The psychoacoustic effect of infrasonic, sonic and ultrasonic frequencies within non-lethal military warfare techniques.
Exploring the use of audio to influence humans physically and psychologically as a means of non-lethal warfare methods throughout both the 20th and the 21st century.
Originally published by Ryan Littlefield (http://Littlefield.co) and the University of Portsmouth.
The term ‘infrasound’ defines itself as the inaudible frequency range below the human bandwidth of around 20Hz. When discussing infrasound, it’s often associated with acts of nature, sources such as the Fuego volcano in Guatemala emitted 120 decibels of infrasonic sound ranging around 10Hz (Georgia State University, no date). It is with occurrences like this that calls for a large amount of infrasonic monitoring to counter natural disaster detection. Beyond the use of infrasound detection, this frequency range, of which is inaudible to us, has been researched throughout the decades to investigate it’s effects on the human body. One of which is it’s application to military usage.
Throughout the 20th and 21st century, there has been a vast amount of research collected and interest gained in the use of non-lethal weapons (NLW), which are intended to immobilise or impair targets without causing permanent or severe damage to the human body. As technologies have developed, it’s apparent that military bodies within the world seek to create weapons resulting in “war’s without death” (Scott & Monitor, 2010). However, it is within the creation of new weapons that many issues arise, which perhaps may be a reason there is little evidence for the deployment of NLW. It’s apparent that some concepts of using infrasound may violate disarmament treaties, for example, the 1999 European Committee stated:
“global ban on all research and development, whether military or civilian, which seeks to apply knowledge of the chemical, electrical, sound vibration or other functioning of the human brain to the development of human beings, including a ban on actual or possible deployment of such systems” (Giordano, 2014).
Thus, this may result in military bodies taking a critical view before the acceptance of research to be made. However, it is important to understand at this point within this study, that this does not just encompass infrasonic sound but also applies to ultrasonic sound too.
Despite this, it is the alleged properties that infrasound, when applied correctly to humans, that have allowed for the field to be of interest within military application. Within Table 1 we can see a notable number of applications that infrasound could possibly or has been applied for:
Infrasound has resulted in a large amount of interest within the creation of NLW. It is apparent that given the technical depth that infrasound can be applied to within weaponry, a very in depth analysis of each device would be required. The present chapter within this text will analyse research collated that will allow for a greater insight into the application of infrasound on the human body, thus allowing us to formulate a background before exploring the outcome of the research tested within this study.
Physical and Psychological Effects
Infrasound has been utilised as a means of sonic warfare for physical human impact, dating back to World War 1. Acoustic imaging was the primitive use of infrasonic sound during World War 2, for the use of radar and sonar techniques in order to detect locations of enemy artillery (Ihde, 2015). Despite there bing many references to acoustic weaponry, as early as World War 2, it is in the 1960’s that actual documented research becomes more available. As described in, Secret Weapons of the Third Reich (E. Simon, 1971), one such device is discussed:
“…design consisted of a parabolic reflector, 3.2 meters in diameter, having a short tube which was the combustion chamber or sound generator, extending to the rear from the vertex of the parabola. The chamber was fed at the rear by two coaxial nozzles, the outer nozzle emitting methane, and the central nozzle oxygen. The length of the chamber was one- quarter the wavelength of the sound in air. Upon initiation, the first shock wave was reflected back from the openend of the chamber and initiated the second explosion. The frequency was from 800 to 1500 impulses per second. The main lobe of the sound intensity pattern had a 65 degree angle of opening, and at 60 meters’ distance on the axis a pressure of 1000 microbars had been measured. No physiological experiments were conducted, but it was estimated that at such a pressure it would take from 30 to 40 seconds to kill a man. At greater ranges, perhaps up to 300 meters, the effect, although not lethal, would be very painful and would probably disable a man for an appreciable length of time. Vision would be affected, and low- level exposures would cause point sources of light to appear as lines.”
