Conference PaperPDF Available

Acoustic Weapons



Acoustic (or sonic) weapons are under research and development in a few countries and have been the subject of interest and much speculation for several decades. Such devices have repeatedly captured the interest of the press, most recently when it was reported in 2016 that several staff members at the American embassy in Cuba were allegedly ‘subjected to an “acoustic attack” using sonic devices’ that caused serious health problems. Neurol- ogists and engineers have challenged this claim. Although a few acoustic devices exist today that could be used as weapons, and sound is implicated in the use of force in the military and law enforcement domains in various ways, the potential for weaponization of acoustic devices has likely been overstated. Nevertheless, consideration of acoustic weapons brings to the fore a number of issues that deserve attention from the perspective of multilateral weapons control.
Acoustic (or sonic) weapons are under research and development
in a few countries and have been the subject of interest and much
speculation for several decades.1 Such devices have repeatedly
captured the interest of the press, most recently when it was
reported in 2016 that several staff members at the American em-
bassy in Cuba were allegedly ‘subjected to an “acoustic attack”
using sonic devices’ that caused serious health problems.2 Neurol-
ogists and engineers have challenged this claim.3
Acoustic weapons aim to use the propagation of sound – a variation
in pressure that travels through a fluid medium (such as air) to affect
a target. Most of the acoustic weapons that have been speculated
upon are based on either ultrasound (above 20 kilohertz, kHz),
low frequencies (below 100 hertz, Hz) or infrasound (below 20 Hz)
deployed at high levels.4 The human range of hearing is commonly
given as between 20 Hz and 20 kHz. In reality, the upper hear-
ing-threshold frequency decreases significantly with age, whereas
sounds with lower frequencies can be heard and otherwise perceived
if the level is high enough.5
Although a few acoustic devices exist today that could be used as
weapons, and sound is implicated in the use of force in the military
and law enforcement domains in various ways, the potential for wea-
ponization of acoustic devices has likely been overstated.6 Recent
scientific analyses have debunked myths and disproven earlier claims
about the effects of acoustic devices on humans and have drawn
attention to the practical limitations of such technologies.7
Nevertheless, consideration of acoustic weapons brings to the fore
a number of issues that deserve attention from the perspective of
multilateral weapons control, including within the framework of the
Convention on Certain Conventional Weapons (CCW):
x Often branded as ‘non-lethal’ or ‘less lethal’,8 acoustic devices
are open to the same questions and criticisms levelled against
other technologies given that label (including that they may
undermine boundaries distinguishing acceptable modalities of
force in war-fighting and in law enforcement, and that their use
in conjunction with kinetic weapons actually increases the risk of
x Acoustic weapons raise questions of delineation between devices
specifically designed to harm through acoustic phenomena
like sound or vibration (acoustic weapons properly speaking),
other weapons with harmful acoustic effects (such as explosive
weapons) and the use of organized sound (music) or unorganized
sound (noise) by militaries and police, including to torture or ter-
rorize. Such delineation in turn has consequences for national and
international control and raises further questions about the role of
international regulation.
x Consideration of acoustic weapons raises the question of our
orientation towards technologies that target the human senses
(‘sensory violence’). Parallels that could be drawn from the prohi-
bition on blinding laser weapons (formalized in CCW Protocol IV)
and the opprobrium attached to blinding as a method of warfare
deserve further exploration in light of the evolving understanding
of deafness and blindness from a health perspective.
x Consideration should be given to the ethical, health, legal and
environmental concerns about the acceptability and desirability of
acoustic violence – sound as a technique of authority and control9
– especially in frequencies beyond the human audible range,10
Acoustic Weapons
Discussion paper for the Convention on
Certain Conventional Weapons (CCW)
Geneva, November 2018*
Article 36 is a UK-based not-for-profit organisation working to promote public
scrutiny over the development and use of weapons.
* This paper was written by Maya Brehm and Anna de Courcy Wheeler. The
bulletin was updated on 3 December 2018 to note the position of Cuba in
footnote 2.
Acoustic hailing devices (AHD) or ‘sound cannons’
AHD operate in the audible range and issue high-energy acoustic
beams to communicate with, warn and potentially disorient or disable
a person. A number of states have developed and are using such
systems,20 in both military and law enforcement settings, primarily in
connection with crowd and border control. Such devices can report-
edly produce ‘harmful, pain-inducing tones’ over some distance,21
and can damage the human ear and even cause permanent hearing
loss over short distances.
The best-known of these devices is the Long Range Acoustic Device
(LRAD). It resembles a flat loudspeaker that uses many piezoelec-
tric transducers, set in a staggered arrangement.22 The LRAD was
developed as a military tool to enforce exclusion zones around naval
vessels following an attack on the navy warship USS Cole in Yemen in
2000. It has subsequently been used by the US navy to protect ship-
ping lanes around the Iraqi port of Basra and nearby oil terminals.23
It has also reportedly been used for ‘hailing and warning’ by cruise
and transport liners to deter pirates,24 been deployed by police forces
in several countries25 and is being attached to drones.26
The LRAD has relatively high directivity (with a beam opening angle
of 5–15 degrees) and transmits mainly high frequencies (above 1
kHz). The LRAD 1000 projects voice messages to a range above 500
m, and warning tones to above 1000 m.27 Various, scaled-down and
scaled-up versions are available.28
There are also reports that similar devices, termed ‘sonic blasters’,
have been used to produce a series of high-intensity blasts (high
levels of sound pressure and volume) to affect a target rather than
to communicate. Among the most reported examples are Israel’s
sonic pulser, ‘The Scream’,29 and its ‘Thunder Generator’, originally
developed as ‘an environmentally friendly soil-disinfection machine’
to scare away birds from crops, and later used for riot control.30
Flash-bang devices
Flash-bang devices (or ‘noise flash diversionary devices’) contain
mixtures of fast-burning propellants and pyrotechnics to produce a
loud ‘bang’ and a bright flash of light. They often take the form of
grenades (‘stun grenades’, ‘flash-bang grenades’, ‘sound bombs’)
that are deployed by hand or from shotgun cartridges.31
Flash-bang grenades are in widespread use by military and law en-
forcement actors and are designed to temporarily blind, disorient and
cause dizziness. As the casing is not intended to produce fragmenta-
tion during detonation, such flash-bang devices are typically labelled
‘non-lethal’. There are, however, several known cases of serious injury
and death resulting from their use.32
A US performance characterization study of selected flash-bang
devices noted that one of the concerns associated with their use ‘is
the high level of sound generated by them, with respect to hearing
impairment or damage’.33 All of the devices tested in the study ex-
ceeded the US Department of Defense’s 140 decibel (dB) threshold
requirement for use of hearing protection. According to one source,
the ‘threshold noise’ of a flash-bang device ‘can reach 180 dB in
and the expansion of weaponized sound into civilian spheres. As
with directed energy weapons, some acoustic weapons may raise
questions about systems where the source of harm is not identifi-
able or comprehensible to those experiencing it.
