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Music Media

Targeted Sound Beams 166

Posted by michael from the rumble-strip dept.
Mr_Kcleen writes: "Wired has a story on using sound beams targeted to only one person. They discuss various uses, from musical performances to possible weaponization." This is another one of those ideas that are right around the corner, really, honest.
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Targeted Sound Beams

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  • Possible weaponization? (Score:5, Funny)

    by JohnyDog ( 129809 ) on Sunday February 24, 2002 @08:16AM (#3060233)
    I only hope that this won't be adopted by RIAA.

  • great (Score:1)

    by nempo ( 325296 )
    one step closer to the reality of that game where the bad guy named "Dollar bill" wants to build a artificial moon and use it for 24/7 advertising.

  • ahh! (Score:4, Funny)

    by Goofy Gavin ( 561311 ) on Sunday February 24, 2002 @08:22AM (#3060240)
    i hope that explains those voices that keep telling me to horde my precious bodily fluids.

  • For more information...... (Score:3, Informative)

    by Mattygfunk ( 517948 ) on Sunday February 24, 2002 @08:25AM (#3060241) Homepage
    The New York Times [nytimes.com] is also covering the article [nytimes.com] (free reg) or you could just go to The Audio Spotlight's [mit.edu] home page for a more detailed account of their technology.
  • when they invented earhpones...
  • Am I the only one thinking of ways to manipulate people into doing things silly? Does anyone remember that scene from 'Real Genius' where they put the radio in that guy's braces and had him believe he was talking to God? This would make things so much simpler...you wouldn't have to mess around with anyone's braces...just point and shoot and blammo instant God.
    • One of the funniest scenes in the past few years of the Simpsons has to be when Ned and Homer are in the casino in Vegas, and Ned is having moral issues with gambling. So, he looks to the heavens, and asks if he should gamble.

      Of course, in Las Vegas casinos the ceilings are absolutely covered with a/v packages to watch patrons, so the security guy mutters in a low voice 'keep gambling'. To which Ned proceeds to spend a huge wad of money.

      This 5 second scene pokes fun at so many things at once, I'm always in stitches.

  • brilliant! (Score:5, Funny)

    by Goofy Gavin ( 561311 ) on Sunday February 24, 2002 @08:33AM (#3060247)
    every day, technology brings us a little bit closer to being able to make our younger siblings think that they've gone insane :D
    • every day, technology brings us a little bit closer to being able to make our younger siblings think that they've gone insane :D

      Actually, this is in fact one of the uses the technology has. I'm surprised this story wasn't included in the article...

      The researchers working on this project have offices on the top floor of the Media Lab's building, right next to the central atrium open to the floor five stories below. Apparently they would enjoy leaning over the railing and pointing the Audio Spotlight at unsuspecting people down below, then playing the sounds of breaking glass. The hapless victims would then undoubtedly find themselves quite confused as they looked around to make sure they hadn't stepped on and broke something...

  • Finally science has reached it's peak. A surefire way to get the beer guy's attention at your next baseball game. On a serious note, hasn't the pentagon being looking into ultrasound devices for crowd control and similar applications for a LONG time (say 20+ years?) I seem to recall a Discovery Channel special on that a while back.

    General - Why we could make a devestating weapon out of that!
    Inventor - It's a tortilla maker. . .
    General - Why yes, but think of the scientific principles it displays!
    Inventor - It's a cast iron tortilla maker. .
    General - We need 800,000 by next week. How does 300$ per unit sound?
    Inventor - The Freedom Flattener 3000 will be operational by tomorrow General!

    • Re:cold one over here! (Score:5, Funny)

      by Cyclopedian ( 163375 ) on Sunday February 24, 2002 @09:05AM (#3060302) Journal
      A surefire way to get the beer guy's attention at your next baseball game.

      This might be a bad idea, since tons of other people would be pointing the same device at the poor beer man. The beer man would be overloaded with requests and ultimately crack under the sonic pressure. Insanity by sonic buffer overflow...what a way to go. =)

      -Cyc

    • I'd just like to point out that there's a reason things cost so much when the military buys things.

      In the example, you'd have to completly document everything about that tortilla maker:
      Where the iron was dug out of the ground. (and probably which shift.)
      Where the ore was smelted and refined. (and ditto)
      Where it was cast. (and ditto.)
      Transportation...

      All that ISO-8002 (or whatever) paperwork costs much money. $500 hammers make a nice target for senators who want to look good with "Golden Fleese" awards, but there's a reason they cost that much compared to running down to the hardware store.