This device, known as the ‘Wirbelwind Kanonew’ , is perhaps the only known fully developed infrasonic weapon created in order to physically effect it’s target, with the intention of countering enemy aircraft and infantry by creating a vortex of sound (Crab, 2008). Moreover, there are cases that perhaps suggest a possible application of infrasound to cause physical damage to the ear drum. (Harding, Bohne, Lee, & Salt, 2007) cites that frequency ranges around 4Hz, at high decibels, are perhaps able damage parts of the ear drum. The vibrational movement created by the infrasonic frequency result in large fluid movements of cochlear fluid, the intermixing of cochlear fluid is hypothesised to result in lasting damage. There are however, in contrary to this, studies also suggest the mechanisms of the ear have a normal reaction to infrasonic sound. As preciously mentioned, the central mechanism of the ear is the cochlear; within the cochlear there are two sensory cells, the inner hair cells (IHC) and the outer hair cells (OHC) (Cook, 1999). IHC responses are dependant on velocity and due to the fluid within the ear, the stimulus lowers as the frequency lowers; in contrast, OHC have a greater response to low frequency ranges such as infrasound. As a result, the effect of infrasound on IHC’s within the ear, could be suggested as inefficient thus resulting in infrasound’s effect on the ear, physically, being normal (Salt & Hullar, 2010). However, this does not suggest that the effect of infrasound on both IHC and OHC do not have a psychological effect on the brain. Exposure to levels above 80db between 0.5Hz and 10Hz causing these possible vibrational movements within the ear’s functions, are said to cause psychological changes such as fear, sorrow, depression, anxiety, nausea, chest pressure and hallucinations (ECRIP, 2008). It is the result of this effect in the middle ear, that (Goodman, 2010 p. 18) cites as being discovered by military personnel during World War 1 and World War 2.
The effect of emotional and psychological change as a result of infrasonic exposure can later be found during the second Indochina war. In 1973, The United States deployed the Urban Funk Campaign, a psychoacoustic attack during the war with the intention of altering mental states of their enemies (Goodman, 2010). The device utilised both infrasonic and ultrasonic frequencies, which emitted high decibel oscillations from a mounted helicopter onto the Vietnamese ground troops (Toffler, Alvin, & Toffler, 1995). Though there is no record of the specification of this device, one can assume that the U.S Military had tested the infrasonic frequency ranges in order to achieve a psychological effect on it’s targets. As previously cited by (Goodman, 2010), it is documented that the frequency range of 7Hz is thought to instil effects of uneasiness, anxiety, fear and anger. (Walonick, 1990) reports in a experiment that below 8Hz had caused agitation and uneasiness for participants. Goodman also supports this discussing “It has been noted that certain infrasonic frequencies plug straight into the algorithms of the brain and nervous system. Frequencies of 7 hertz, for example, coincide with theta rhythms, thought to induce moods of fear and anger.” (Goodman, 2010). It is within the psychological change that we begin to question the reasoning behind it, many of the studies in the next chapter of this study suggest that resonance is perhaps the reason as to why there could be an emotional and psychological change to human’s when exposed to infrasonic frequencies.
All objects have a property known as their resonant frequency, this involves the “re- enforcement of vibrations of a receiving system due to a similarity to the frequencies of the source” (Pellegrino & Productions, 1996). It is this property that is held within all matter, that we can apply sound as a means of resonance within the human body. It is resonance within the human body that is thought to create the psychological effects of that mentioned in the previous chapter.
Limited literature within the infrasonic frequency range allows for an array of research speculating conspiracies within the utilisation of infrasonic frequency ranges as a means of non-lethal weaponry and crowd control. As a result, this could lead to a plausible suggestion that military application of non-lethal audio weapons have not been made publicly available. A large influence on the development and notable usages of infrasonic frequencies as a means of deterrence, was the development of a low-frequency acoustic device by French scientist Vladimir Gavreau (Lothes, 2004). It is reported that Gavreau had discovered the infrasound weapon by result of a resonant frequency being emitted from a motor-driven ventilator within his office (Vassilatos, no date). Following this, Gavreau developed a device that emitted infrasonic sine wave frequencies around 7hertz, with military application, (Vassilatos, no date) said to induce painful symptoms effecting his laboratory staff with immediate effect, other results are reported of the likes of the feeling of fear and flight. Following this discovery Gavreau made discussions that highlighted the effect of infrasonic frequencies to humans, citing it as a possible cause of city dwellers’ stress (Broner, 2003). Gavreau’s discovery within this field has been largely researched and discussed throughout the acoustic warfare field. Vinokur, drew from Gavreau’s invention stating within his publication The Case of the Mythical Beast. (Vinokur, 1993)
“. . . sound with a frequency of less than 16 Hz is inaudible. It’s called infrasound, and its effect on human beings is not completely understood. We do know, however, that high- intensity infrasound causes headache, fatigue, and anxiety . . . Our internal organs (heart, liver, stomach, kidneys) are attached to the bones by elastic connective tissue, and at low frequencies may be considered simple oscillators. The natural frequencies of most of them are below 12 Hz (which is in the infrasonic range). Thus, the organs may resonate. Of course, the amplitude of any resonance vibrations depends significantly on damping, which transforms mechanical energy into thermal energy . . . this amplitude decreases as the damping increases. Also, the amplitude is proportional to the amplitude of the harmonic force causing the vibrations . . .”
