U.S. flag

An official website of the United States government, Department of Justice.

NCJRS Virtual Library

The Virtual Library houses over 235,000 criminal justice resources, including all known OJP works.
Click here to search the NCJRS Virtual Library

Can a Crying Baby Stop a Riot?

NCJ Number
Law Enforcement Technology Volume: 31 Issue: 3 Dated: March 2004 Pages: 8,10,12,14
Christa Miller
Date Published
March 2004
4 pages
This article describes current and future acoustic technology that law enforcement uses as less-lethal force.
Research has been on-going in the field of acoustic technology; current and future innovations may make acoustic options the less-lethal weapon of choice for law enforcement. The effects of acoustic sound on humans are reviewed, including research from the United Kingdom indicating that death can occur in humans exposed to 220 decibels. Challenges remain to the use of acoustic force for law enforcement purposes. Sound waves do not propagate well so that attenuation of the initial energy is rapid and extensive, making it difficult to focus the acoustic effect on a particular target. Another challenge is that sound affects people differently, adding an element of uncontrollability to the use of acoustic weapons. In order for a weapon to be used for law enforcement purposes, it must be completely predictable and controllable. The past 2 years have brought research that has overcome the problem of focusing and aiming sound at specific targets, making the technology extremely useful for several facets of public safety. American Technology Corporation’s (ATC) Long-Range Acoustic Device (LRAD) is described and applications for crowd control, access denial, and clearing buildings are discussed. Smaller, more portable versions of LRAD will soon be available for law enforcement purposes. Next, ATC’s NeoPlanar technology is described as delivering home theater sound over a large area. NeoPlanar technology makes sound “highly intelligible” and able to travel over wide areas, making it an effective means of delivering voice commands or music over a large geographic area. ATC’s Hypersonic Sound (HSS) uses ultrasound as a carrier frequency, which amplifies and emits sound. It operates like a flashlight, aiming sound at particular locations. The article next reviews acoustic weaponry that is currently under development, including ATC’s “sonic bullet.” Up and coming acoustic technologies offer less-lethal weapons that also incorporate the ability to communicate. Table