JJkizak Posted January 30, 2009 Share Posted January 30, 2009 Check this out. http://www.ted.com/index.php/talks/woody_norris_invents_amazing_things.html Quote Link to comment Share on other sites More sharing options...
soundbound Posted January 30, 2009 Share Posted January 30, 2009 Amazing technology. That's going to completely change future audio. Quote Link to comment Share on other sites More sharing options...
Don Richard Posted January 30, 2009 Share Posted January 30, 2009 This system uses a narrow-angle ultrasonic carrier wave with audio modulation. Another ultrasonic beam with no modulation is directed so as to cross paths with the modulated one. At that point in space, beat frequencies occur within the audible range of human hearing. No audio is heard away from the focal point. However, it isn't hi-fi, at least not for now. Quote Link to comment Share on other sites More sharing options...
seti Posted January 30, 2009 Share Posted January 30, 2009 The Japanese have taken this a step further. They have a way to beam the music and use your skull to make the sound appear to be in your head which it is. They use this in vending machines. You walk by and they talk to you. Scary..... Quote Link to comment Share on other sites More sharing options...
Edgar Posted January 30, 2009 Share Posted January 30, 2009 This system uses a narrow-angle ultrasonic carrier wave with audio modulation. Another ultrasonic beam with no modulation is directed so as to cross paths with the modulated one. At that point in space, beat frequencies occur within the audible range of human hearing. No audio is heard away from the focal point. However, it isn't hi-fi, at least not for now. AFAIK, it's not beat frequencies, which is a result of linear mixing, but intermodulation distortion, which is a result of nonlinear mixing. Air is only slightly nonlinear, so the carriers have to be way up around 130+ dB SPL for this technique to work. Nobody knows the effects of 130 dB SPL ultrasonic waves upon humans, but I'm not thrilled about being bombarded by them. Quote Link to comment Share on other sites More sharing options...
Don Richard Posted January 30, 2009 Share Posted January 30, 2009 AFAIK, it's not beat frequencies, which is a result of linear mixing, but intermodulation distortion, which is a result of nonlinear mixing. Air is only slightly nonlinear, so the carriers have to be way up around 130+ dB SPL for this technique to work. Nobody knows the effects of 130 dB SPL ultrasonic waves upon humans, but I'm not thrilled about being bombarded by them. It's the beat frequencies that you hear with this system: http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/beat.html http://www.dxarts.washington.edu/~eskang/larynxians/image/uss.pdf Quote Link to comment Share on other sites More sharing options...
Edgar Posted January 30, 2009 Share Posted January 30, 2009 It's the beat frequencies that you hear with this system: Nope. It's intermodulation: "Ultrasound audio technology is based on this non-linear property of air, creating interference patterns between tones in the ultrasonic frequency range (beyond 20 KHz) lower difference tones can be generated in the audio range (between 20 Hz and 20 KHz)." It's an important difference. Beat frequencies do not actually exist. They are perceived by our ears (well, actually, our brains), but if you do a spectral analysis upon the sum of two linearly mixed tones, you find only the original two tones. Intermodulation products DO exist. If you do a spectral analysis upon the sum of two nonlinearly mixed tones, you find the original two tones, plus their sum and difference (and possibly higher order products, depending upon the nature of the nonlinearity). It is all explained by trigonometric identities. Quote Link to comment Share on other sites More sharing options...
Don Richard Posted January 30, 2009 Share Posted January 30, 2009 Nope. It's intermodulation: Above 145 dB SPL, that is correct. Audio reproduction by IM distortion... sounds like something invented by BoSe.[] Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted January 30, 2009 Share Posted January 30, 2009 I did not hear anything from the demo. Quote Link to comment Share on other sites More sharing options...
djk Posted January 31, 2009 Share Posted January 31, 2009 HE came up with the idea of the linear tracking tonearm in 1959? The Rabco SL8E was submitted for patent in 1954 http://www.google.com/patents?id=3KpIAAAAEBAJ&pg=PA1&dq=2915315&source=gbs_selected_pages&cad=0_1#PPA1,M1 Which in turn references a 1940 patent: http://www.google.com/patents?id=YvhvAAAAEBAJ&pg=PA1&dq=2254412&source=gbs_selected_pages&cad=0_1 And of course, the ultrasonic directional speaker is not a new idea either: http://www.google.com/patents?id=Lmo5AAAAEBAJ&dq=4823908 Quote Link to comment Share on other sites More sharing options...
soundbound Posted January 31, 2009 Share Posted January 31, 2009 He surely sees himself as a great inventor. Quote Link to comment Share on other sites More sharing options...
SWL Posted January 31, 2009 Share Posted January 31, 2009 He surely sees himself as a great inventor.He parties with Ken. Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted January 31, 2009 Share Posted January 31, 2009 He surely sees himself as a great inventor.He parties with Ken. He didn't eat breakfest either. Quote Link to comment Share on other sites More sharing options...
soundbound Posted January 31, 2009 Share Posted January 31, 2009 HE came up with the idea of the linear tracking tonearm in 1959? The Rabco SL8E was submitted for patent in 1954 http://www.google.com/patents?id=3KpIAAAAEBAJ&pg=PA1&dq=2915315&source=gbs_selected_pages&cad=0_1#PPA1,M1 Which in turn references a 1940 patent: http://www.google.com/patents?id=YvhvAAAAEBAJ&pg=PA1&dq=2254412&source=gbs_selected_pages&cad=0_1 And of course, the ultrasonic directional speaker is not a new idea either: http://www.google.com/patents?id=Lmo5AAAAEBAJ&dq=4823908 Is this invent inventor being inventive about inventing these inventions he states he invented? Quote Link to comment Share on other sites More sharing options...
Don Richard Posted February 1, 2009 Share Posted February 1, 2009 Is this invent inventor being inventive about inventing these inventions he states he invented? Let's take inventory. Quote Link to comment Share on other sites More sharing options...
Randyman Posted February 2, 2009 Share Posted February 2, 2009 Hey there Kenny[] Quote Link to comment Share on other sites More sharing options...
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