Riktat Ljud, hur funkar det?

Att rikta ljud fungerar alldeles utmärkt. Här har du ett intressant klipp med uppfinnaren själv:
Länk till klipp

Someone referred me to this talk. One of my specialties is the acoustic and audio design of museums and exhibit spaces. We have extensive experience evaluating and implementing many types of focused and non-focused audio delivery systems. While the directional focus of Mr. Norris' product and others like it is certainly impressive, it pretty much stops there for any real application of quality. The frequency response is very limited and most things, except bird chirps and soda can openings sound pretty lousy (ask him to demo full-range music and you'll see what I mean). Volume also is limited, which means in a museum or retail mall where there are a lot of screaming kids, you can't just keep turning it up until it is intelligible over the ambient sound level. Even the directivity can be a problem, since it amounts to the equivalent of shooting a laser beam in a room full of mirrors. Because the energy wave is of such great intensity (which is why ,if you're outdoors with no obstructions, you can hear this a mile away) any part of the 'beam' that makes it past the intended listener will just continue to reflect around the room and not lose energy like a typical loudspeaker does over distance. Finally, because the carrier wave is of such short wavelength, traditional materials for absorbing sound will not work. In our lab, we tried aiming Mr. Norris' product at 12" of fiberglass insulation and it actually reflected with only a slight energy loss!

So, in summary, while I'm sure that this has targeted uses in less-critical and quality applications and we certainly can support that, for more serious environments, this is a cool party trick at best.

-Steve Haas
SH Acoustics

Såg på TV om ett par högtalare som man kunde rikta till en enskild punkt, t.ex en soffgrupp. Det ljudet hördes bara i den soffan, och inte runt om.

Min fråga är då, hur fan kan man rikta ljudet? Allt jag lärt mig är det som sagts på fysiklektionerna på gymnasiet, och detta motsäger ju allt jag lärde mig ^^