x Given the well-documented health impacts of weapon noise
on humans, consideration of acoustic devices also raises the
question of whether political measures should be taken at the
international level to better protect both civilians and soldiers from
weapons that cause noise-induced hearing loss.
x Finally, there is concern that a lack of reliable, scientifically sound
and peer-reviewed data on the specifications and effects of acous-
tic devices11 has in the past driven research and development
(including animal testing) into acoustic weapons in expectation
of unrealistic potential. This has contributed to speculations and
public anxiety about acoustic, especially infrasound, weapons.
Current state of play
The fascination that acoustic weapons prompt among certain
militaries, police forces, journalists, scientists and publics has to be
understood against the backdrop of a complex and long-standing
relationship between sound, war and violence.12 What accounts of
such diverse phenomena as the Nazi-German ‘Windkanone’, Soviet
‘psychocorrection methods’, the US ‘Urban Funk Campaign’, the Brit-
ish ‘Curdler’ and the use of sound to torture,13 harass, intimidate or
terrorize14 have in common is a long-standing belief (justified or not)
in the destructive power of sound and vibration. This belief and the
search for bloodless, so-called ‘non-lethal’ technologies of violence,
which intensified from the early 1990s, have driven some states,
mainly the US, to push research and development into acoustic
weapons, especially in the infra- and ultrasonic frequency ranges.
Decades of research and development and considerable hype not-
withstanding, the potential for weaponization of acoustic devices has
likely been overstated.15 Inherent difficulties in projecting sound en-
ergy to tactical ranges, as well as limited human effects in practice,16
have hampered the attempts of states and scientists to produce an
acoustic-based weapon that can be fully operationalized. Low fre-
quency and infrasound can travel over considerably larger distances
than higher-frequency sound and are hardly attenuated through
dissipation.17 However, at low frequency, sound cannot be projected
in a directed beam; at higher frequency, it can. But if high-frequency
sound waves are to have an impact on humans, the sound pressure
would need to reach such a level that the sound waves become de-
formed.18 In order to produce such effects, the sound source with its
auxiliary equipment would be of a weight and dimension that could
not easily be carried by a single person, limiting practical military and
law enforcement applications.19
Certain types of acoustic devices currently reported to be in use by
law enforcement or military actors have drawn particular attention –
and criticism – and raise questions that are of interest from the per-
spective of multilateral weapons control more broadly. These include
acoustic hailing devices, flash-bang devices, and high-frequency
devices, all briefly described below.
is not only a humanitarian concern, but it also challenges democratic
control over the use of force and enables misconceptions and specu-
lations to endure about the effects of acoustic devices, justifying the
allocation of funds for further research and development, with poten-
tially negative consequences for international and human security.
Governance and regulation
‘Acoustic weapons’ or ‘acoustic devices’ are not authoritatively
defined or regulated in international law, nor are they the subject
of dedicated multilateral policy discussions.46 The potential to use
acoustic devices to communicate or warn, as well as to compel,
intimidate or injure, for domestic law enforcement and military
purposes (as well as by private citizens), has sparked debate in legal
quarters about how such devices, in particular the LRAD, should be
properly categorized. Some argue that they are hailing devices that
should neither be subject to national weapons reviews, including
those warranted by Article 36 of 1977 Additional Protocol I,47 nor to
export controls applicable to weapons.48 Others have taken the op-
posite view.49 A NATO study, for instance, describes ‘acoustic devices’
as ‘[w]eapons utilizing acoustic energy to induce human effects
through the sense of hearing or through the direct impact of pressure
waves on other parts of the human body’.50
The question of categorization aside, a number of existing regulatory
frameworks constrain the use of sound in connection with the use
of force, notably international humanitarian law (IHL) and interna-
tional human rights law (IHRL), as well as national health and safety
standards. In relation to the conduct of hostilities, the question is
often asked whether the use of acoustic devices would comply with
the IHL prohibition on the use of weapons and methods of warfare of
a nature to cause superfluous injury or unnecessary suffering.51 The
US, for example, has determined that the LRAD does not violate that
legal threshold, ‘because the discomfort is well short of permanent
damage to the ear’.52 An earlier preliminary assessment by the US
Navy had concluded that even ‘aural systems that could cause per-
manent hearing loss’ would not be illegal.53 At the international level,
the debate is complicated by divergent interpretations of the rule on
superfluous injury and continued disagreement about the (il-)legality
of blinding (and thus, by analogy, deafening) as a method of warfare.
