NYTimes -- The Sound of Things to Come

The Hypersonic Sound System - a guy named Norris has invented a device that beams sound like a laser that only you can hear.

In December, the editors of Popular Science magazine bestowed upon HSS its grand prize for new inventions of 2002, choosing it over the ferociously hyped Segway scooter. It is no exaggeration to say that HSS represents the first revolution in acoustics since the loudspeaker was invented 78 years ago -- and perhaps only the second since pilgrims used ''whispering tubes'' to convey their dour messages.

Imagine walking by a soda machine (say, one of the five million in Japan that will soon employ HSS), triggering a proximity detector, then hearing what you alone hear -- the plink of ice cubes and the invocation, ''Wouldn't a Coke taste great right about now?'' Or riding in the family car, as the kids blast Eminem in the back seat while you and the wife play Tony Bennett up front. Or living in a city where ambulance sirens don't wake the entire neighborhood at 4 a.m. Or hearing different and extremely targeted messages in every single aisle of a grocery store -- for instance, near the fresh produce, ''Hey, it's the heart of kiwi season!''

As night must follow day, there are Defense Department applications. Norris and A.T.C. have been busy honing something called High Intensity Directed Acoustics (HIDA, in house jargon). It is directional sound -- an offshoot of HSS -- but one that never, ever transmits Handel or waterfall sounds. Although the technology thus far has been routinely referred to as a ''nonlethal weapon,'' the Pentagon now prefers to stress the friendlier-sounding ''hailing intruders'' function.

In reality, HIDA is both warning and weapon. If used from a battleship, it can ward off stray crafts at 500 yards with a pinpointed verbal warning. Should the offending vessel continue to within 200 yards, the stern warnings are replaced by 120-decibel sounds that are as physically disabling as shrapnel. Certain noises, projected at the right pitch, can incapacitate even a stone-deaf terrorist; the bones in your head are brutalized by a tone's full effect whether you're clutching the sides of your skull in agony or not. ''Besides,'' Norris says, laughing darkly, ''grabbing your ears is as good as a pair of handcuffs.''