Sonic Weapons and Crowd Control

The crowd is a particular social formation. If you are part of the crowd, stop thinking like an individual and independent control over your decision-making takes collective thinking crowd. If people in the crowd begin to shout - shout as well, if they start to disagree with something - you do not agree as well, if people begin to loot - loot as well. Handle a crowd dominated by primitive instincts is not just a problem of police officers, but recently also simple soldiers. A prime example is zfanatizované crowds in Afghanistan and Iraq, where everything is compounded by ignorance and excessive emotivity locals.

 Sound LRAD cannon on board the American war vessel 

Crowd control in combat zones

At the beginning of the invasion of Iraq or Afghanistan, Allied soldiers had no means to regulate or rozhánět angry residents - in addition to their weapons. Command armies soon realized that shooting into the air is not exactly a spectacular way to control the crowd - quite the contrary. The result may be greater escalation of the situation, not to mention the negative headlines in the newspapers.

Army engineers began to think about design so lethal (lethal) weapons capable paralyze, paralyze, scare or otherwise warn persons in the power of the crowd. One of the most effective was the "invention" of modern sonic weapons, able to support high-volume audio alert or paralyze the affected person.

The crowd - a group larger than about 40 people 
in the crowd there is the mob psychosis - the man in the crowd suppressing their own individuality, promoting the primitive instincts, sense of responsibility disappears. The crowd gives a sense of anonymity and security. One can behave as he would have never behaved. Wikipedia

Although there are many types of sonic weapons (eg, flash-bang), in our case, we will talk about the sonic (sound) cannons. It is actually a very powerful directional speakers, able only in a certain direction to broadcast the sound of very high energy.

LRAD sonic cannon

Kind of benchmark is the sound of American artillery equipment LRAD (Long Range Acoustic Device) able to induce unbearable pain affected persons or broadcast emphatic voice commands.

 LRAD sonic cannon 

LRAD broadcast bounded sound beam in a cone angle of 30 ° at a frequency of 2.5 kHz and the volume up to 150 dB. Although it goes against common sense, in this case, the sound spread celokruhově, but precisely and only in that narrow cone. If you stand just a few meters from the affected area, you will see just confused people writhing on the ground, lying just a few meters from you.

Sound is mechanical waves in matter, which is able to induce auditory perception. The frequency of this oscillation which one is able to perceive, are highly individual and is located approximately in the range 16 Hz to 20,000 Hz. Mechanical waves outside the frequency range of auditory perception does not, but sometimes also referred to as sound.
frequency below 16 Hz, infrasound, such as elephants can hear it. Frequency higher than 20 kHz ultrasound is, which can be perceived as dogs, dolphins and bats. Phenomena that are associated with the emergence and spread of the sound of his perception, is called acoustics. Wikipedia

Recall that the sound is not electromagnetic waves like light or radio waves, but the mechanical waves. Is produced by a sound source - the quivering body - atoms vibrated environment, usually air. Oscillations are then spread in the environment, so that the atoms of their neighboring atom vibrations transmitted up to the receiver - most often the human ear. In the case of guns must therefore LRAD sound source vibrates at 2500 vibrations per second.

Photo: Scheme of work LRAD sonic cannons / LRAD Corporation

Effective range LRAD sonic weapon is about 300 meters, in which the affected person feels severe headache and mental discomfort. However, if a person closer to a distance of 100 meters from the LRAD emitter, the pain becomes unbearable. Critical distance is then about 15 meters, which leads to permanent hearing damage.  

LRAD may not only serve to paralyze the crowd, but it can also transmit spoken commands - in this case up to a distance of nearly 9 km. Moreover, its electronic voice can modulate the way that sounded strong and autorativně. Surely you see yourself, there is a difference when you speak to a person with a weak high-pitched voice or a voice firm and strong.  

Sonic weapon could kill

An interesting feature is the ability of sonic works vibrate at a certain distance, type of material - if people need a variety of soft tissue. The engineer Vic Tandy for example, experimented with different frequencies that can vibrate the human eye.

The result of such attempts have been distorted vision of affected persons. Conclusions attempts even sounded eerily as test subjects reported that the eyes have seen the disturbing and intense flashes of gray "ghost". But this is not just some way to appease a mob.  

LRAD in action. Know the power of sound, but I suppose it's not full power 

But this is not everything, at frequencies of several hundreds of kHz to MHz (millions of cycles per second), an area of ​​ultrasound - inaudible to human ears, it can "vibrate" the human nervous system and internal organs - all with fatal consequences. In experiments on mice were in the high frequency performance and recorded such extensive damage to the lungs and heart ...

 

Let us mention that the deployment of LRAD sonic weapons count as the organizers of the Olympic Games in London. The weapon is not designed primarily against demonstrators, but against suspect ships sailing on the River Thames.