In this connection, it is sometimes proposed that a prohibition on
acoustic weapons could be derived, by analogy, from the prohibition
on blinding laser weapons,54 another ‘non-lethal’ technology that
targets the human senses. This argument has been rejected on
the grounds that ‘the eye provides 90% of sensory input, the ear
accordingly provides much less. Moreover, permanent hearing loss is
not necessarily complete loss and prolonged hearing loss means that
such loss is only temporary’.55 Such a statement betrays a common
bias that ranks vision over other senses (ocularcentrism)56 and fails
to take account of evolving understandings of deafness (and blind-
ness) from medical and public health perspectives. It also speaks to
a lack of in-depth and critical consideration of sound and the ‘acous-
tic authority’ of the state (the ‘politics of frequency and amplitude’)57
in contemporary legal thought.58
Legal commentators have further pointed to the great potential for
indiscriminate effects from the use of acoustic devices, which may
violate the IHL rule on distinction and the prohibition of indiscrimi-
nate attacks.59 Testing has shown that the LRAD, for example, does
closed spaces, where the effects of the acoustic signature can be
compounded’.34 This is comparable to the peak levels of heavy artil-
lery (measured at the shooter’s position close to the gun).35
High-frequency devices
The particularity of high-frequency devices is that they emit a sound
at a frequency on the border of being ultrasonic, which is intended to
be heard only by younger people, whose ears tend to be more sensi-
tive to sound at high frequency compared to most older people.
The best-known model is the ‘Mosquito Teenager Deterrent/Anti-Loi-
tering Device’. This was initially developed to disperse vermin and
is now primarily marketed to private persons and businesses ‘for
dispersing groups of misbehaving teenagers’.36 According to the man-
ufacturer, the Mosquito MK4 can be set to emit a sound at 17 kHz
that only people under 25 can hear or at 8 kHz, audible to people of
any age, with four volume/distance settings and a maximum volume
of 103 dB.37
Adverse effects and risks
Acoustic devices can produce a range of harmful effects, most
notably temporary and permanent hearing loss, as well as pain, dis-
orientation, sensations of discomfort and nausea.38 Importantly, the
physiological and psychological effects of sound on humans depend
not only on frequency, but also on sound pressure levels, duration
and number of exposures and recovery time between exposures.39
And, effects vary significantly from one individual to another.
At 120 dB, where discomfort typically begins, there is a high risk of
hearing loss even for short and few exposures. Lasting damage to the
ear can occur at levels below the threshold for ear pain, which sets
in at between 135 and 162 dB depending on frequency.40 At extreme
levels, physical damage to organs of the ear can occur even with
short exposure.41 At about 160 dB, sound in the audio region causes
eardrum rupture. Infrasound at high levels can produce aural pain
and damage, a sensation of pressure in the middle ear and annoy-
ance, but it does not have the profound effects often associated with
it.42 Ultrasound at extreme levels (close to 160 dB) was reported to
produce a slight heating effect that could be felt on the skin.43
As with other technologies labelled ‘non-lethal’, the use of acoustic
devices has attracted strong criticisms from humanitarian, health
and human rights perspectives. In a war-fighting context, concern has
been raised that when an acoustic device is ‘used in a pre-lethal way
to incapacitate before killing’ it actually increases the ‘killing power
of lethal force’ rather than reducing casualties.44 Critics also object
to the extension of weaponized sound to (domestic) law enforcement
and the associated blurring of the boundaries of acceptable ways of
applying force. In a number of concrete situations, users were consid-
ered to have taken insufficient care to protect the lives and health of
people within the range of acoustic devices, and to account for the
specifics of a situation and individual differences in susceptibility to
injury and trauma.45
More generally, critics complain of a lack of proper documentation
regarding effects at various frequencies and levels in actual-use
situations, as well as a lack of analyses by independent bodies. This
as well as a ban on particular types (such as certain mobile LRAD)
and a requirement to document any use of a device automatically.77
Taking a precautionary orientation, Amnesty International and Omega
Research Foundation recommend that the use of acoustic devices
in the alert function be suspended ‘until an independent body of
medical, scientific, legal and other experts has subjected the effects
and potential uses of the type of device in question to rigorous
assessment and can then demonstrate a legitimate and safe use of
the device for law enforcement subject to specific operational rules
consistent with human rights standards.’78
Measures on acoustic weapons at the national and international
levels can build on a rich literature on non-lethal weapons in the
use of force, including detailed recommendations on selection,
testing, deployment, operational procedures, training, monitoring
and accountability, for multilateral controls as well as specific legal
not only affect those targeted by the device but also bystanders in
the directional periphery.60 Especially at longer ranges, questions
arise regarding the controllability of the propagation of sound, as ‘the
transmission direction will be deflected in case of strong winds’61 or
reflected off surfaces in built-up environments.62
The ‘indiscriminateness’ of acoustic devices is also a major human
rights concern. Pertinent international standards on the use of force
in law enforcement operations require that ‘the development and
deployment of non-lethal incapacitating weapons should be carefully
evaluated in order to minimize the risk of endangering uninvolved
persons, and the use of such weapons should be carefully con-
trolled.’63 In several cases, legal challenges have been brought over
injuries caused by the use of flash-bang devices in law enforcement
situations64 – use that raises questions concerning the rights to life
or health, and freedom of peaceful assembly and movement where
the devices were used for crowd control.65
Moreover, acoustic devices that target the hearing of a group of peo-
ple on the basis of their age, as does the Mosquito, raise issues re-
garding the right to equality and non-discrimination and from a child
rights perspective.66 The device has been declared illegal in some
jurisdictions.67 Devices that are inaudible (to adults) also raise a rule
of law concern as affected populations may face formidable challeng-
es in accessing an effective remedy.68 Finally, it bears restating that
both IHL and IHRL prohibit the use of sound and acoustic devices to
terrorize, torture or inflict inhuman or degrading treatment.69
In terms of governance and regulation, acoustic devices raise the
question of what constitutes an acceptable health risk and what the
standard of reference should be given their diverse applications in
military, law enforcement and private settings. In the military, where
noise exposure is a well-known problem, a number of impulse-noise
exposure criteria have been developed.70 ‘Safe exposure’ to
noise is sometimes given as a peak level of 162 dB,71 but a 2003
NATO research study was unable to propose a single measure or as-
sessment method to predict the auditory hazard for different impulse
noises and blasts.72
In relation to
sound, the World Health Organization con-
siders that exposure levels above 85 dB in an occupational setting
are ‘hazardous for workers’,73 and deems exposure to recreational
sound in excess of 85 dB for eight hours or 100 dB for 15 minutes
‘unsafe’.74 Although these standards aim to protect workers from
damage over years of exposure, in a Canadian case implicating an
LRAD, the judge considered that occupational health and safety legis-
lation served as a useful guide to determine restrictions on the use
of LRAD to prevent unsafe exposure which would amount to human
rights violations.75 In 2011, Canadian authorities defined minimum
distances at various levels for ‘urban scenarios’, and recommended
that the use of the alert function (i.e. use to emit a high-decibel, nar-
row-frequency sound wave rather than use as a powerful loudspeak-
er) ‘should be minimized’, that the devices ‘should not be operated
continuously’ and that any use should be followed by an equivalent
period of silence.76
In the same vein, Jürgen Altmann has proposed rules for safe
operation to prevent injury. He suggests technical measures to limit
the sound power of LRAD as a function of distance between the
device and the exposed population, and to limit the duration of use,
1 See, e.g., N. Broner, ‘The Effects of Low Frequency Noise on People – A Review’,
Journal of Sound and Vibration
resources/broner-n-effects-low-frequency-noise-people-review/. The work of Vladimir
Gavreau is often cited in this context (see, e.g., G. Vassilatos, ‘The Sonic Doom of
Vladimir Gavreau’, 52(4)
vol/52/n04/Vassilatos_on_Vladimir_Gavreau.html). His work has more recently been
described as ‘unscientific’ (J. H. Mühlhans, ‘Low Frequency and Infrasound: A Critical
Review of the Myths, Misbeliefs and Their Relevance to Music Perception Research’,
Musicae Scientiae
(September 2017) 272).
