Weapon Sends Message That's Loud & Clear

By Peter Pae, Times Staff Writer

SAN DIEGO - The shrill cry of a baby can be one of the most annoying sounds of daily life, but it is music to Pentagon strategists.

An electronics company, American Technology Corp., has turned the wail of a baby into a weapon that fires "sonic bullets," narrow beams of noise that exceed the human threshold of pain. It can incapacitate people or compel them to flee.

"It gives you the equivalent of an intense migraine headache," said Elwood G. Norris, the company chairman and inventor of the device. "It's just totally disabling."

Norris uses 50 different sound tracks, or sonic bullets, in his new weapon. For instance, it plays backward the sound of a baby crying at 140 decibels, 0r 20 decibels above the threshold of pain. The noise-level is similar to that of a passenger jet taking off. Pentagon officials see many uses for Norris' invention, such as controlling unruly crowds, foiling hijackers and keeping potential suicide bombers at bay. A commercial variant also may have applications in movie theaters, vending machines and retail stores.

The sound technology is not the first time that Norris, has made waves. A prolific inventor, he developed and patented a Doppler system that is a key component of ultrasonic imaging technology. He also invented the first digital sound-recording device, as well as a microwave radar that can detect plastic land mines.

The acoustic weapon is categorized by the Pentagon as nonlethal, but it could damage hearing or cause psychological harm. It is one of the more innovative devices among the nonlethal weapons the military is developing, analysts said.

"They're very intrigued by these nonlethal weapons," said Loren Thompson, a defense analyst with the Lexington Institute think tank in Arlington, VA. "Some acoustic weapons are so powerful that they can knock you out."

ACOUSTIC TECHNOLOGY

Weapons makers have been developing a nonlethal arsenal for decades, but new advances in microwave and acoustic technology as well as post- Sept. 11 security concerns have raised interest in such weapons.

The signal emitted by the acoustic weapon can penetrate any opening and bounce off surfaces before reaching the intended targets. In Afghanistan, it could have been used to drive out enemy soldiers holed up in caves and buildings.

It could help an airline pilot fend off hijackers without harming the aircraft or bystanders. And it could help military ships protect their perimeters in port. (snips) Despite years of research on sound-harassment weapons, Pentagon officials say this is the first time soldiers will be able to direct the harassing should at a particular individual or target.

A significant feature of the device is the fact that the person standing behind or next to the emitter can't heard the sound. It is heard only by the person who is in the sound emitter's line of fire. (snips) American Technology's weapon is based on a beaming technology that Norris has been trying to perfect for more than seven years. Known as the hypersonic sound system, it also is creating a major buzz within the commercial acoustics industry.

Unlike a traditional speaker, which produces sound by vibrating the membranes of a woofer or a tweeter, small crystal wafers project a beam of sound across a room like a spotlight. The emitters are semiconductors used by Norris in a configuration that produces focused sound waves.

The device sends out two ultrasonic signals that produce sound only when they hit an object or a person.

An emitter pointed at a wall will produce a sound that seems to be coming from the wall, not the emitter. However, a person who is not in the line of the beam will not hear anything unless the beam has been bounced off the wall.

In a recent test of the device in the company's parking lot, a reporter stood about 100 feet from the emitter and could hear a radio broadcast as though it were coming from within the ear. Norris then pointed the emitter at a nearby window and it seemed as though the sound were coming from within the building. (snips) After seven years of research and development, American Technology recently received Food and Drug Administration approval to begin marketing the product. The FDA determined that the new sound technology does not have adverse health effects, Norris said.

The weapons version, which does not require FDA approval, uses high- intensity emitters specially designed for the Pentagon. (snips) Stereo-equipment manufacturers also are looking at the technology. The system would allow individuals in a car to listen to different music without using headphones, and movie theater operators would be able to project the system off the screens, giving the audience the illusion that the sound is coming from the actors' mouths. (snips) A simple version of the commercial system will sell for $200 to $300.

The sound technology is the future for us," Norris said.