It is also apparent that such frequencies have been used in many varying fields to provide evidence of it’s existence, exterior to military and police usage. Furthermore, British physiology researchers O’Keeffe & Angliss conducted an experiment to test the effects of infrasonic frequencies on the human brain in 2003. The method was conducted by playing 4 musical pieces to 700 participants two of which had 17hertz frequencies played unknowingly to the participants during the piece. Results found that 22% of the participants experienced a feeling of anxiety and fear (Stathatos, no date). A similar experiment entitled ‘The Haunt Project’ conducted by the Anomalistic Psychology Research Unit of Goldsmiths College, London, subjected 79 volunteers to a varying array of infrasonic frequencies. The primary analysis of the study cites that “63 (79.7%) of the participants felt dizzy or odd, 9 (11.4%) experienced sadness, 7 (8.9%) experienced terror” (French, Haque, Bunton- Stasyshyn, & Davis, 2009). It’s not unreasonable to state that within a varying amount of research conducted in this field, there is little evidence to suggest why infrasound actually has an effect on human emotion. Acoustic scientists investigating the result of noise pollution on workers determine that every organ within the human body has a resonant frequency and it’s own ‘acoustic properties’, this effect is discussed as a possible means as to why frequency has an effect on the human body (Prashanth & Venugopalachar, 2010). Additionally to this, Mahindra states that the resonant frequency of the eyeball has a direct effect on emotional states of anxiety & stress (Prashanth & Venugopalachar, 2010). (Braithwaite, 2006), who also have researched infrasonic resonance, cite that the change to fearful emotions may be a direct response to infrasound inducing resonance within the human eyeball. To support this statement, it’s also apparent within research conducted by NASA (Aerospace Medical Research Laboratory, 1976) that the resonant frequency of the human eyeball sits at around 18hertz, just below the audible range of the human ear. Referring back to the use of 7Hz frequency, additional support is gathered with many texts referring to resonant frequencies within the body, with the likes of (Broner, 2003) stating “…it has also been alleged that this is the resonant frequency of the body’s organs…”. One could perhaps draw a conclusion that resonance could be the catalyst for psychological change when exposed to infrasonic sound. The result of resonant frequencies within the body allow for a direct correspondence to the frequency rhythms within the brain, which cohere with the emotional state of every human. (Davies & Honours, no date) cites that “Many of the most profound effects of sound are attributed to infrasound in the region of 7Hz. This corresponds with the median alpha-rhythm frequencies of the brain.”. In addition to this, we also see discussed by (Sargeant, 2001):
“The frequency that is thought to be most dangerous to humans is between 7 and 8Hz. This is the resonant frequency of flesh and, theoretically, it can rupture internal organs if loud enough. Seven hertz is also the average frequency of the brain’s alpha rhythms; thus this frequency has been described as dangerous but also relaxing. Whether exposure to such infrasound can trigger epileptic seizures, as some fear, remains unclear; experimental data on exposure to such frequencies gives a variety of results. It should be noted, however, that the strobe light effect associated with triggering epileptic seizures flashes at an equivalent rhythm. Frequencies below 50Hz commonly lose their coherence and are perceived to pulse or fluctuate, which is analogous to the strobing beat of a modulated light.”
