Sonic and ultrasonic weapons (USW) are weapons of various types that use sound to injure or incapacitate an opponent. Some sonic weapons make a focused beam of sound or of ultrasound; others produce an area field of sound. As of 2023 [update] military and police forces make some limited use of sonic weapons.
Extremely high-power sound waves can disrupt or destroy the eardrums of a target and cause severe pain or disorientation. This is usually sufficient to incapacitate a person. Less powerful sound waves can cause humans to experience nausea or discomfort.
The possibility of a device that produces frequency that causes vibration of the eyeballs—and therefore distortion of vision—was suggested by paranormal researcher Vic Tandy [1] [2] in the 1990s while attempting to demystify a "haunting" in his laboratory in Coventry. This "spook" was characterised by a feeling of unease and vague glimpses of a grey apparition. Some detective work implicated a newly-installed extractor fan, found by Tandy, that was generating infrasound of 18.9 Hz, 0.3 Hz, and 9 Hz.
A long-range acoustic device (LRAD) produces a 30 degree cone of audible sound in frequencies within the human hearing spectrum (20 - 20000 Hz). An LRAD was used by the crew of the cruise ship Seabourn Spirit in 2005 to deter pirates who chased and attacked the ship. [3] More commonly this device and others of similar design have been used to disperse protesters and rioters in crowd control efforts. A similar system is called a "magnetic acoustic device". [4] The Mosquito sonic devices have been used in the United Kingdom to deter teenagers from lingering around shops in target areas. The device works by emitting an ultra-high frequency blast (around 19–20 kHz) that teenagers or people under approximately 20 are susceptible to and find uncomfortable. Age-related hearing loss apparently prevents the ultra-high pitch sound from causing a nuisance to those in their late twenties and above, though this is wholly dependent on a young person's past exposure to high sound pressure levels.[ citation needed ] In 2020 and 2021, Greek authorities used long-range sound cannons to deter migrants on the Turkish border. [5]
High-amplitude sound of a specific pattern at a frequency close to the sensitivity peak of human hearing (2–3 kHz) is used as a burglar deterrent. [6]
Some police forces have used sound cannons against protesters, for example during the 2009 G20 Pittsburgh summit, [7] the 2014 Ferguson unrest, [8] and the 2016 Dakota Access Pipeline protest in North Dakota, [9] among others.
It has been reported that "sonic attacks" may have taken place in the American embassy in Cuba in 2016 and 2017 ("Havana syndrome"), leading to health problems, including hearing loss, in US and Canadian government employees at the US and Canadian embassies in Havana. [10] However, more recent reports hypothesize microwave energy as the cause [11] [12] [13] or their bodies tricking themselves via a mass psychogenic condition caused by extended periods of stress, such as working in an embassy of a nation considered hostile to your own. [14]
Studies have found that exposure to high intensity ultrasound at frequencies from 700 kHz to 3.6 MHz can cause lung and intestinal damage in mice. Heart rate patterns following vibroacoustic stimulation has resulted in serious negative consequences such as atrial flutter and bradycardia. [15] [16]
See: Microwave auditory effect
The extra-aural (unrelated to hearing) bioeffects on various internal organs and the central nervous system included auditory shifts, vibrotactile sensitivity change, muscle contraction, cardiovascular function change, central nervous system effects, vestibular (inner ear) effects, and chest wall/lung tissue effects. Researchers found that low-frequency sonar exposure could result in significant cavitations, hypothermia, and tissue shearing. No follow up experiments were recommended. Tests performed on mice show the threshold for both lung and liver damage occurs at about 184 dB. Damage increases rapidly as intensity is increased.[ citation needed ] The American Institute of Ultrasound in Medicine (AIUM) has stated that there have been no proven biological effects associated with an unfocused sound beam with intensities below 100 mW/cm² SPTA or focused sound beams below an intensity level of 1 mW/cm² SPTA. [17]
Noise-induced neurologic disturbances in scuba divers exposed to continuous low-frequency tones for durations longer than 15 minutes has involved in some cases the development of immediate and long-term problems affecting brain tissue. The symptoms resembled those of individuals who had suffered minor head injuries. One theory for a causal mechanism is that the prolonged sound exposure resulted in enough mechanical strain to brain tissue to induce an encephalopathy. Divers and aquatic mammals may also suffer lung and sinus injuries from high intensity, low-frequency sound. This is due to the ease with which low-frequency sound passes from water into a body, but not into any pockets of gas in the body, which reflect the sound due to mismatched acoustic impedance. [18]
Ultrasound is sound with frequencies greater than 20 kilohertz. This frequency is the approximate upper audible limit of human hearing in healthy young adults. The physical principles of acoustic waves apply to any frequency range, including ultrasound. Ultrasonic devices operate with frequencies from 20 kHz up to several gigahertz.