      • When I worked in defense contracting, there were about 2 guys doing paperwork and QA for every guy working. And this was a company ran by veterans and retirees who were _not_ going to screw the service, do a half-assed job, or run the costs up any higher than necessary to do the job right and according to regulations. It was the regulations that ran the costs up, mainly the regulations Congress enacted to make sure no one was screwing the service...

  • Pompei's MIT website (Score:3, Informative)

    by JPriest ( 547211 ) on Sunday February 24, 2002 @08:35AM (#3060251) Homepage
    Pompei's website hase more detailed information of this here: http://web.media.mit.edu/~pompei/spotlight/ here is a brief description from the site. Technology: Because it is impossible to generate extremely narrow beams of audible sound without extremely large loudspeaker arrays, we instead generate the sound indirectly, using the nonlinearity of the air to convert a narrow beam of ultrasound into a highly directive, audible beam of sound. The device transmits a narrow beam of ultrasound (blue), which, due to the inherent nonlinearity of the air itself, distorts (changes shape) very slightly as it travels. This distortion creates, along with new ultrasonic frequencies, audible artifacts (green) which can be mathematically predicted, and therefore controlled. By constructing the proper ultrasonic beam, this nonlinearity can be used to create, within the beam itself, an audible sound beam containing any sound desired. This is presently done in real-time using low cost circuitry, a specially designed amplifier, and transducers developed at MIT specifically for this project.

  • 60 kHz? (Score:2, Interesting)

    by tlotoxl ( 552580 )
    Is all the energy converted to the audible range or do we get weird things going on elsewhere in the spectrum? Will dogs bark and birds flee?

    Sounds like fun technology. I remember reading about it a while back, but had no idea it was being implemented in commercial projects. Portable mp3 players/discman seems like a better car solution to me, but some of the other applications are intriguing. Time to get myself to Tokyo.

    • Re:60 kHz? (Score:2, Funny)

      by red5 ( 51324 )
      A dogs hearing range tops out at 47kHz First link I could find [doctordog.com]
      So Spot should be just fine with the system.
      • Too bad none of the technical papers are online to read for the details; if the audio were centered at 60kHz, as is sort of implied, I would think we could expect the range to actually be from 50kHz-70kHz -- or is it instead from 60-80kHz? Or double sideband from 40-80kHz?
  • And technology has now put yet another profession out of business. And how do you expect ventriloquists to make a living now, huh?
  • Parabolic microphones and speakers have been around (commericially, even) forever. They already pretty much do this - picking up sound in a straight line from the source from a long distance away.

    I guess this might work over a longer distance than parabolic stuff, but they haven't really shown that. So basically, they have a technology that can be duplicated by taking a regular speaker as the focus surrounded by a plastic parabola.

    I wonder why they didn't bring that up in the article? Surely they've heard of it?
    • These people are actually doing something very different.
      They're taking ultra-high frequency sound which is way out of our audible range, the higher the frequency the more directional (which is why you dont need to worry too much about where your sub-woofer goes) and recreating audible sound by causing what is known as "beats" in two or more similar high frequency sound beams (guitarist will be familiar with beats, as they are very noticeable when tuning strings without a tuner). These beats are obviously at such a high rate when caused by high freq sounds (60khz!!) that they themselves create audible tones.
      If you need an example of how directional and effective high freq sound is, there have been numerous problems in horse racing over the last decade with people mounting high-freq sound emitting devices in binocculars which are then targetted at specific horses, causing them to freak out... Several people have been caught out in Australia with such devices.
      So, high frequency sound will not travel as far as low freq, but at 60khz, you can put as much power into it as you like and therefor push it as far as you like without annoying to many people, which makes it a hell of a lot more effective than normal "parabolic" cones or horns.
      • the higher the frequency the more directional

        Why is that? I've always wondered...


        • the higher the frequency the more directional

          Why is that? I've always wondered...

          Higher frequencies have shorter wavelengths (if the wave propogates at a given velocity, that means it covers a computable distance in a given amount of time. If the frequency is higher (more cycles per unit of time) the waves will be shorter (more cycles per unit of distance), thus higher frequency = shorter wavelength).

          Higher frequencies are also higher energies. To cycle at a higher frequency, whatever carries your wave has to move faster, which means more energy.