It is apparent that the frequency range sitting around 7Hz has been widely discussed as changing a subject emotional state when exposed. As a result of this research, the study will gather primary research to understand the effect of 7Hz on the human body, and analyse the emotional effect it has within formulated within this study.
The frequency that forms our own perception of sound sits between 20Hz — 20,000Hz, though only constituting a small amount of frequency spectrum, our auditory range can play an important role on our body; such as our equilibrioception (balance), proprioception and kinaesthesia (joint motion and acceleration), time, nociception (pain), magnetoception (direction), and thermoception (temperature differences) (HEYS, 2011). In order to full understand how the military application of sound can impact subjects psychologically, we must first understand how sound effects us mentally. Drawing from research collated pioneers within the sound-emotion connection, (Berlyne, 1971), (Meyer & Meyer, 1961), (Juslin & Sloboda, 2001) & (Liljeström, 2011) suggest six main mechanisms that happen when we perceive sound:
- Brain Stem Reflex is the effect of the brain recognising the acoustic properties of a sound, signalling the brain to react instinctively. Much similar to that of the American ‘Long Range Acoustic Device’ discussed later within this section.
- Evaluative conditioning is the effect of association between setting and sound; if the brain has heard a specific sound repeatedly in a specific setting, this triggers an emotional connection between the two.
- Emotional contagion is the perception of emotion expressed in certain sounds, whether or not the audio sounds sad, the association is recognised by the brain as an expression of emotion.
- Visual imagery relates to the brains association between a certain sound and a visual image or sensation.
- Episodic memory is the effect of the brain recognising sound as a memory, evoking the thought of stations to which a memory of sound was present.
- Sound expectancy is the brains mechanism of expecting how a sound will hear through previous experience.
- It is these mechanisms within the brain that aid us to draw the association between techniques developed for military application and sound in order to alter the state of mind of subjects. Whether it is by creating resonance within the brain or allowing for association between a sound and setting, many key pieces of research provide insight into the use of these techniques. It is with these mechanisms that we can gain an understanding as to why audible sound can effect our mental state.
The use of sound within our auditory range has been used to effect targets negatively from the mid-1900s. After analysing previously explored research within this field, a large amount of research refers to the United State’s military and their Psychological Operations Units (PsyOps) (United States Military, 1996). In many cases, we see the application of sound utilised in order to effect the six mechanisms discussed in chapter 3.2, allowing them to apply the use of sound for non-lethal warfare. As early as World War 2, we see strong evidence for the the deployment of sound, used in order to effect the psychology of enemies. The U.S militaries 23rd Special Troops, often referred to as the ‘Ghost Army’ were a troop of sound and radio engineers assigned to fabricate the sounds of marching troops, tanks, landing crafts allowing for sonic deception of their enemies (Goodman, 2009, p. 41). This perhaps was a result of that described in Philip Gerard’s book Secret Soldiers: How a Troupe of American Artists, Designers and Sonic Wizards Won World War II’s Battles of Deception Against the Germans:
“…screaming whine caused by a siren deliberately designed into the aircraft…it instilled a paralysing panic in those on the ground…For Division 17 of the National Research Defence Committee, the lesson was clear: sound could terrify soldiers…So they decided to take the concept to the next level and develop a sonic ‘bomb’…The idea of a sonic ‘bomb’ never quite panned out, so the engineers shifted their work toward battlefield deception.” (Gerard, 2002)
It is these tactics and technologies used within the early years of the military’s application of sound that allow for a greater insight into their usages. We also see many deployments of sonic frequencies, used in order to impact subjects negatively in varied military approaches such as interrogation, crowd control and creating fear against enemies. (BBC, 2003) cites the U.S’s PsyOps use of heavy metal and children’s music as a means of interrogation during warfare. Sergeant Mark Hadsell of PsyOps states “If you play it for 24 hours, your brain and body functions start to slide, your train of thought slows down and your will is broken. That’s when we come in and talk to them.” (BBC, 2003). However, though it is well documented that music and sound has been used within interrogation scenarios, this perhaps does not allow us to have an understanding of how sound effects our brain, as one can associate it’s effect as more physiological, due to sensory depravation caused, as a pose to psychological change. Psychological change, can infect be seen within the second Indochina war, similar to operations such as the Urban Funk Campaign discussed in section 3.1. Known as the “Wandering Soul” PsyOps units within the war attempted to exploit emotional contagion, evaluative conditioning and visual imagery of the enemy. John Pilger describes this within his book Heroes when discussing a PsyOps Officer in Vietnam:
“His favourite tape was called “Wandering Soul,” and as we lifted out of Snuffy he explained, “what we’re doing today is psyching out the enemy. And that’s where Wandering Soul comes in. Now you’ve got to understand the Vietnamese way of life to realise the power behind Wandering Soul. You see, the Vietnamese people worship their ancestors and they take a lot of notice of the spirits and stuff like that. Well, what we’re going to do here is broadcast the voices of the ancestors — you know, ghosts which we’ve simulated in our studios. These ghosts, these ancestors, are going to tell the Vietcong to stop messing with the people’s right to live freely, or the people are going to disown them.” The helicopter dropped to within twenty feet of the trees. The PsyOps captain threw a switch and a voice reverberated from two loudspeakers attached to the machine- gun mounting. While the voice hissed and hooted, a sergeant hurled out handfuls of leaflets which made the same threats in writing.” (Pilger, 1986).