In physics, attenuation is the gradual loss of flux intensity through a medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and sound at variable attenuation rates.
The microwave auditory effect, also known as the microwave hearing effect or the Frey effect, consists of the human perception of sounds induced by pulsed or modulated radio frequencies. The perceived sounds are generated directly inside the human head without the need of any receiving electronic device. The effect was first reported by persons working in the vicinity of radar transponders during World War II. In 1961, the American neuroscientist Allan H. Frey studied this phenomenon and was the first to publish information on the nature of the microwave auditory effect. The cause is thought to be thermoelastic expansion of portions of the auditory apparatus, although competing theories explain the results of holographic interferometry tests differently.
Non-lethal weapons, also called nonlethal weapons, less-lethal weapons, less-than-lethal weapons, non-deadly weapons, compliance weapons, or pain-inducing weapons are weapons intended to be less likely to kill a living target than conventional weapons such as knives and firearms with live ammunition. It is often understood that unintended or incidental casualties are risked wherever force is applied, however non-lethal weapons minimise the risk of casualties as much as possible. Non-lethal weapons are used in policing and combat situations to limit the escalation of conflict where employment of lethal force is prohibited or undesirable, where rules of engagement require minimum casualties, or where policy restricts the use of conventional force. However, these weapons occasionally cause serious injuries or death due to allergic reactions, improper use and/or other factors; for this reason the term "less-lethal" has been preferred by some organizations as it describes the risks of death more accurately than the term "non-lethal", which some have argued is a misnomer.
Infrasound, sometimes referred to as low frequency sound, describes sound waves with a frequency below the lower limit of human audibility. Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high. Although the ear is the primary organ for sensing low sound, at higher intensities it is possible to feel infrasound vibrations in various parts of the body.
A directed-energy weapon (DEW) is a ranged weapon that damages its target with highly focused energy without a solid projectile, including lasers, microwaves, particle beams, and sound beams. Potential applications of this technology include weapons that target personnel, missiles, vehicles, and optical devices.
A long-range acoustic device (LRAD), acoustic hailing device (AHD) or sound cannon is a specialized loudspeaker that produces sound at high power for communicating at a distance. It has been used as a method of crowd control, which has caused permanent hearing damage, having an extremely high decibel capacity. Other uses have included for negotiations in siege situations; to deal with piracy at sea; for mass notification during natural disasters or other emergencies; and by defense forces, including several navies.
The Active Denial System (ADS) is a non-lethal directed-energy weapon developed by the U.S. military, designed for area denial, perimeter security and crowd control. Informally, the weapon is also called the heat ray since it works by heating the surface of targets, such as the skin of targeted human beings. Raytheon had marketed a reduced-range version of this technology. The ADS was deployed in 2010 with the United States military in the Afghanistan War, but was withdrawn without seeing combat. On August 20, 2010, the Los Angeles Sheriff's Department announced its intent to use this technology to control incarcerated people in the Pitchess Detention Center in Los Angeles, stating its intent to use it in "operational evaluation" in situations such as breaking up prisoner fights. As of 2014, the ADS was only a vehicle-mounted weapon, though U.S. Marines and police were both working on portable versions. ADS was developed under the sponsorship of the Department of Defense Non-Lethal Weapons Program with the Air Force Research Laboratory as the lead agency. There are reports that Russia and China are developing their own versions of the Active Denial System.
