http://www.technovelgy.com/ct/Science-Fiction-News.asp?NewsNum=376Hypersonic Sound (HSS) technology does for sound what lasers did for light - provide a far more focused stream of energy over a greater distance with less dispersion. Inventor Woody Norris (shown below with his invention) has received several awards for the idea, including a Grand Prize for inventions from Popular Science: the Segway took second that same year. He was awarded the $500,000 Lemelson-MIT prize this past week.
In a recent demonstration at the American Technology Corporation, the speaker (shown above) was pointed at someone one hundred yards away. The listener heard the sound as if through headphones - despite the ambient noise from a nearby freeway - and people two feet to either side heard nothing. Sound from an HSS speaker can travel up to 150 yards without distortion or loss of volume; anyone outside the beam path hears nothing.
Here's how it works:
The piezoelectric transducer emits sound at frequencies above the human ear's 20,000-cycle threshold. Unlike low-frequency waves, the high-frequency signals don't spread out as they travel through air. Yet they do interact with the air to induce a related set of ultrasonic waves. These waves combine with the original waves, interfering to create an audible signal, focused into a beam.
(From Hypersonic Sound)
Among the many planned applications:
-Laptop speakers that only the user can hear
-Grocery store displays heard only by the person standing directly in front of them
-Entirely separate sound for front seat passengers and for those in the rear seats
-Workers on the flightline on aircraft carriers
-Life guards could warn individual swimmers at noisy pools
Cirque de Solei is considering using it to beam instructions to trapeze artists.
http://www.woodynorris.com/Articles/TechnologyReview.htm (for more information)***
And while we're at it, here's something else on speakers:
http://www.technovelgy.com/ct/Science-Fiction-News.asp?NewsNum=383Flexible Fabric Speakers Are ComingA Korean research firm has announced that it has developed a technology for the mass production of sound speakers that are as flexible as fabric. "This product will cause revolutionary changes in how speakers will look in the future," said Koh Seok-geun, president of PNI. "It took four years of studies after we initially developed the technology to make it available for mass production."
The speakers are made with a kind of plastic that is studded with electrodes; PNI researchers used plasma on the electrodes to get them to stick to the plastic. Just cut out any size piece of the fabric and attach it to an amplifier with a wire - drape your new speaker over an object, hang them like curtains, or put them in a picture frame. You could even make a cheap suit coat for hawking your wares at trade shows.
However, Pimp My Ride enthusiasts should note that this miracle fabric speaker cannot be installed on the back seat of your hoopty for awesome bass sound. The speakers can only support sounds in the upper end of the register; it cannot emit the bass sound you need.
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