Heading the Electro-Acoustical Laboratory in Marseilles,Professor Vladimiar Gavreau began his investigations of Infrasound after discovering that a nearby factory's giant ventilator system was causing headaches and nausea among his staff.
His research revealed that low vibrations below the hearing level can create a sort of pendulum action, a reverberation in solid objects that quickly builds up to intolerable levels of intensity.
To study these effects, and to control the propagation of infrasound, the team designed and constructed a 5' long whistle connected to a compressed air supply as the power or amplitude at these low levels has to be extremely high in order to be of a dang erous nature, in excess of 160 db, 180 db or above would result in death.
Both Infrasound and Ultrasound would kill at these db levels.
At reduced levels, Infrasound pulsing at 3.5hz, all other sounds, including the human voice, seem to undulate rhythmi cally, prolonged exposure can create permanent injury.
A collegue of Gavreau's (R. Levasseur), had modified an ordinary police whistle by adding a resonant cavity at one end which lowered its pitch and producing a wavelength in excess of 31 metres; magnifying it's volume hundreds of times.
When blown, the effect on Levasseur was so distructive and so intensely shocking that he became a chronic invalid.
German experiments have also proven that inaudible low frequencies can produce nausea, fright and panic; and in America, powerful rockets which also produce low frequences have caused blurred vision, dizziness, lassitude, and disturbing vibration of the chest and stomach.
Professor Gavreau says "It not only affects the ears, but is also works directly on the internal organs, there is a rubbing between the various organs because of a sort of resonance. It provokes an irritation so intense that for hours afterwards any low pitched sound seems to echo through ones body"
. Gavreau's work was partially aimed at military applications.
Was the weapon to hand always an ice-pick?The pointed shape and the ease with which it could have been used as a weapon - it could have killed a few in the prohibition territory wars though...
For the military, rather that music boosted morale and gave those awaiting possible death something else to think about...
Here is an account from occupied territory...