2 E. Labott et al, ‘US Embassy Employees in Cuba Possibly Subject to “Acoustic
Attack”’, CNN, 10 August 2017,
cuba-acoustic-attack-embassy/index.html. Cuba has denied any involvement, see
E. McKirdy et al, ‘Cuban president denies “sonic” attacks on US diplomats’, CNN, 17
September 2018,
3 E.g. R. E. Bartholomew, ‘Politics, Scapegoating and Mass Psychogenic Illness:
Claims of an “Acoustical Attack” in Cuba are Unsound’, 110(12)
Journal of the Royal
Society of Medicine
(2017); C. C. Muth and S. L. Lewis, ‘Neurological Symptoms
Among US Diplomats in Cuba’, 319(11) JAMA (20 March 2018). Researchers who
reverse-engineered a recording of what embassy staff heard concluded, however,
that ‘[i]f ultra-sound is to blame, then a likely cause was two ultra-sonic signals that
accidentally interfered with each other, creating an audible side effect’ (J. Kumagai,
‘Reverse Engineering the “Sonic Weapon”’, 55(3)
IEEE Spectrum
(March 2018), See also I. Sample, ‘Cuban
“Acoustic Attack” Report on US Diplomats Flawed, Say Neurologists’,
The Guardian
14 August 2018,
4 N. Davison,
‘Non-Lethal’ Weapons
, Palgrave Macmillan, 2009, p. 186.
5 J. Altmann, ‘Acoustic Weapons – A Prospective Assessment’, 9(3)
Science &
Global Security
(2001) 173,;
Mühlhans, ‘Low Frequency and Infrasound’, 270.
6 A NATO study notes: ‘A large variety of acoustic devices have been proposed
for non-lethal applications. Most are of uncertain ef fectiveness and many could
damage hearing.’ (North Atlantic Treaty Organization,
The Human Effects of Non-
Lethal Technologies
, RTO Technical Report, NATO doc AC/323(HFM-073)TP/65,
August 2006, p. G-4,
Reports/RTO-TR-HFM-073/$$TR-HFM-073-ALL.pdf.). See also J. R. Jauchem and M.
C. Cook, ‘High-Intensity Acoustics for Military Nonlethal Applications: A Lack of Useful
Systems’, 172(2)
Military Medicine
(2007) 186,
7 See in particular Altmann, ‘Acoustic Weapons’; Mühlhans, ‘Low Frequency and
8 See in particular D. P. Fidler, ‘The Meaning of Moscow: “Non-Lethal” Weapons
and International Law in the Early 21st Century’, 87(859)
International Review of
the Red Cross
(September 2005),
irrc_859_fidler.pdf; N. Lewer and N. Davison,
Bradford Non-Lethal Weapons Research
Research Report no. 7
, May 2005, https://bradscholars.brad.
9 J. E. K. Parker, ‘Towards an Acoustic Jurisprudence: Law and the Long Range
Acoustic Device’, 14(2)
Law, Culture and the Humanities
(2018) 209.
10 Steve Goodman speaks of a ‘creeping colonization of the not yet audible and
the infra- and ultrasonic dimensions of unsound’ (S. Goodman,
Sonic Warfare: Sound,
Affect, and the Ecology of Fear
, The MIT Press, 2010, p. xvi) and Juliette Volcler cites
SPIRAW’s ‘recherche des frontières que colonisent tranquillement les militaires et les
forces de police à travers l’usage d’armes soniques’ (J. Volcler, ‘Le son comme arme’,
Article XI
, February 2010, revised January 2011,
11 Most of the information about such devices comes from the US, which has
publicly reported more on its research and development in this area than most other
12 For an in-depth treatment of this issue, see Goodman,
Sonic Warfare
; J. M.
Daughtry, L
istening to War: Sound, Music, Trauma, and Survival in Wartime Iraq
, Oxford
University Press, 2015; N. Ramsey, ‘Listening to War: Sound and Noise in Romantic Era
Military Writing’, 5(2)
Republics of Letters
13 See in particular S. G. Cusick, ‘Music as Torture / Music as Weapon’,
Transcultural de Música
14 Well-documented instances include American troops blasting the Vatican’s
embassy in Panama City to dislodge Noriega in 1990 (A. Campoy, ‘The US Pursuit
of Panama’s Manuel Noriega Kicked Off a New Era of Music Torture’,
, 30 May
era-of-sound-as-psychological-warfare/); the FBI’s sonic assault in Waco in 1993 (V.
