the country took notice.

The LRAD has multiple tactical applications. It has been used in standoffs to establish and maintain communication with suspects. It has been used to warn endangered people if they are approaching active shooter events. This tool also has been deployed by police in Houston, Oakland, Dallas, Chicago and New York during large demonstrations and disturbances, as well as during the riots in Ferguson, Missouri.

Many agencies are pre-recording commands to use during unlawful assemblies after having the verbiage approved in advance by their legal departments. Trained operators at these large events have been able to communicate with crowds and individuals from substantial distances. The San Diego Police Department used an LRAD in 2016 with great success, giving warnings in English and Spanish to a large group of protestors.

In the past these communications were done with bullhorns, but this technique has limitations. The LRAD sends the message out in a 15 to 30 degree beam, and the audio is so clear and understandable that it is nearly impossible for individuals arrested at violent demonstrations to successfully claim, “I couldn’t understand what the police were saying,” as a defense.

Non-lethal warning

Another aspect of the LRAD is the non-lethal warning tone, which can be directed at individuals or a crowd who, after ignoring commands, continue to advance aggressively on police. The warning tone, in most cases, causes targeted individuals to instinctively cover their ears and turn away and can repel these individuals without requiring physical force.

“LRAD is not a weapon,” said Robert Putnam of the LRAD Corp. “LRAD is a highly intelligible long-range communication system and the safer alternative to kinetic force.”

Because the technology is so new, law enforcement has yet to arrive at a universal protocol for reasonable use of the LRAD warning tone. The use of the tone by the NYPD during a disturbance in 2014 has been legally challenged by six individuals, and the court has not yet ruled on their claims.

Technical and tactical

LRADs have been used successfully by SWAT teams in standoffs, high-risk warrant arrests and while dealing with suicidal subjects. Crowd control units have used them to cut through the extremely loud noises generated during riots to inform, direct and de-escalate potential confrontations. For example, the Columbus (Ohio) Police Department acquired an LRAD unit for better crowd control after riots at Ohio State University.

The advantage of enhancing our communication capability in law enforcement is the decreased likelihood of use of force. When we are communicating, we are not fighting or shooting.

Tactical teams have crisis negotiators who have trained extensively to de-escalate situations, and an LRAD unit can support communication by these professionals in even more situations than previously possible.

Communications expert James Humes once said, “The art of communication is the art of leadership.” Leading law enforcement agencies are enabling their best communicators to resolve tough situations with their words to prevent property damage, injury and even loss of life.

Lt. Dan Marcou is an internationally-recognized police trainer who was a highly-decorated police officer with 33 years of full-time law enforcement experience. Marcou’s awards include Police Officer of the Year, SWAT Officer of the Year, Humanitarian of the Year and Domestic Violence Officer of the Year. Upon retiring, Lt. Marcou began writing. Additional awards Lt. Marcou received were 15 departmental citations (his department’s highest award), two Chief’s Superior Achievement Awards and the Distinguished Service Medal for his response to an active shooter. He is a co-author of “Street Survival II, Tactics for Deadly Encounters,” which is now available. His novels, “The Calling, the Making of a Veteran Cop,” “SWAT, Blue Knights in Black Armor,” “Nobody’s Heroes” and Destiny of Heroes,” as well as his latest non-fiction offering, “Law Dogs, Great Cops in American History,” are all available at Amazon. Dan is a member of the Police1 Editorial Advisory Board.