High-Intensity Acoustics for Military Nonlethal Applications: A Lack of Useful Systems

Military Medicine, Feb 2007 by Jauchem, James R, Cook, Michael C

There have been many previous claims of nonlethal acoustic weapon effects, mostly in the popular rather than the scientific literature. Anecdotal reports of extraordinary effects can make meaningful assessment and review of this area very difficult. Acoustics research has shown that the nonlethal weapon capabilities of audible sound generators have been grossly overstated. Although high-intensity infrasound significantly disrupted animal behavior in some experiments, the generation of such energy in a volume large enough to be of practical use is unlikely because of basic physical principles. On the basis of experimentation completed to date at a number of institutions, it seems unlikely that high-intensity acoustic energy in the audible, infrasonic, or low-frequency range can provide a device suitable for use as a nonlethal weapon.

Introduction

Acoustic energy includes sound in the audible frequency (2020,000 Hz) and infrasound (

The purposes of this article are to review anecdotal and laboratory reports of acoustic weapon effects and to assess the potential usefulness of high-intensity acoustic energy in nonlethal weapon applications, particularly in relation to psychological effects. Potential underwater applications are not discussed in this article.

In addition to journal articles, books, and book chapters (i.e., "publications" as strictly defined by Easterbrook et al.3), items from the so-called "gray literature"4 (such as abstracts, proceedings of meeting presentations, conference reports, technical reports, patents, and official government documents) were used for this review. Items were identified from the following electronic databases: National Library of Medicine PubMed (including Medline), Biosls, Embase, Toxicology Literature Online (Toxline Special), Developmental and Reproductive Toxicology/Environmental Teratology Information Center database, Agricola, Inspec, JICSTEPlus (Japanese Information Center for Science and Technology), Pascal (Institut de l'Information Scientifique et Technique, Centre National de la Recherche Scientifique), CAB Abstracts, Chemical Engineering and Biotech Abstracts, Life Sciences Collection, SciSearch, National Technical Information Service, Applied Science and Technology Abstracts, Academic Search Premier, Master File Premier, Psychinfo/Psychological Abstracts, Aerospace Database, and Online Computer Library Center FirstSearch (including General Science Index, Applied Science and Technology Index, Electronic Collections Online, and ArticleFirst). Accounts from newspaper articles were not included.

Previous Claims of Acoustic Weapon Effects

Audible Frequencies

A prototype "acoustic blaster" was described as "developed and tested successfully."5 Another acoustic weapon prototype was alleged to produce effects "ranging from minor annoyance to total incapacitation."6 Arkin7 suggested that acoustic weapons were so far advanced that deployment was imminent.

A complex waveform acoustic device was described as a prototype nonlethal weapon.8,9 It was later portrayed as "a viable crowd deterrent."10 Van Williams11 listed several acoustic nonlethal weapons "in advanced test and evaluation stages." A device that could cause "emission of an acoustical pulsed periodic stimulus" that "effectively suppresses determined human operations" was mentioned by Rynne.12 Lewer and Schofield13 stated that acoustic weapons developed by Scientific Applications & Research Associates were at an advanced stage of production. Rappert and Wright14 noted that acoustic weapons "are thought to offer unprecedented options" in nonlethal applications.

The United Kingdom has implemented export controls for "acoustic devices represented by the manufacturers... as suitable for riot control purposes."15 More recently, a device nicknamed the "acoustic bazooka," more formally known as the directed stick radiator or high-intensity directed acoustics, was developed to serve as either a voice-hailing signal device16 or supposedly a nonlethal weapon that makes "people turn as green as grass" with sickness.17 The original research effort, however, consisted of equipment development and was not intended to evaluate aversive effects on humans.16 No results of any such testing have been published, to date, in the scientific literature. It has been suggested that the device could "have the capacity to knock people off their feet."18 A "long-range acoustic device" has been deployed by the U.S. military in Iraq and by the New York Police Department.19 The device was intended for use as a communication device, however.20 Although some news outlets have referred to recent uses of the long-range acoustic device (e.g., on a cruise ship on November 7, 2005(21)) as "nonlethal weapon" deployment, such systems are still described by the manufacturer as "designed beneath pain thresholds" and "not nonlethal weapons."22 They have been represented elsewhere as devices "designed to modify the behavior of personnel with a high intensity warning tone"23 and to "deliver a shrill 145 dB tone . . . causing headaches and panic."24