Madsen, ‘
Cantata of Fire: Son et Lumière
in Waco Texas, Auscultation for a Shadow
Play’, 14(1)
Organized Sound
(2009)); the sonic booms of Israeli fighter jets flying
at low altitude over Palestinian cities in 2005 (C. McGreal, ‘Palestinians Hit by Sonic
Boom Air Raids’,
The Guardian
, 3 November 2005,
world/2005/nov/03/israel); US jets over Nicaraguan cities in 1984 (International
Court of Justice,
Military and Paramilitary Activities in and Against Nicaragua
Nicaragua v United States of America
), Judgment (Merits), 27 June 1986, §§87, 91)
and the blasting of music during the US siege of Falluja in 2004 (J. Pieslak,
Targets: American Soldiers and Music in the Iraq War
, Indiana University Press, 2009,
p. 84). For more information on these phenomena, see Volcler, ‘Le son comme arme’;
Cusick, ‘Music as Torture / Music as Weapon’, Daughtry,
Listening to War
; Goodman,
Sonic Warfare
15 Davison,
‘Non-Lethal’ Weapons
, p. 186.
16 See J. Altmann,
Millimetre Waves, Lasers, Acoustics for Non-Lethal Weapons?
Physics Analyses and Inferences
, Deutsche Stiftung Friedensforschung, 2008, p. 44, (noting that ‘after almost
ten years of research, the [US Joint Non-Lethal Weapons Program] stopped funding
infrasound-weapon work for lack of “a reliable, repeatable bio-effect with sufficiently
high infrasound amplitude at a minimum specified range”’) and Jauchem and Cook,
‘High-Intensity Acoustics for Military Nonlethal Applications’, 186 (concluding that ‘[o]
n the basis of results of numerous investigators, it seems unlikely that high-intensity
acoustic energy in the audible, infrasonic, or low-frequency ranges will provide a device
suitable to be used as a nonlethal weapon’).
17 Mühlhans, ‘Low Frequency and Infrasound’, 269.
18 Altmann, ‘Acoustic Weapons’, 165.
19 The size and mass differ between infra- and ultrasound devices, but hand-held
acoustic weapons of pistol or rifle sizes with a range of tens of metres are highly
unlikely according to Altmann (Ibid., 199–200, 204).
20 Altmann,
Millimetre Waves, Lasers, Acoustics for Non-Lethal Weapons?
, p. 6.
21 E. Durr, ‘Training with High-Tech Hailer System on the Hudson’,
Guard Times
(Spring 2015), 43,
22 N. Lewer and N. Davison, ‘Non-Lethal Technologies – An Overview’, 1
Disarmament Forum
(2005) 41,
23 Business Wire, ‘American Technology Reports on Growing Long Range Acoustic
Devices – LRAD – Business’, 26 August 2004,
Range-Acoustic. Its precursors were, however, initially envisaged for civilian markets,
unrelated to the use of force. For more information, see Parker, ‘Towards an Acoustic
Jurisprudence’, 210–211.
24 A. Blenford, ‘Cruise Lines Turn to Sonic Weapon’,
BBC News
, 8 November 2005,
25 See, e.g., ACLU Pennsylvania, ‘City of Pittsburgh Settles G-20 Lawsuits’, 14
November 2012.
26 Parker, ‘Towards an Acoustic Jurisprudence’, 214,
27 Altmann,
Millimetre Waves, Lasers, Acoustics for Non-Lethal Weapons?
, p. 6.
28 See the manufacturer’s website:
29 Y. Katz, ‘Kalandiya: IDF Uses “Scream” Anti-Riot Device for 1st Time’, J
, 22 September 2011,
30 PDT Agro Ltd ‘Bird Control Solution’,; D. Hambling, ‘A Sonic
Blaster So Loud, It Could Be Deadly’,
, 18 January 2010, https://www.wired.
31 E.g. Amtech Less Lethal Systems, ‘ALS1208 Bore Thunder Muzzle Bang’,; Defense Technology,
‘12-Gauge Aerial Warning / Signaling Munition, 100 Meters’, http://www.defense-
32 For example, in 2014, a French protester died after being hit in the back by
a stun grenade (‘Sivens: des traces d’explosifs retrouvés sur les vêtements de Rémi
, 28 October 2014,
html). The use of these grenades was suspended shortly after the incident, and then
prohibited in 2017 (‘Plus de deux ans après la mort de Rémi Fraisse, les grenades
offensives de type F1 interdites’,
Le Monde/AFP
, 12 May 2017, https://www.lemonde.
les-grenades-offensives-de-type-f1-interdites_5126979_1653578.html). See also J.
Angwin and A. Nehring, ‘Hotter Than Lava’,
, 12 January 2015, https://www.; J. Volcler,
Extremely Loud: Sound as a Weapon
, The
New Press, 2013, pp. 59–61.
33 E-LABS Inc., Performance Characterization Study: Noise Flash Diversionary
Devices (NFDDs), Final Report, December 2003, p. 5,
34 D. Whitson and J. Clark, ‘Flash/Sound Diversionary Devices: A Comprehensive
The Tactical Edge
(Summer 2011) 18,
userfiles/pdfs/Whitson_SU_2011_1.pdf. See also W. A. Burgei et al, ‘Developing
Non-Lethal Weapons: The Human Effects Characterisation Process’,
Defense AT&L
(May-June 2015) 30-34,
35 E.g. A. Nakashima and R. Farinaccio, ‘Review of Weapon Noise Measurement
and Damage Risk Criteria:
Considerations for Auditory Protection and Performance’, 180(4)
Military Medicine
(2015) 402.
36 Compound Security Systems, ‘Anti-Loitering Devices’, https://www.
37 Compound Security Systems, ‘Mosquito MK4 (Anti-Loitering Device): Customise
Your Own Kit’,
38 For a recent study on physical and psychological effects of sound, see J. P.
The Effects of Sound on People
, Wiley, 2016.
