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Natural Science Forum / Physics / Acoustics / July 2007Highly Directional Audio Paper?
I'd like to see this paper, anyone now how to locate it? Mike Dr. Joseph Pompei wins Technology Review's Award for Audio Spotlight Directional Sound Technology The Audio Spotlight system uses nonlinearly propagating ultrasound to create highly directional beams of sound in mid-air, which can be "shone" and "directed" much like light. Dr. Pompei was the first in the world to develop the mathematics and advanced engineering that allowed sound to be created literally from thin air with sound quality and reliability rivaling traditional loudspeakers. He presented his first paper and demonstration in 1998 to the Audio Engineering Society, and was met with a standing ovation from the world's top audio professionals. Once the audio industry was shown that such a system could actually work - and once Pompei published a paper showing exactly how, several other groups have done their best to copy the device, but none have succeeded. "I'm happy that Technology Review correctly recognized me as the true inventor of the technology," says Pompei. > The Audio Spotlight system uses nonlinearly propagating ultrasound to > create highly directional beams of sound in mid-air, which can be "shone" > and "directed" much like light. Beams of *ultra*sound. And what damn use is that to anyone ? Graham On Jul 25, 6:10 am, Eeyore <rabbitsfriendsandrelati...@hotmail.com> wrote: > > The Audio Spotlight system uses nonlinearly propagating ultrasound to > > create highly directional beams of sound in mid-air, which can be "shone" [quoted text clipped - 3 lines] > > And what damn use is that to anyone ? You can hear the demodulated result from nonlinearities. They modulate the untrasound with what they want you to hear and point the beam at you. You can hear the sound but the person beside you can't. The sound sounds as though it is right inside your head. These systems are being deployed with police for riot control and other situations where the cops may want to talk to one person and not let another hear. > On Jul 25, 6:10 am, Eeyore <rabbitsfriendsandrelati...@hotmail.com> > wrote: [quoted text clipped - 13 lines] > situations where the cops may want to talk to one person and not let > another hear. So those people who complain about the voices in their head that are beamed by the government -- they're not kooks after all? This would explain why the tinfoil hats don't seem to help much.  SignatureTim Wescott Control systems and communications consulting http://www.wescottdesign.com Need to learn how to apply control theory in your embedded system? "Applied Control Theory for Embedded Systems" by Tim Wescott Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html > So those people who complain about the voices in their head that are > beamed by the government -- they're not kooks after all? > > This would explain why the tinfoil hats don't seem to help much. They can't afford good sound deadening foam to line their foil beanies. SignatureService to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida > > On Jul 25, 6:10 am, Eeyore <rabbitsfriendsandrelati...@hotmail.com> > > wrote: [quoted text clipped - 18 lines] > > This would explain why the tinfoil hats don't seem to help much. It sure would make a good way to "Gas Light" someone. > > > The Audio Spotlight system uses nonlinearly propagating ultrasound to > > > create highly directional beams of sound in mid-air, which can be "shone" [quoted text clipped - 11 lines] > situations where the cops may want to talk to one person and not let > another hear. *ARE* being deployed ? Any evidence for that ? I doubt you can steer any ultrasound beam that accurately anyway. Graham >> The Audio Spotlight system uses nonlinearly propagating ultrasound to >> create highly directional beams of sound in mid-air, which can be "shone" [quoted text clipped - 5 lines] > > Graham See http://holosonics.com/press.html for some >advertised< uses. Mike >>> The Audio Spotlight system uses nonlinearly propagating ultrasound to >>> create highly directional beams of sound in mid-air, which can be "shone" [quoted text clipped - 8 lines] >See http://holosonics.com/press.html for some >advertised< uses. > Mike You will note _where_ it was invented ;-) ...Jim Thompson | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | America: Land of the Free, Because of the Brave > I'd like to see this paper, anyone now how to locate it? > [quoted text clipped - 5 lines] > The Audio Spotlight system uses nonlinearly propagating ultrasound to > create highly directional beams of sound in mid-air, I can't help you with the paper. However this technology is no new. The high intensity ultrasound is modulated by amplitude. It is demodulated in the air due to the thermal nonlinearities, so you can hear the sound. The main problem is that the required intensity of the ultrasound is too high to meet the safety requirements. So this technology can't be deployed for the general purpose use. Vladimir Vassilevsky DSP and Mixed Signal Consultant www.abvolt.com > I'd like to see this paper, anyone now how to locate it? > > Mike > > Dr. Joseph Pompei wins Technology Review's Award > for Audio Spotlight Directional Sound Technology Don't know about that paper but you might also check out: < http://www.atcsd.com/pdf/HSSWHTPAPERRevE.pdf > Later... Ron Capik NJ Pinelands Cultural Society < www.AlbertHall.org > -- > I'd like to see this paper, anyone now how to locate it? > [quoted text clipped - 15 lines] >device, but none have succeeded. "I'm happy that Technology Review correctly >recognized me as the true inventor of the technology," says Pompei. it might be available from aes.org, but they may take money from you for downloading articles martin On 7/25/07 5:52 AM, in article 653b6$46a74794$18d6b40c$17701@KNOLOGY.NET, > I'd like to see this paper, anyone now how to locate it? > [quoted text clipped - 15 lines] > device, but none have succeeded. "I'm happy that Technology Review correctly > recognized me as the true inventor of the technology," says Pompei. Although I have not read it any detail, there is a Wikipedia article on Parametric Loudspeakers. It should not be surprising that high intensity ultrasound can generate audible difference frequencies. Unfortunately, the nonlinear mathematics required to describe a nonlinear process is complicated and non-intuitive. While at first blush this complexity is a deterrent to working in the field, it leaves much opportunity for invention and novelty. Bill SignatureIraq: About three Virginia Techs a month > I'd like to see this paper, anyone now how to locate it? > Dr. Joseph Pompei wins Technology Review's Award > for Audio Spotlight Directional Sound Technology Sorry; we need a journal reference. But I recognize it as "parametric sonar". It took me a while to resolve what is being talked about since authors use different terminologies for the same facts. Two ultrasound beams from the same sender cross at some remote point in space. Both beams are amplitude modulated with the same audio signal. The ultrasound ampitude of the combined beam is locally doubled such that nonlinear presssure vibrations occur at the modulated audio rate, whereby audible sound emerges in the coss beam zone. That audio is a traveling wave, and the wave propagation direction is the same as the ultrasound beam. So in effect, a wave of audble sound has been generated with very specific directionality; the same as that of the ultrasound beams that formed the audio. A lot of seculation and half-truths have emerged since the invention of parametric sonar. The human imagination provides wonderful entertainment...as is evident in the following words: > The Audio Spotlight system uses nonlinearly propagating ultrasound to > create highly directional beams of sound in mid-air, which can be "shone" [quoted text clipped - 8 lines] > device, but none have succeeded. "I'm happy that Technology Review correctly > recognized me as the true inventor of the technology," says Pompei. and they all lived happily after. Ang. C. >> I'd like to see this paper, anyone now how to locate it? >> Dr. Joseph Pompei wins Technology Review's Award [quoted text clipped - 39 lines] > > Ang. C. >Hi Ang, I note a bit of sarcasm in your response :-). But there does seem to be real end users of the product. See http://holosonics.com/press.html for some >advertised< users. The short article in Scientific American (seemed) as if it only had one driver, anyone differ with that? Mike >>Hi Ang, > I note a bit of sarcasm in your response :-). why not.. > But there does seem to be real end users of the product. > See http://holosonics.com/press.html for some >advertised< users. > The short article in Scientific American (seemed) as if it only had one > driver, anyone differ with that? This particular non-linearity, aka cross modulation, is a progressive effect, with the greater nonlinearity occurring at the greater distance before diminished amplitude reverts to linear propagation, before vanishing. The original concept, ancient history now, used crossed or crossing beams at first, if for no other reason than simplicity and the availability of powerful transducers, I think. This is now out of research and into the production engineering and the market development phases. Ang. C. > I'd like to see this paper, anyone now how to locate it? > > Dr. Joseph Pompei wins Technology Review's Award for Audio Spotlight > Directional Sound Technology Oh, hell - I thought you were talking about a piece of paper which, when you apply a signal, emits sound. )-; Thanks, Rich >> I'd like to see this paper, anyone now how to locate it? >> [quoted text clipped - 6 lines] > Thanks, > Rich Well Rich, I did think about rephrasing the subject line, but looks like the idea got through. :-) Mike >>> I'd like to see this paper, anyone now how to locate it? >>> [quoted text clipped - 6 lines] > Well Rich, I did think about rephrasing the subject line, but looks > like the idea got through. :-) Oopps! Sorry I didn't provide a smiley to indicate that my saddy was intended to be humourous. ;-) [then again, sometimes I think I'm the only one who gets my humour - should I take a poll? >:-> ] ["YES! SHUT THE F**K UP!!!!!!" I hear you cry. Oh, well )-; ] ;-) Cheers! Rich >>>> I'd like to see this paper, anyone now how to locate it? >>>> [quoted text clipped - 17 lines] > Cheers! > Rich Rich, I'm fine with you, I get your humour, sometimes I even enjoy it :-) Mike Here's a smiley face to make up for the one you think you missed :-) > "Rich Grise, Plainclothes Hippie" <eatmyshorts@doubleclick.net> wrote in >>> "Rich Grise" <rich@example.net> wrote in message [quoted text clipped - 21 lines] > Mike > Here's a smiley face to make up for the one you think you missed :-) Hey, one is infinitely more than zero. ;-D Thanks! Rich |
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