From Issue 5 Evil Winter 2001/02 - The Acoustics of War - Daria Vaisman [Daria Vaisman is research editor at the New York Press]

By the early 1990s, the United States was reassessing its self-image. The major conflicts of the last century—the two World Wars and Vietnam—had, for the most part, already been consigned to history (for a younger generation, they were only more media kitsch). But a protracted Cold War had kept the United States in a defensive posture for decades; now that the USSR had dissolved, the US no longer worried about the threat of a nucle­ar attack. The military wanted weapons that reflected the US’s new international role. What to do? In 1991, the Pentagon issued a directive to test an emerging class of arms: Called "non-lethals," these weapons were meant to disable their targets "in such a way that death or severe permanent disability was unlikely." ….. By 1996, the US had invested nearly $37 million in research for non-lethal weapons.

 The 1907 Hague Convention clearly prohibits the use of "arms, projectiles, or materials calculated to cause unnecessary suffering.".  But it presented an interesting question: Was it possible to project sound at a precise decibel level that caused pain without permanent damage? Furthermore, there was anecdotal evidence suggesting that at the right frequency, infrasound would "liquefy [people's] bowels and reduce them to quivering diarrheic masses."
……………By 1999, Human Rights Watch issued a memorandum suggesting that a new protocol dealing with acoustic weapons be added to the Convention on Conventional Weapons.

……….Of the acoustic prototypes that actually exist, several have actually proved viable. In his 1981 book Riot Control, Colonel Rex Applegate showcased a blueprint for a curdler (which he aptly nicknames "the people repeller"), which looks like a British police club and emits a shrieking, pulsating sound equal to 120 decibels at 30 feet. [Of the other actual devices] the Compression Air Device [CAD] generates energy at a specific low frequency from a combustion engine at its base, and directs the sound out of a long tube. The Ring Vortex Cannon, which ….is the most viable of the acoustic weapons, is actually an acoustic and kinetic cannon that sends out an infrasound donut-shaped shock wave combined with a toxic chemical spray. The vortex ring travels at hundreds of miles per hour, and hits its target with the force of a rubber blanket.­

………. Non-lethal technology can turn "worse-than-lethal," in the words of Harvey Sapolsky, head of Security Studies at MIT and one the first people to look at non-lethals in the US. When I spoke to Sapolsky over the phone, he told me stories he heard of Israelis stripping rubber off bullets and Americans using lasers to illuminate Somali targets in order to shoot them.

 For Sapolsky, using acoustics raises the issue of intervention in the first place. "You should be asking whether the situation is worth doing at all. My idea? You're going to think I'm crazy. Leave them presents, for example: On the border of North and South Korea, leave all sorts of stuff from shopping malls, stuff they've never seen before. Wrap it up really well so it takes a long time to unwrap. Slow them down—that's the logic behind landmines."

Coates, J. (1972) Non-Lethal Police Weapons. Technology Review, June, pp. 49-56.

Weapons research, conducted on very slim budgets, has largely taken the form of
speculative endeavors by commercial organization[s] serving an uncertain market.
As a result, new materials are frequently introduced on a shockingly slim basis of
evidence as to their effectiveness, reliability or safety.

The sonic weapon of Vladimir Gavreau - Gerry Vassilatos

Dr. Gavreau and his research team now carefully investigated the effects of their "infrasonic organ" at various intensity levels and pitch. Changing the spring tension on shock mounts, which held the fan motor, it was possible to change the pitch. Various infrasonic resonances were established throughout the large research building. Shutting the windows blocked most of the symptoms. When the window was again opened, however weak as the source was made, the team felt the nauseating effects once again. In the business of mili­tary research, Dr. Gavreau believed he had discovered a new and previously "unknown weapon" in these infrasounds. Aware of the natural explosives by which infrasonics are generated, Dr. Gavreau began to speculate on the ap­plication of infrasonics as a defense initiative.

The haphazard explosive ef­fects of natural infrasound in thunderclaps were quite effective in demon­strating what an artificial "thunder-maker" could do. But, how could a thun­derclap be artificially generated in a compact system? These thoughts stimu­lated theoretical discussions on the possibility of producing coherent infrasound: an infrasonic "laser".

The first devices Dr. Gavreau implemented were designed to imitate the "accident" which first made his research group aware of infrasonics. They designed real organ pipes of exceedingly great width and length. The first of these was six feet in diameter and seventy-five feet long. These designs were tested outdoors, securely propped against protective sound-absorbent walls. The investigators stood at a great distance. Two forms of these infrasonic organ pipes were built. The first utilized a drive piston, which pulsed the pipe output. The second utilized compressed air in a more conventional manner.

The main resonant frequency of these pipes occurred in the "range of death", found to lie between three and seven cycles per second. These sounds could not be humanly heard, a distinct advantage for a defense system. The effects were felt however. The symptoms come on rapidly and unexpectedly, though the pipes were operating for a few seconds. Their pressure waves impacted against the entire body in a terrible and inescapable grip. The grip was a pressure which came in on one from all sides simultaneously, an enve­lope of death.

