Vladimir Gavreau's Jericho Trumpet

Gavreau and his invention

During the 1950's, a French scientist named Vladimir Gavreau was doing robotics research.  He discovered a ventilation shaft in the building where he was working was making the people who worked there sick by way of very low frequency vibrations of a fan in the shaft.  The shaft was the perfect dimensions to amplify the vibrations of the fan.  When he figured this out, Gavreau turned his research instead to sonic weapons.  He developed what I can only call a "Jericho trumpet": a giant subsonic whistle that could knock down buildings.

They tested this whistle, which was blown by an air pump, on a special concrete housing they built for it at Versailles.  It almost knocked down part of Versailles and it destroyed its own concrete housing.  Another whistle almost killed the researchers; one of them ignored the pain enough to be able to shut off the device, and they were all sick for days after.


It does not take very much energy (aka volume) for infrasound to do great damage.  Such a device could be put into a remote controlled tank, or a flying drone, and inflict great harm on the battlefield. You can't direct or detect the direction infrasound goes in - it goes in all directions and permeates everything, so it would have to be remote controlled. 

At certain frequencies infrasound doesn't knock things down or damage internal organs, but instead it makes people feel uneasy or depressed.  The mistral wind, which is a seasonal coastal wind in the Mediterranean, does this naturally by way of infrasound.  Other natural infrasound phenomena include the Aurora Borealis, winds in the desert, earthquakes, tides, and air pressure changes from solar flares.  That uneasy feeling people get before a hurricane is from infrasound.

Sonic weapons exist today.  There is the crowd-controlling sound cannon, there is also a thing that looks like a wand that you can make it shriek at whoever you point at.  It uses a row of piezoelectric speakers.  They were thinking of carrying the wand things on airplanes as a way of attacking hijackers.  Do they have infrasonic weapons?  Who knows?  I wouldn't rule it out though. 

Even a rock band has experimented with sound weapons:  the band Throbbing Gristle used piezoelectric speakers tuned very close in pitch to drive away their annoying next door neighbors.  The difference between the two very high pitches was low level infrasound.  The band The Flaming Lips has used very low frequency in their recording "Zaireeka", although you would need a speaker system with a subwoofer for the full effect. 

Here is the most detailed article I have found on Dr. Gavreau's work and on the phenomenon of infrasound in general: http://www.hbci.com/~wenonah/history/gavreau.htm

Here is a pretty comprehensive article on the biological effects of sound
http://sites.google.com/site/appliedbiophysicsresearch/sound/infrasound/acoustic-trauma-bioeffects-of-sound