Security forces could employ the weapon to overcome resistance without resorting to force, their paramount aim. But experts warn that the effects of prolonged exposure are unknown.
The army employed the new device, which it dubbed "The Scream," at a recent violent demonstration by Palestinians and Jewish sympathizers against Israel's West Bank separation barrier.
Protesters covered their ears and grabbed their heads, overcome by dizziness and nausea, after the vehicle-mounted device began sending out bursts of audible, but not loud, sound at intervals of about 10 seconds. An Associated Press photographer at the scene said that even after he covered his ears, he continued to hear the sound ringing in his head.
A military official said the device emits a special frequency that targets the inner ear. Exposure for several minutes at close range could cause auditory damage, but the noise is too intolerable for people to remain in the area for that long, he said.
Another official, also speaking on condition of anonymity because of his sensitive position, said the device hasn't been tested on subjects for hours at a time, so he couldn't discuss effects from prolonged exposure.
He said there was no direct connection between the recent introduction of "The Scream" and the forcible removal of settlers who resist evacuation orders, which is to begin in mid-August. But he didn't rule out the possibility of using it to root out settlers if persuasion fails.
The other official said "The Scream" could be used if protesters march on Gaza settlements or take up military positions.
"The whole issue of non-lethal is viewed from a desire not to get into a situation where soldiers are in distress and the consequences would be harsher than expected," he explained.
He said the military is still evaluating the device's debut performance in the field.
John Pike, director of the GlobalSecurity.org think tank in Alexandria, Va., said he believed last Friday's demonstration was the first case of such technology making it out of the laboratory and into the field. He said the U.S. and possibly China and Russia are developing acoustic weapons.
"I'm not aware of any other agency that is actively using it at this point," Pike said.
The military offered few details on the device, but Pike said he assumed it worked on very low frequencies that set off resonance in the inner ear. He said he was unaware of potential damage besides possible hearing loss.