Next came the pain, dull infrasonic pressure against the eyes and ears. Then came a frightening manifestation on the material supports of the device itself. With sustained operation of the pipe, a sudden rumble rocked the area, nearly destroying the test building. Every pillar and joint of the massive struc­ture bolted and moved. One of the technicians managed to ignore the pain enough to shut down the power supply.

These experiments with infrasonics were as dangerous as those early investigations of nuclear energy. Dr. Gavreau and his associates were dangerously ill for nearly a day after these preliminary tests. These maladies were sustained for hours after the device was turned off. Infrasonic assaults on the body are the more lethal because they come with dreadful silence. The eye­sight of Dr. Gavreau and his fellow workers were affected for days. More dangerously were their internal organs affected: the heart, lungs, stomach, intestinal cavity were filled with continual painful spasms for an equal time period.

Musculature convulses, torques, and tears were the symptoms of infra­sonic exposure. All the resonant body cavities absorbed the self-destructive acoustic energy, and would have been torn apart had the power not been extinguished at that precise moment. The effectiveness of infrasound as a defense weapon of frightening power having been demonstrated "to satisfaction", more questions were asked. After this dreadful accident, approaching the equipment once again was almost a fearful exercise. How powerful could the output of an infrasonic device be raised before even the operating engi­neers were affected?

With greatest caution and respect for the power with which they worked, Dr. Gavreau began recalculating all of his design parameters. He had grossly misjudged the power released by the pipes. He had, in fact, greatly lowered those calculated outputs for diagnostic purposes. Never had he imagined that these figures were actually far too great in the world of infrasound!

Empirical data being the only way to determine how infrasonic energy correlated with both biological and material effect, the tests were again attempted with a miniature power supply. First, the dimensions of these devices had to be greatly reduced. Their extreme length was objectionable. In order to provide absolutely safe control of the deadly blasts, several emergency cutoff switches were provided. These responded to the radiated infrasonic pressure wave. The intensity could be absolutely limited by use of automated barometric switches.

In an attempt to achieve more compact and controllable infrasound generators, Dr. Gavreau designed and tested special horns and "whistles" of vari­ous volumes. These were each remarkably simple flat circular resonant cavi­ties, having a side output duct. They were simply the large analogues of fog­horns and police whistles. These flat forms were volumetrically reduced in successive design stages because it was found that their output was far too great. The infrasonic foghorns could produce a frightening two kilowatts of infrasonic energy, at a pitch of one hundred fifty cycles per second.

The flat "police whistles" were more easily designed to required specifications. Their overall characteristics were quite simple to determine, a math­ematical formula being devised for the purpose.

The whistle's resonant pitch was found by dividing its diameter into a numerical constant of 51. Increas­ing the depth of the whistle effectively increased its amplitude. A whistle 1.3 meters in diameter produced an infrasonic pitch of 37 cycles per second. This form violently shook the walls of the entire laboratory complex, though its intensity was less than 2 watts infrasonic power.

The sonic weapon of Vladimir Gavreau - Gerry Vassilatos

Infrasound produces varied physiological sensations which begin as vague “irritations”. At certain pitch, infrasound produces physical pressure. At specific low intensity, fear and disorientation. Nazi propaganda engineers methodically used infrasound to stir up the hostilities of crowds who were gathered to hear their madman. The results are historical nightmares.

At a very specific pitch, infrasound explodes matter. At others, infrasound incapacitates and kills. Organisms rupture in its blast. Sea creatures use this power to stun and kill prey………………..

Tesla used vibrating platforms as an aid to vitality. He delighted in "toning the body" with vibrational platforms of his own design. Mounted on heavy rubber pads, these platforms were vibrated by simple motorized "eccentric" wheels.
 
Their mild use, for a minute, could be pleasantly stimulating. The effects invigorating the whole body for hours thereafter. Excessive use would produce grave illness however, excessive aggravations of the heart being the most dangerous aspect of the stimulation. The entire body "rang" for hours with an elevated heart rate and greatly stimulated blood pressure. The effects could be deadly.

In one historic instance, Samuel Clemens, Tesla's close friend, refused to descend from the vibrating platform. Tesla was sorry he had allowed him to mount it. After repeated warnings, Tesla's concern was drowned out by both the vibrating machine and Clemens' jubilant exaltations and praises. Several more seconds and Clemens nearly soiled his white suit, the effects of infrasound being "duly recorded".

Tesla often went to great lengths in describing the effects of infrasound to newspaper reporters who, behind his back, scoffed at the notion that a "little sound" could effect such devastations. Yet, it was precisely with such a "little sound" that Tesla nearly brought down his laboratory on Houston Street. His compact infrasonic impulsers were terribly efficient. Tesla later designed and tested infrasonic impulse weapons capable of wrecking buildings and whole cities on command.