These techniques have allowed for a greater amount of research in the 21st century, and as a common theme, this is particularly within the U.S military. In February 2004, the American Technology Corporation secured a $1 million contract to provide U.S forces in Iraq with Long Range Acoustic Devices (LRAD) (Goodman, 2009, p. 21). The LRAD focuses a directional 15° to 30° beam of sound between 1kHz and 5kHz reaching a distance of around 5,500 meters (LRAD , 2015). The use of the LRAD has been seen as a means of crowd control and has been identified in scenarios such as repelling pirates in Somalia and suicide bombers in the middle east (Goodman, 2009). It is the LRAD’s highly directional and high decibel sound that perhaps allows us to see the effect of the Brain Stem Reflex discussed in section 3.1. The impact of such a high decibel frequency could perhaps be believed to instil a natural instinctive flight mechanism in the brain; it is also document that the effect of the LRAD can cause nausea or dizziness, Amy Teibel writes, when discussing the Israeli use of a similar LRAD device
“A young Palestinian covers his ears from a sound, launched by a new weapon of the Israeli army, during a demonstration against the construction of Israel’s separation barrier at the West Bank village of Bil’in Friday, June 3, 2005. Israel is considering using an unusual new weapon against Jewish settlers who resist this summer’s Gaza Strip evacuation, a device that emits penetrating bursts of sound that send targets reeling with dizziness and nausea.” (Teibel, 2005).
However, when discussing the LRAD device we must also consider it’s use of ultrasound, as this device also applies ultrasound within it’s mechanism — this will be discussed in section 4.3.1. It is clear to see that the effect of sonic weapons used in order to impact the human body physiologically and alter the subjects mental state, is of large importance when researching acoustic warfare weapons.
The effect of sound on our brain often leads back to a common theme of resonance. Brainwave entrainment (or often referred to as neural entrainment) defines itself as the use of certain frequencies to activate bands of electrical wave resonance within our brain, to induce neurological states within our body. The preliminary proof of concept and main body of contextual research in this field stems from German professor of Physics, Heinrich Wilhelm Dove, who made discoveries in brainwave entrainment (BWE) through infrasonic frequencies entitled “Binaural beats” in 1841 (Kliempt, Ruta, Ogston, Landeck, & Martay, 1999). This method of entrainment occurs when two coherent frequencies within our audible range, are made present in both the left and right ear. Each frequency enters the auditory canal of the ear through to the cochlea; in turn the basilar membrane resonates at the frequency heard, this passes to the brain allowing us to recognise the frequency (Cook, 1999). The effect of this allows the brain to detect the phase difference between the two frequencies, rather than the brain responding to each frequency, the effect comprises of the difference between the two. This instils the ‘third’ frequency to resonate at an infrasonic range below 20–30Hz. The stimulus frequency reverberated by this induces a specific cerebral wave corresponding to characterised states of mind. (Caterina Filimon, n.d). Goodman states “…resonating with alpha and theta rhythms in the brain known to produce moods of fear, anxiety or anger” (Goodman, 2009, p. 18).
