The equipment, called a Long Range Acoustic Device, or LRAD, is a so-called "non-lethal weapon" developed after the 2000 attack on the USS Cole off Yemen as a way to keep operators of small boats from approaching U.S. warships.

The devices have been used on some U.S. ships since last summer as part of a suite of protection measures.

Now, the Army and Marines have added this auditory barrage dispenser to their arms ensembles. Troops in Fallujah, a center of insurgency west of Baghdad, and other areas of central Iraq in particular often deal with crowds in which lethal foes intermingle with non-hostile civilians.

The developer of the LRAD, American Technology Corp. of San Diego, recently got a $1.1 million contract from the U.S. Marine Corps to buy the gadgets for units deployed to Iraq. The Army also sent LRADs to Iraq to test on vehicles.

Some of the Iraq-bound devices will be used by members of the 1st Marine Expeditionary Force and the 3rd Marine Aircraft Wing, both recently deployed to the western province of Al Anbar, a largely barren, predominantly Sunni Muslim area.

Though not officially part of the military's Joint Non-Lethal Weapons Directorate, the 45-pound, dish-shaped device belongs to a developing arsenal of technologies intended not to kill but to deter.

Another such weapon, expected to be tested in the field soon, is the Active Denial System. It seeks to repel enemies with a painful energy beam.

Carl Gruenler, vice president of military and government operations for American Technology Corp., said LRADs are "in the beginnings of being used in Baghdad," though he said he lacked "initial feedback" on how they are working.

Dubbed "The Sound of Force Protection" in a company brochure, the devices can broadcast sound files containing warning messages. Or they can be used with electronic translating devices for what amounts to "narrowcasting."

If crowds or potential foes don't respond to the verbal messages, the sonic weapon, which measures 33 inches in diameter, can direct a high-pitched, piercing tone with a tight beam. Neither the LRAD's operators or others in the immediate area are affected.

The devices "place distance between the Marine and their threat, giving him/her more time to sort out a measured and appropriate response," Lt. Col. Susan Noel, force protection officer for the 1st Marine Expeditionary Force, said in an ATC statement announcing the contract.

Gruenler compares the LRAD's shrill tone to that of smoke detectors, only much louder. It can be as loud as about 150 decibels; smoke detectors are in the 80 to 90 decibel range.

"Inside 100 yards, you definitely don't want to be there," said Gruenler, adding that the device is recommended for a range of 300 yards or less.

Hearing experts say sound that loud and of that high a frequency - about 2,100 to 3,100 hertz - could be dangerous if someone were exposed to it long enough.

"That's a sensitive region for developing hearing loss," said Richard Salvi, director of the Center for Hearing and Deafness at the University at Buffalo. "The longer the duration, the more serious it is."

Gruenler concedes that permanent hearing damage is possible if someone were exposed to the sound for lengthy periods.

But he said the high-pitched tone is intended to only be used for a few seconds at a time. Sound Off...What do you think? Join the discussion.


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