Non-Lethal Acoustic Weapons

We have already talked about non-lethal weapons in general. Here, we will focus on the acoustic non-lethal weapons and analyze some of the types of non-lethal weapons that use sound as a deterrent. We will learn how they work, their purpose, and some of their history.

A non-lethal acoustic weapon is a tool or a device that uses sound to immobilize, deafen, threaten, discourage a target or to disperse crowds of people such as rioters. In some cases, they are handy for addressing crowds and for public safety and for transmitting sound over long distances. In many cases, these devices use technologies like ultrasound and infrasound, where the frequencies emitted by devices are higher or lower than what a normal human being can hear. Some of these weapons also use technologies like the directional sound waves, which makes the sound audible only to those that find themselves in that beam.

Cue the mysterious attack on the US embassy in Havana, Cuba, where an attacker used an unknown sound weapon on the employees within the embassy. The attack was inaudible to the people inside the embassy, but the noise caused a lot of damage. Non-lethal acoustic weapons can be a powerful way to control rioters and generally disturb the receiving party.

What is a Non-Lethal Acoustic Weapon?

Non-lethal acoustic weapons are devices that can be used primarily by police officers to control, disable, or immobilize a target without killing them. They have been in use and development ever since the 1970s. But some technologies are pretty much still in progress. These weapons work in different ways: some use ultrasound, which uses high-frequency beams of sound that are inaudible or almost inaudible to a person but can cause severe damage, depending on the strength of the signal. Infrasound technology causes similar effects, but the difference is that these devices emit lower-frequency sounds and are also inaudible in many cases. Then we have the directional, non-lethal weapons that emit sound waves of various frequencies in a specific direction.

Non-lethal acoustic weapons can cause a variety of different effects, which can be physical or psychological. Among the physical effects, we have a feeling of nausea, immobilization, inability to move, or to operate correctly, a general sense of sickness. In severe cases, these weapons can even cause serious damage like internal organ damage, and even death if someone is under its effect for longer. Also, a severe impact of some of these weapons might be to cause hearing issues and even deafness. Some people might have to use hearing aid after being affected by these weapons.

Among the most commonly used non-lethal acoustic weapons are LRADs, which have been in development since the late 20th century, but have rarely been used by the police until the 2010s, when they proved themselves to be useful for riot control and public addressing. By then, they were used for military purposes mainly, and to send messages over long distances.

Among infrasound, ultrasound, and directional speakers, some other fascinating technologies are used for creating non-lethal acoustic weapons. Under the infrasound category, we also find resonance weapons, which use vibrations to generate a feeling of nausea and to make someone uncomfortable. Let’s go over some of them and see how they work. 

Infrasound Acoustic Weapons

Infrasound or a low-frequency sound is a series of sound waves with low frequency. The frequencies are generally below the threshold of human audibility, which is at around 20Hz. While these sounds are inaudible, they can cause some very significant physical effects on the human body. Some people described the feeling of receiving infrasounds like a feeling of seasickness. Physical impacts of an infrasound source include nausea, vomiting, disorientation, immobilization, internal organ damage, and discomfort. It is hard to withstand these waves of infrasounds for longer, which is why we associate them with crowd control and even for military use.

During the 20th century, infrasound technology was developed by war scientists to reduce the death toll during wars. The military has rarely used these devices for warfare. There is even a law that prevents this type of conquest. 

While infrasound is not used very often as a non-lethal weapon, there are many sources of infrasound that can happen as a natural occurrence itself, and in some devices that were created by humans. Animals such as elephants and whales use infrasounds to communicate with each other, which is why it is almost impossible to hear whales. In many cases, natural events and phenomena can cause infrasounds. In this category, we find severe weather effects, earthquakes, waterfalls, avalanches, and even lighting.

As for the human-produced source of infrasound, there are some sources that many people would not associate with infrasound. Here, we find devices like loudspeakers, various engines (especially diesel engines), wind turbines, woofers and subwoofers, and multiple events caused by a human such as explosions and sonic boom. Nikola Tesla experimented with devices that produced low-frequency sound waves. He claimed that his device would be able to shake a building so much that it would be reduced to rubble. These wild assertions have never been proved and people remain fascinated with some of Nikola Tesla’s crazy inventions.

As a non-lethal weapon, infrasound is being introduced by Chinese authorities especially, to control crowds of rioters and people. Within such devices, we know various infrasound speakers, sonic guns that emit directed waves of low-frequency sounds, low-frequency acoustic bullets, and even amplifiers. In China, tools or weapons like sonic guns are being used by authorities to control crowds of rioters. While such a threat is still in development, it will have the ability to immobilize and disable a target altogether.

Ultrasound Acoustic Non-Lethal Weapons

On the other side, we have the ultrasound non-lethal acoustic weapons. These weapons use sound waves with high frequencies and are usually emitted by the device in a beam of directed energy. Ultrasounds are generally not heard by a normal human ear, which can detect sounds of up to 20kHz in frequency. Ultrasound is also used for medicinal purposes and is a noise made by various animals and natural effects.