This technique has been applied to many non-warfare scenarios, which allows us to understand the importance of it’s application. Many musicians and directors have found ways of utilising neural entrainment to initiate fear into the listeners. Movie Director Gaspar Noe and musician Thomas Bangalter, used two differing bandwidths to instil beta wave frequency to the audience in order to create a feeling of tension in particular scenes of the movie Irreversible (Stathatos, no date).
Articles posted in The Times & New Scientist in 1973 document the use of a device called a ‘Squawk Box’ (New Scientist, 1973), used by the British Military in Northern Ireland. The device, mounted on a vehicle, emitted two frequencies of marginal difference in order to resonate a particular frequency bandwidth, similar to the effect discussed previously (Spannered, 2009). The article in New Scientist reports that the audio produced psychoacoustic effects giddiness, nausea, fainting, or merely a “spooky” psychological effect to targets. It also goes on to say that “Most people are intensely annoyed by the device and have a compelling wish to be somewhere else.” (New Scientist, 1973). Though the exact frequency range that was created is discussed in many aspects of military application, it’s important to draw from research to discover which areas of brainwave entrainment may perhaps effect the human body negatively.
Contrary to that described previously, the use of binaural beats has been actively discussed as a means of stress relief for participants, with research such as that collated by (Huang & Charyton, 2008) citing “People suffering from cognitive functioning deficits, stress, pain, headache/migraines, PMS, and behavioural problems benefited from BWE. However, more controlled trials are needed to test additional protocols with outcomes.” It is in review of physiological effects of brainwave entrainment we see in many pieces of research and literature such as that by, (Wahbeh, Calabrese, & Zwickey, 2007) & (Huang & Charyton, 2008), that confirm increased Serotonin levels within the body due to brainwave entrainment. With research such as (Mercola, 2015), discussing the role of increased Serotonin levels positively effecting the feeling of anxiety, that perhaps one may see the benefits of BWE. However, it is in fact discussed by (L. Fannin, Ph.D, no date) that the effect of BWE on frequency ranges that are already heightened within our brain is what causes a negative effect. Jeffrey L. Fannin, Ph.D, discusses:
“Anxiety — Too much beta activity may cause you to feel afraid or have thoughts of fear towards things that you are usually calm. I would imagine that if your brainwaves get high enough in the beta range, you will begin to notice a fear of things that are not normal to freak out over.
Stress — Though there are many good things that come with beta waves, there is also a huge possibility that they may stress you out. They are linked to increased stress, which is why it is important to learn how to shift your brainwaves when needed.
Paranoia — Paranoid schizophrenics are actually able to generate much more high beta (25–30Hz) activity than the average population. Are beta brainwaves the cause of schizophrenia? No, they are a side-effect and schizophrenia is a much more complex disease. Increasing beta brainwaves will not increase the likelihood of you becoming crazy, but they could make you feel more paranoid than usual.”
The spectrum beyond human audible range defines itself as ultrasound, this being above 20,000Hz. Ultrasound maintains very directional wave forms, due to their smaller wavelength and is very easily absorbed by materials, which allows for a greater application of use than other frequency bandwidths (Carovac, Smajlovic, & Junuzovic, 2011). Due to this, we can see ultrasound utilised in largely in the medical industry, with a particular focus on digital diagnostic imaging. Diagnostic imaging of ultrasound scanners operate around 2 to 18 megahertz, being hundreds of times greater than human perception (Carovac, Smajlovic, & Junuzovic, 2011). The mechanisms for this process depends on the echo time or Doppler shift, of the reflected ultrasonic sound on the internal organs or soft tissue, thus resulting in a 2d or 3d image (Georgia State University, no date). Ultrasonic sound is often produced using either piezoelectric or magnetostrictive transistors, by applying the output of an electronic oscillation within the device (Georgia State University, no date). The preliminary applications of ultrasound can be seen as a means of radar detection, similar to that of infrasound discussed in section 3.1, with the employment of submarine detectors in World War 1 (Carovac, Smajlovic, & Junuzovic, 2011). This depended on similar technologies of that used today in the medical industry, however since then, we have seen research within ultrasonic frequencies rise in many differing fields. Though it is apparent that the use of ultrasound has not been as widely investigated as both the infrasonic and sonic frequency fields, we can still see a common interest in it’s application for military use.