39 Davison, ‘Non-Lethal’ Weapons, p. 186. Mühlhans notes that in relation to low
frequency, including infrasound, ‘the effects depend […] heavily on sound-pressure
levels and considerably less on frequency or the nature of sound.’ (Mühlhans, ‘Low
Frequency and Infrasound’, 268).
40 Altmann, ‘Acoustic Weapons’, 177.
41 Ibid., 174.
42 Davison,
‘Non-Lethal’ Weapons
, p. 186. See also Mühlhans, ‘Low Frequency and
Infrasound’, debunking several myths about infrasound.
43 Altmann, ‘Acoustic Weapons’, 186.
44 Davison,
Bradford Non-Lethal Weapons Research Project
Report no. 7
, p. 34.
45 For example, during the FBI’s Waco siege, it exposed 25 children, many of them
toddlers and infants, to the same sound campaign as adults. See, e.g., A. A. Stone
et al, ‘Report and Recommendations Concerning the Handling of Incidents Such as
the Branch Davidian Standoff in Waco Texas’, Submission to Deputy Attorney General
Philip Heymann, 10 November 1993, Frontline, Waco: The Inside Story, https://www.
46 Consider, however, Working Paper COLU/202 on fuel-air explosives, submitted by
Sweden in the 1970s, which proposed to prohibit ‘the anti-personnel use of weapons
which for their effects rely exclusively on shock waves in the air’. When confronted with
the criticism that this formulation would capture weapons other than fuel-air explosives,
‘e.g. concussion grenades’, the sponsor of the proposal responded that ‘there were
advantages in the use of forward-looking wording’ (ICRC,
Conference of Government
Experts on the Use of Certain Conventional Weapons (Second Session – Lugano 28.1.-
, Report, Geneva, 1976, §75).
47 See, e.g., J. Schrantz, ‘The Long Range Acoustic Device: Don’t Call It a Weapon
– Them’s Fightin’ Words’,
Army Lawyer
(August 2010) 53–59,
rr/frd/Military_Law/AL-2010.html; LRAD, ‘Fact Sheet’,
48 The US LRAD was reportedly exported to China (D. Hambling, ‘US “Sonic
Blasters” Sold to China’,
, 15 May 2008,
us-sonic-blaste/). On export control questions, see also Omega Research Foundation
and Amnesty International USA,
Submission in Response to BIS Request for
Public Comments on Crime Control License Requirements in EAR
, 17 June 2008,
pp. 7–8,
49 Altmann, citing R. Sævik, notes that the Norwegian military call it a weapon
Millimetre Waves, Lasers, Acoustics for Non-Lethal Weapons?
, p. 44).
Consider also a recent US ruling finding that the New York City Police Department
use of an LRAD for crowd control in 2014 constituted ‘excessive force’ (United States
Court of Appeals for the Second Circuit,
Edrei v Bratton
, Docket no. 17-2065, 13 June
2018). Similarly, under the Irish 1997 Non-Fatal Offences Against the Person Act, the
definition of ‘force’ in relation to the offence of assault includes the application of
‘noise’ (Art 2(2)).
50 NATO,
The Human Effects of Non-Lethal Technologies
, p. G-4.
51 Art 35(2), 1977 Additional Protocol I (API) to the Geneva Conventions; ICRC
Customary IHL Study, Rule 70.
52 Schrantz, ‘The Long Range Acoustic Device’, 58, citing a US Army legal review
memorandum of 2007, at which time several hundred LRAD had already been
53 J. P. Winthrop,
Preliminary Legal Review of Proposed Acoustic Energy Non-Lethal
Weapon Systems
, Department of the Navy, Office of the Judge Advocate General, 29
April 1998, pp. 8–9.
54 1995 Protocol on Blinding Laser Weapons (Protocol IV to the Convention on
Certain Conventional Weapons); ICRC Customary IHL Study, Rule 86.
55 S. Casey-Maslen,
Non-Kinetic-Energy Weapons Termed ‘Non-Lethal’: A
Preliminary Assessment Under International Humanitarian Law and International
Human Rights Law
, Geneva Academy of International Humanitarian Law and Human
Rights, October 2010,
files/Non-Kinetic-Energy%20Weapons.pdf; Altmann, ‘Acoustic Weapons’, 206.
56 Goodman,
Sonic Warfare
, p. 9. Parker reminds us that ‘[s]ound is experienced
by the entire body’ and ‘is profoundly haptic’ (Parker, ‘Towards an Acoustic
Jurisprudence’, 203).
57 Goodman recognizes ‘a tension between two critical tendencies tagged the
politics of noise and the politics of silence’ that constitute ‘the typical limits to a
politicized discussion of the sonic’ (Goodman,
Sonic Warfare
, pp. 17–20). Parker
notes that ‘[t]he LRAD’s sheer volume means that, irrespective of what is being said, it
will likely register affectively as a threat’ (Parker, ‘Towards an Acoustic Jurisprudence’,
58 Parker, ‘Towards an Acoustic Jurisprudence’, 206.
59 Art 51(4), API; ICRC Customary IHL Study, Rules 11 and 12.
60 A. Dymond-Bass and N. Corney, ‘The Use of “Less-Lethal” Weapons in Law
Enforcement’, S. Casey-Maslen (ed.),
Weapons and International Human Rights Law
Cambridge University Press, 2014, p. 42.
61 Altmann,
Millimetre Waves, Lasers, Acoustics for Non-Lethal Weapons?
, p. 49.
See also W. M. Arkin, ‘Acoustic Anti-Personnel Weapons: An Inhumane Future?’, 13(4)
Medicine, Conflict and Survival
(2007) 320.
