IN 1964, THE Geneva Convention outlawed the use of seven-cycle sound as a weapon because it could not isolate military targets from civilian. In other words, it met the working definition of a weapon of mass destruction.

     The US Army had successfully developed a device that, when mounted on the back of a jeep, could direct a beam of seven-cycle sound that would kill every living thing in its path for a distance of five miles -- birds, trees, grass, insects, humans …

     This sound -- below the threshold of hearing -- could penetrate more than 150 feet of reinforced concrete and more than 16 feet of solid lead.

     Seven cycles is the cycle of life. Every living cell vibrates at this frequency. Seven-cycle sound sets up sympathetic vibrations that agitate each living cell to vibrate more aggressively -- much like when a dog trots across a bridge at just the right frequency, it can cause the bridge to vibrate so violently that it literally collapses.

     When cells vibrate in this way, the friction between them increases, causing them to overheat. At 106 degrees, the human brain becomes delirious, effectively paralyzing both thought and motor functions. At 115 degrees, death is almost instantaneous. It takes only seconds for seven-cycle sound to overheat the brain.

     It would take a whistle the size of a football field to generate seven-cycle sound. An organ pipe would need to be more than sixty feet tall and wide enough to fit eight men into it side by side. Both designs would require sustained winds in the range of a level-five hurricane.

     The army did it with an array of sixty wooden reeds, powered by the equivalent of a leaf blower, but not before three researchers died trying to make it directional.

     Seven-cycle sound kills. Eight-cycle sound paralyzes.

     The one responsible for perfecting seven- and eight-cycle directional sound didn't stop until he developed a defense which, as it turns out, consists of a matrix of paper straws, which converts both frequencies into harmless currents of air.