The brown note, also sometimes called the brown frequency or brown noise, is a hypothetical infrasonic frequency capable of causing fecal incontinence by creating acoustic resonance in the human bowel. Considered an urban myth, the name is a metonym for the common color of human faeces. Attempts to demonstrate the existence of a "brown note" using sound waves transmitted through the air have failed.
Nerve induction is a theoretical method of creating a sensation by stimulation of the sensory nerves rather than by actual stimulus.
Sound from ultrasound is the name given here to the generation of audible sound from modulated ultrasound without using an active receiver. This happens when the modulated ultrasound passes through a nonlinear medium which acts, intentionally or unintentionally, as a demodulator.
Flicker vertigo, sometimes called the Bucha effect, is "an imbalance in brain-cell activity caused by exposure to low-frequency flickering of a relatively bright light." It is a disorientation-, vertigo-, and nausea-inducing effect of a strobe light flashing at 1 Hz to 20 Hz, approximately the frequency of human brainwaves. The effects are similar to seizures caused by epilepsy, but are not restricted to people with histories of epilepsy.
Electronic pest control is the name given to any of several types of electrically powered devices designed to repel or eliminate pests, usually rodents or insects. Since these devices are not regulated under the Federal Insecticide, Fungicide, and Rodenticide Act in the United States, the EPA does not require the same kind of efficacy testing that it does for chemical pesticides.
In physics, sound is a vibration that propagates as an acoustic wave through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the reception of such waves and their perception by the brain. Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of 17 meters (56 ft) to 1.7 centimeters (0.67 in). Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges.
Acoustic harassment and acoustic deterrents are technologies used to keep animals and in some cases humans away from an area. Applications of the technology are used to keep marine mammals away from aquaculture facilities and to keep birds away from certain areas. The devices have also been employed to keep marine mammals away from fishing nets. The devices are known as acoustic harassment devices (AHDs) and acoustic deterrent devices, which are smaller AHDs or intended as an awareness tool to warn species to the presence of danger rather than as a tool of harassment at a much louder level.
An ultrasonic toothbrush is an electric toothbrush designed for daily home use that operates by generating ultrasound in order to aid in removing plaque and rendering plaque bacteria harmless. It typically operates on a frequency of 1.6 MHz, which translates to 96,000,000 pulses or 192,000,000 movements per minute. Ultrasound is defined as a series of acoustic pressure waves generated at a frequency beyond human hearing.
The Embassy of the United States of America in Havana is the United States of America's diplomatic mission in Cuba. On January 3, 1961, U.S. President Dwight D. Eisenhower severed relations following the Cuban Revolution of the 1950s. In 1977, U.S. President Jimmy Carter and Cuban leader Fidel Castro signed an Interests Sections Agreement that permitted each government to operate from its former embassy in Havana and Washington D.C., which were called Interests Sections; they were prohibited from flying their respective flags. Cuban President Raúl Castro and U.S. President Barack Obama restored full diplomatic connections on July 20, 2015.
SonicEnergy is a US company that claims to be developing a wireless charging system that works via ultrasound.
Havana syndrome is a disputed medical condition reported primarily by U.S. diplomatic, intelligence, and military officials stationed in overseas locations. Most of the affected individuals reported an acute onset of symptoms associated with a perceived localised loud sound, followed by chronic symptoms that lasted for months, such as balance and cognitive problems, insomnia, and headaches. The first cases were reported by U.S. and Canadian embassy staff in Havana, Cuba, though earlier incidents may have occurred in Frankfurt, Germany. Starting in 2016 through to 2021, several hundred U.S. intelligence and military officials and their families reported having symptoms in overseas locations including China, India, Europe, Hanoi, as well as in Washington, D.C., USA.
The Moscow Signal was a reported microwave transmission varying between 2.5 and 4 gigahertz, directed at the U.S. Embassy in Moscow from 1953 to 1976, resulting in an international incident. There were no significant health effects on embassy staff, although this conclusion has been disputed.