62 A Canadian review of the LRAD100X and the LRAD300X notes that ‘within a
city setting the sound levels of the LRAD could be 3 to 6 dB higher than in an open
air environment’ (Ministry of Community Safety and Correctional Services,
Review of
Police Use of Long-Range Acoustic Devices
, p. 12,
63 Art 3, 1990 UN Basic Principles on the Use of Force and Firearms by Law
Enforcement Officials (BPUFF). Amnesty International has proposed guidelines for
the implementation of the BPUFF with specific recommendations regarding non-
lethal weapons testing and deployment and their use in crowd control (Amnesty
Use of Force: Guidelines for Implementation of the UN Basic Principles
on the Use of Force and Firearms by Law Enforcement Officials
, 2015, Chapters 6 and
64 In particular, flash-bang devices have attracted severe criticism and legal
challenges due to their capacity to cause severe injury and death. See, e.g., Angwin
and Nehring, ‘Hotter Than Lava’. On the right to health and non-lethal weapons
generally, see E. Hoffberger, ‘Non-Lethal Weapons: The Principle of Proportionality
in Armed Conflict and the Right to Health in Law Enforcement’, 38(2)
Zb. Prav. fak.
. Rij
. (2017) 844–847.
65 See, e.g., United States District Court for the Western District of Pennsylvania,
Karen L. Piper v. City of Pittsburgh et al
, Complaint, 21 September 2011. The case
involved an LRAD and was settled. See also
Edrei v Bratton
, ruling that the New
York City Police Department’s use of an LRAD for crowd control in 2014 constituted
‘excessive force’.
66 A German study warns that babies and young children are at particular risk
of being exposed to the device for dangerously long periods because the adults
accompanying them may not hear the sound and, thus, may not be able to protect
them (German Federal Institute for Occupational Safety and Health,
Einsatz von
Ultraschall-Störgeräusch-Sendern nicht ganz unbedenklich
, 14 December 2007,
67 The French Tribunal de Grande Instance de Saint-Brieuc characterized it as
an illegal sonic weapon (une ‘arme sonore illicite’). See ‘Le boîtier “antijeunes”
interdit par la justice’,
Le Monde
, 30 April 2008,
For more detail, see Volcler, ‘Le son comme arme’.
68 Volcler relates a ‘Kafkaesque exchange’ between people complaining about
discomfort caused by a Mosquito illegally installed by a bank in Ixelles, Belgium, and
police officers who can’t hear anything and don’t believe them (Volcler, ‘Le son comme
69 On ‘subjection to noise’ as a form of inhuman or degrading treatment, see, e.g.,
European Court of Human Rights,
Ireland v The United Kingdom
, App no. 5310/71,
Judgment, 18 January 1978. (On 20 March 2018, the Court dismissed (pending
request for referral to the Grand Chamber) an Irish request for revision of the judgment
to the effect that the use of ‘the five techniques of interrogation’ amounted to torture,
not merely inhuman and degrading treatment.) For a discussion of sound as torture,
see Cusick, ‘Music as Torture / Music as Weapon’.
70 See, e.g., G. Kerry and J. J. Bugge,
The NATO CCMS Working Group on Noise
from Weapons – An Overview
, inter.noise 2000, 29th International Congress and
Exhibition on Noise Control Engineering, 27–30 August 2000, Nice, France, www.
71 Altmann, ‘Acoustic Weapons’, 189.
72 NATO,
Reconsideration of the Effects of Impulse Noise
, RTO Technical Report TR-
017, NATO doc AC/323(HFM-022)TP/17, April 2003,
download?doi=; Nakashima and Farinaccio,
‘Review of Weapon Noise Measurement and Damage Risk Criteria’, 404.
73 World Health Organization, ‘Work-Related Noise’,
The World Health Report
Chapter 4,
74 World Health Organization, ‘1.1 Billion People at Risk of Hearing Loss’, Press
75 See Parker, ‘Towards an Acoustic Jurisprudence’, 213–214.
76 The distance limits represent ‘distances at which a sound level of 100 dBA
[A-weighted decibels] would not be expected to be exceeded under the worst case
conditions (full volume control setting, reflective ground surface, receptor located on
the axis of the device at a location near a building) in the urban scenarios. Fifteen
minutes of unprotected continuous exposure to 100 dBA corresponds to an equivalent
sound exposure level over 8 hours […] of 85 dBA.’ (Ministry of Community Safety
and Correctional Services,
Review of Police Use of Long-Range Acoustic Devices
, pp.
77 Altmann,
Millimetre Waves, Lasers, Acoustics for Non-Lethal Weapons?
, p. 52.
According to Altmann, to prevent permanent hearing damage from an LRAD, ‘the
warning tone must not be used closer than 5 m. The exposure duration has to be
kept at a few seconds out to 50 m. Time limitations are needed to more than 100 m
distance.’ (p. 50)
78 Amnesty International and Omega Research Foundation,
The Human Rights
Impact of Less Lethal Weapons and Other Law Enforcement Equipment
, 2015, p.
79 N. Corney,
Less Lethal Systems and the Appropriate use of Force, Omega
Research Foundation,
2011.pdf; Amnesty International,
Use of Force
ResearchGate has not been able to resolve any citations for this publication.
Full-text available
At the intersection of new weapon technologies and international humanitarian law, so-called “non-lethal” weapons have become an area of particular interest. This article analyses the relationship between “non-lethal” weapons and international law in the early 21st century by focusing on the most seminal incident to date in the short history of the “non-lethal” weapons debate, the use of an incapacitating chemical to end a terrorist attack on a Moscow theatre in October 2002. This tragic incident has shown that rapid technological change will continue to stress international law on the development and use of weaponry but in ways more politically charged, legally complicated and ethically challenging than the application of international humanitarian law in the past.
This article argues for a shift in how we relate to legal thought, practice and experience. It argues for a specifically acoustic jurisprudence, an orientation towards law attuned to questions of sound and listening. The argument is made in the abstract before moving on to an example intended to establish the political stakes of the intervention. My example is the Long Range Acoustic Device, invented at the turn of the century and used increasingly today by military and police forces as a way of amplifying the authority of the state and, in some instances, enacting serious acoustic violence.