A healthy ear does not hear ultrasounds, but a human being feels them. One of the primary reasons why ultrasounds can be so powerful as weapons are their high frequency, and their sheer power. Sometimes, they can even be too powerful to be regarded as non-lethal, as they can cause death. In light to moderate cases, ultrasounds can cause general unease and uncomfortable feelings, and some more severe issues like organ damage.

They use smaller wavelengths and higher sound frequencies, which makes them inaudible to people that don’t find themselves in this direct beam of sound. That feature made directional speakers and LRADs possible, as they both use ultrasonic sound. There are also some other non-lethal weapons, most notably, the “Mosquito.” It is a device that uses ultrasounds that are usually only audible to young persons, and their purpose is to prevent more youthful people from loitering in certain areas where such behavior is unwanted.

The morality of the Mosquito is controversial for many people but is commonly used to prevent vandalism and drug use among young people. It is often seen mainly within the UK, but also in some other European countries such as France, Denmark, Italy, Spain, Germany, Switzerland, and also in the US and Australia. The way the device works is that it emits sounds on the higher end of the hearing spectrum, usually around 18kHz, which is, most of the time, only audible to younger persons. It bears the name “the Mosquito” because it makes similar, annoying sounds that a mosquito does.

Directed Ultrasound Devices

When it comes to ultrasonic non-lethal weapons, the technology that is necessary for making such weapons has been in development and is still in progress today. Only now, we are starting to realize the potential of these weapons, as they can be crucial for a massive variety of things.

  • Crowd Control
  • Long-distance communication
  • Public safety in airports, significant buildings where there are many people
  • Museums, exhibits (small directional speakers like Soundlazer)
  • Commercial advertising
  • Security alarms
  • and much more.

The effects of non-lethal directed ultrasound devices can vary significantly. For more significant devices like LRADs, the consequences can be much more severe than in smaller devices like directional speakers. The general effects, if used moderately, can be used for addressing crowds of people and for potentially dispersing groups of people. Standing in front of an LRAD that is working can be quite intimidating, and it can have physical effects on a person. Mainly, it can cause distress, even nausea, disorientation, confusion, and it can be useful for dispersing the crowds.

LRADs are also very important for military uses. Not only is it practical for long-distance communication, but it can be vital for defense. In some cases, mainly from Africa, LRADs were crucial for repelling pirate attacks in countries like Somalia and Liberia. Interestingly, these uses of LRADs were quite successful, as they managed to deter the pirates away from the ships under attack. That was the case in 2005 in Somalia in 2008 in Liberia, and there were some subsequent uses as well.

LRAD (Long Range Acoustic Device) is a non-lethal directed ultrasonic weapon that uses ultrasonic waves of sound to make a directed beam of energy. These beams work in such a way that these high-frequency waves of sound move quickly at a frequency of 2kHz. The noise is entirely audible for people that are within that beam, and it can even be harmful if the person stands close to the device. LRADs often take the shape of a dish. It then lays on top of a vehicle, where another person operates it. This beam of directed energy can cause harm to people that stand close to the device; it can immobilize and stress a person, and it can impair their hearing if the tool is powerful enough.

As for its use, it can be handy for many things. Most notably, LRADs play an essential role in long-distance communication that is especially applicable at sea. They can also be beneficial for crowd control, for addressing crowds of people, and for advertising purposes. We have always been fascinated with the technology used in LRAD. Here is an interesting article about how an LRAD works.

Directional Speakers might not be a weapon in its essence, but it can be used for similar purposes than an LRAD, but on a much smaller scale. These, too, use ultrasonic waves to project sound in a directed beam, where only the person or the persons standing within that beam can hear the noise. Directional speakers have many essential uses. Most notably, they can be used for public safety in airports or subways for playing safety messages, and in museums and exhibits. As a non-lethal weapon, it can be used for personal defense, and for deterring robbers from one’s house by being incorporated into the alarm system.

Soundlazer works in such a way that the high-frequency waves of sound move back and forth quickly, which makes the noise audible only to those standing in the beam’s direction. Other people around the device will not hear a thing, which can be an advantageous way to use it as a non-lethal weapon on a specific target.

Sonic Explosives

Another way of using ultrasound for non-lethal purposes is by incorporating it into explosives. These can come in the shape of sonic grenades, bombs, mines, and sonic cannons. These can be extremely helpful for controlling crowds of people such as protesters, but also for personal defense, and even in warfare. Such explosives aim to impede the hearing ability of a person for a short amount of time. Some can also impair the hearing ability for more extended periods.

A sonic grenade works in such a way that it incorporates roughly the same design as a standard grenade, as it has a pin that needs to be pulled out by the user, and then the countdown begins. After this countdown, the missile will make a sonic explosion, which can be pretty unbearable, especially if the projectile is potent. The strength of these grenades can vary; in some cases, they are not very powerful, and in others, they can cause quite a lot of discomfort.

Sonic mines and cannons work in similar ways, but they feature different designs. The goal remains to disorientate the recipient of the explosion slightly and to operate non-lethally. Many of these weapons are still very much in their research and experimenting stages and development. They could be a form of non-lethal acoustic weapons for the future, though.