‘Hypersonic sound’ can be referred to simply as the focusing of ultrasound. Similar to that of light being focused into a laser, hypersonic sound works under a similar principle, with a speaker being focused into a highly directional focused beam of sound. The effect of this involves a speaker which emits low level ultrasound at around 100,000 vibrations per second, resulting in the audio creating the sound in the air as it travels, as a pose to regular speakers which make the sound waves on the face of the speaker (Norris, 2004). However, as previously mentioned in section 3.2.2, hypersonic sound used in devices like the LRAD do in fact utilise audible frequencies too and it is important to understand the cohesion within it’s application.
The military usage of hypersonic ultrasound is perhaps a technical advancement of the acoustic deception techniques used in World War II by the ‘Ghost Army’ and that of the Urban Funk Campaign in Vietnam both discussed in section 3.2.2. However, what these to techniques did not allow for was the development ultrasound, resulting in the audio being highly directional. Woody Norris, who would later found the LRAD Corporation, discussed the military application of ultrasound on a hypersonic sound lecture in 2004. Stating that the device had been deployed by the U.S military for use within Iraq, in order to deceive the enemy by creating the sound ‘fake’ troops. Moreover, he also discussed the use of the device that altered temperature of enemies whilst also stating:
“We make a version with this which puts out 155 decibels. Pain is 120. So it allows you to go nearly a mile away and communicate with people, and there can be a public beach just off to the side, and they don’t even know it’s turned on. We sell those to the military presently for about 70,000 dollars, and they’re buying them as fast as we can make them.” (Norris, 2004).
This in fact, gives us a great insight into the development of techniques used within prior wars and the advancement that has been made with technology of those discussed in previous sections. We can also see from this that the application of ultrasound has in fact been popular by the military and one could assume that there may be more progressed development within this field. Moreover, (Goodman, 2009) cites “There is, however, evidence to suggest that ultrasound has been considered by military and law enforcement authorities as a likely technology for so-called ‘non-lethal weapons’ for use in crowd control and ‘coercive interrogation’.” which is evident to this day. We can also see the application of hypersonic ultrasound as a means of public crowd control with the likes of The Mosquito Anti-Social Device (M.A.D), which emits high frequency sound, around 20,000hz and above, with a range of around 15 to 20 meters (Goodman, 2009). On the Compound Security System’s website, who are the company behind the M.A.D, they specify that the sine wave frequency played by the device, at 20kHz, can only be heard by those under 25 years of age (Compound Security, 2015). Thus, this system is targeted as a youth deterrent. The company goes on to state that field trials suggest that teenagers where acutely aware for the ultrasonic tone and would usually wish to move away after around ten minutes (Compound Security, 2015). This suggest that perhaps the device’s intended use is to create auditory discomfort for the target audience, in order for them to move away from a specific area. Moreover, devices similar to this have also been developed previously; though military and law enforcement have denied the use of ultrasonic devices it apparent that such exist. Instructions and a Patent for a ‘Phasor Pain Field Generator’ can be found, which emits ultrasonic frequencies at 20,000Hz to 25,000Hz as a schematic for a handheld self-defence device, specifying that it’s “intended for Law Enforcement, Personal Or For Qualified Acoustical Research” (Free Information Society, no date) & (De Laro Research, 2014). Within the description of this device, it also states “if at any time head or neck feels swollen or you feel light headed or sick to your stomach, it is an indication that you are being affected. Sometimes you may experience a continuous ringing in the ears even after the device is turned off” (Free Information Society, no date). One can draw a conclusion from the description of both the M.A.D and the ‘Phasor Pain Field Generator’ that the intended outcome if the the target to feel discomfort. It is not unreasonable to state that as technology has progressed within ultrasonic research and as more psychological effects of inaudible sounds are discovered, the perceptual military operations of sonic warfare have widened. These techniques of applying 20,000Hz as a means of deterrent of said ‘self-defence’ devices allow for more primary research within this field to be explored. As a result, this study will collect primary research within this area to allow for a greater insight into the application of these techniques.