Better stunned than gunned. Slogan by American electric-shock manufacturer Nova Technologies USA. Introduction. Contemporary police officers are increasingly equipped with a wide range of ‘less-lethal’ weapons. Some weapons, such as batons or pepper spray, are issued to a large number of officers. Others, such as projectile electric shock weapons or ‘less-lethal’ launchers, are often, but not always, restricted to a smaller group of specially trained officers. While debate often focuses on police use of firearms, ‘less-lethal’ weapons can have serious – and sometimes lethal – outcomes, and individuals are far more likely to be subjected to, or to witness, their use. As the quotation above suggests, such ‘less-lethal’ weapons are often marketed as having a positive human rights impact, insofar as they decrease the need for the use of firearms. But police use of ‘less-lethal’ weapons can still constitute a violation of the right to life or to freedom from torture and ill-treatment and, more generally, negatively influence public perception of the police. Some ‘less-lethal’ weapons increase the overall use of force (for example, when used in situations that could, and should, have been resolved through non-violent or less violent means) while potentially reducing police officers’ safety and security (for example, by putting an officer at risk when weaponry fails to function as expected).
Noise-induced hearing loss resulting from weapon noise exposure has been studied for decades. A summary of recent work in weapon noise signal analysis, current knowledge of hearing damage risk criteria, and auditory performance in impulse noise is presented. Most of the currently used damage risk criteria are based on data that cannot be replicated or verified. There is a need to address the effects of combined noise exposures, from similar or different weapons and continuous background noise, in future noise exposure regulations. Advancements in hearing protection technology have expanded the options available to soldiers. Individual selection of hearing protection devices that are best suited to the type of exposure, the auditory task requirements, and hearing status of the user could help to facilitate their use. However, hearing protection devices affect auditory performance, which in turn affects situational awareness in the field. This includes communication capability and the localization and identification of threats. Laboratory training using high-fidelity weapon noise recordings has the potential to improve the auditory performance of soldiers in the field, providing a low-cost tool to enhance readiness for combat. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.
Acoustic weapons are under research and development in a few countries. Advertised as one type of non‐lethal weapon, they are said to immediately incapacitate opponents while avoiding permanent physical damage. Reliable information on specifications or effects is scarce, however. The present article sets out to provide basic information in several areas: effects of large‐amplitude sound on humans, potential high‐power sources, and propagation of strong sound.Concerning the first area, it turns out that infrasound ‐ prominent in journalistic articles ‐ does not have the alleged drastic effects on humans. At audio frequencies, annoyance, discomfort and pain are the consequence of increasing sound pressure levels. Temporary worsening of hearing may turn into permanent hearing losses depending on level, frequency, duration etc.; at very high sound levels, even one or a few short exposures can render a person partially or fully deaf. Ear protection, however, can be quite efficient in preventing these effects. Beyond hearing, some disturbance of the equilibrium, and intolerable sensations mainly in the chest can occur. Blast waves from explosions with their much higher overpressure at close range can damage other organs, at first the lungs, with up to lethal consequences.For strong sound sources, mainly sirens and whistles can be used. Powered, e.g., by combustion engines, these can produce tens of kilowatts of acoustic power at low frequencies, and kilowatts at high frequencies. Using explosions, up to megawatt power would be possible. For directed use the size of the sources needs to be on the order of 1 meter, and the required power supplies etc. have similar sizes.Propagating strong sound to some distance is difficult, however. At low frequencies, diffraction provides spherical spreading of energy, preventing a directed beam. At high frequencies, where a beam is possible, non‐linear processes deform sound waves to a shocked, saw‐tooth form, with unusually high propagation losses if the sound pressure is as high as required for marked effects on humans. Achieving sound levels which would produce aural pain, equilibrium problems, or other profound effects seems unachievable at ranges above about 50 m for meter‐size sources. Inside buildings, the situation is different, especially if resonances can be exploited.Acoustic weapons would have much less drastic consequences than the recently banned blinding laser weapons. On the other hand, there is a greater potential of indiscriminate effects due to beam spreading. Because in many situations acoustic weapons would not offer radically improved options for military or police, in particular if opponents use ear protection, there may be a chance for preventive limits. Since acoustic weapons could come in many forms for different applications, and because blast weapons are widely used, such limits would have to be graduated and detailed.
hilst the focus for this issue of Disarmament Forum is on chemical and biological weapons, sight should not be lost of the spectrum of non-lethal technologies that are being deployed or under development. These technologies will have an increasing impact on war fighting, peace support operations, civil policing and prison control. It is our purpose here to briefly review the non-lethal field so that biochemical incapacitating agents can be placed in a broader context. There is an extensive literature associated with non-lethal weapons, and readers are directed to this for more detailed information and discussion.1 We will only highlight the key characteristics and concerns associated with these non-lethal technologies. There has been a growing interest in non-lethal weapons over the last decade. It has been argued, and in some cases operationally demonstrated, that non-lethal technologies are particularly useful in conflict situations such as when combatants and non-combatants are mixed together (sometimes deliberately); when there is a requirement for alternatives to lethal methods in military peace support operations; when civil law enforcement agencies and prison services have to manage violent lawbreakers; and for riot control. There has also been increasing pressure to develop methods of being able to fight a "bloodless and humane" war, and increasing resistance by domestic constituencies to accept deaths in war operations. Advances in non-lethal technology have been made possible by additional investment both by governments and private companies, and the fact that many of the technologies have dual-use military/civilian applications. Other factors that have fuelled this attention to non-lethal weapons have been debates concerning the revolution in military affairs and the revolution in military technology. Some analysts have argued that the term "non-lethal" is a misnomer, and that "less lethal" is a more appropriate and accurate description of the weapons described in this paper. We would agree, of course, that there is no guarantee that any weapon can be 100% non-lethal. But we think that the label "non-lethal" has a useful generic function and that the criteria laid out in our following definition clearly set the parameters to what we would call a non-lethal weapon. Non-lethal weapons are specifically designed to incapacitate people or disable equipment, with minimal collateral damage to buildings and the environment; they should be discriminate and not cause unnecessary suffering; their effects should be temporary and reversible; and they should provide alternatives to, or raise the threshold for, use of lethal force. Existing non-lethal weapons include rubber and plastic bullets, entangling nets, irritant sprays such as pepper or tear gas, and electrical stunning devices such as the "Taser" gun. New non-
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.