new technology

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I wonder how he could get a patent for this device at all since the idea isn't that new.
I could imagine that such devices might be useful for special announcement systems but I wouldn't use someting like that for listening to music (I wonder why he used white noise and not music for his demo !).

Furthermore the effect of loud ultrasonics on human hearing is not fully known yet.


"...The emitter — an aluminum square — was hooked up by a wire to a CD player. Norris switched on the CD player..."

Just for a laugh, I wonder how can any transducer which is hooked to a cd player produce ultrasonic frequencies, when cd red book standard is 22000 Hz max. ( 20000 HZ practically).;)

It is a fact that musical instruments produce frequencies and harmonics which are far beyond "the limits" of human hearing, but most attempts to include those frequencies on systems for replaying recorded music were usually regarded to as "audiophile snake oil".

There is really no such thing called "AN INVENTOR"
An inventor is a person who finds a way to reproduce and control a natural phenomenal : ultrasonics had always influenced the way we here music, but it was never really clear exactly how : We should hope that such inventions as Mr. Norris "Soundless Sound System" will help finding answers.
That's exactly how he does it. I think you’re referring the same technology you heard about several years ago – they’ve been at this for a while now. If you wanted to reproduce a 1000Hz sine wave, you’d transmit an ultrasonic beam at a higher carrier frequency; say 200,000Hz and one at 201,000 Hz. The beams are of very high intensity and make use of the non-linearity of air at very high pressures to heterodyne or mix the two ultrasonic tones, producing sum and difference tones, one at 1000Hz that you can hear and one at 401,000Hz that you probably can’t. Just like AM radio. I have read concerns about the safety of long-term exposure to high intensity ultrasounds (and these must be extremely intense to achieve enough non-linear response in the air for efficient heterodyning). And we know nothing about the linearity (distortion) of the baseband audio products.

Check out their website at
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