          So now your question becomes: why are higher frequencies / shorter wavelengths / higher energies more directional. There are all sorts of ways of looking at this. For example, ask yourself which is more directional, a low energy falling-leaf or a high energy cannon-ball? Or think about a person on foot vs. a city bus; the person, being smaller, doesn't "defract" around things like parks, while the larger bus does. Or think about throwing a cotton ball vs. throwing a marble. The cotton ball is larger and lower energy while the marble is smaller and higher energy.

          Thinking like this should at least give you a feel for the effect (which is, after all, a rule of thumb rather than an absolute law). None of them is quite the whole story, but they should help you visualize what's generally going on.

          -- MarkusQ

          • The location from which a sound is originating is determined in part by pinna cues. The pinna is the visible fleshy outer part of the ear. Higher frequencies may reflect off the pinna before entering the ear canal. This colors the sound, giving clues to its origin. A person who is blindfolded and has her pinna folds filled with clay, will be able to tell if a sound is coming from the left or the right, but will not point to the source with any great accuracy. Sound waves typically pass through surfaces that are smaller than their wavelength. Lower frequencies pass through the pinna. Without reflected sound, its origin is ambiguous.
            • The location from which a sound is originating is determined in part by pinna cues. The pinna is the visible fleshy outer part of the ear. Higher frequencies may reflect off the pinna before entering the ear canal. This colors the sound, giving clues to its origin.

              The relationship between frequency and directionality is much more general. It applies to light, sound, and even in quantum mechanics. A low frequency wave in general is much less localized than a high frequency wave, because it is "larger". So while the shape of the ear may affect the perception of directionality of sound (I don't know, but I suspect you are correct) this would be just another example of the more general effect.

              -- MarkusQ

              • To be precise, it's a relationship between _wavelength_ and directionality. Waves diffract around the edges of the antenna, parabolic reflector, or lens, and so you cannot form a tight beam unless the aperture is much larger than a wavelength.

                wavelength * distance = k * aperture * resolution

                or

                resolution = wavelength*distance/(k*aperture)

                "Aperture" is the effective diameter of the antenna/parabolic reflector/primary lens.

                "Resolution" here means the diameter of the best focused spot if transmitting, or the closest together point sources a receiver (radar, telescope, directional mike) can resolve. This is a somewhat fuzzy definition, since the power density of the transmitted beam tapers off from the center...

                "k" is a constant, depending on how you define resolution (e.g., do you need a head-sized spot at full power and don't care about whether audible sound bleeds over several feet away, or do you need to ensure that no one else can hear it at all). Under various definitions, "k" can be 1/3 to 3.

                So for sound at 100 Hz (bass, but not a really deep bass):

                wavelength = speed/frequency ~= 700mph/100hz = (1027 ft/sec)/(100/sec) ~= 10 feet

                So a 10 foot speaker can focus the output into a spot 100 foot wide at 100 feet. If you filter the bass, at 1KHz, which is center of the voice band, you get a 10 foot spot at 100 foot -- from a ridiculously large speaker. To focus down to where just one person hears the sound, you'd need a 10 foot speaker only 10 feet away -- you might as well put a smaller speaker around his head.

                Ultrasound improves these numbers because the wavelength is smaller. At 60 KHz, wavelength is 1/60th of a foot, so a 1 foot speaker could send just to one person up to about 60 foot. Of course, you are depending on non-linear interactions in his skull to "rectify" the high frequency carrier and extract the audible band signal.

                Note that you can synthesize an enormous aperture from an array of small elements, if you can keep them precisely positioned and synchronized. So by covering the entire ceiling of the Senate chamber with little speakers, you could make _only_ Jesse Helms hear voices (if he's got any hearing left). This seems rather excessive. With the ultrasound scheme, maybe you could hide the rig in a briefcase and literally put the voices in his head from the gallery. Much more fun that way, eh?

                Oh darn, yet another thing for their security to check for...
    • What they are doing is significantly different
      to directing sound with a parabolic lens.


      In its broadest sense the problem with any transmitting antenna, be it sound, light or radio frequencies, is diffraction


      For a given wavelength the smaller the space you emit the waves from the wider the angle they spread over.


      What these people have done is to use the improved diffraction characteristics of high frequency ultrasound, which diffracts far less than ordinary audio frequencies to generate audio sound literally "out of thin air" due to a nonlinear interaction within the air.


      Hats off to Mr Pompei, it sounds like a very neat system. (I couln't help the pun, sorry)

      • I understand, and agree that this is different. But you have to admit, it produces the same effect, though the device can be smaller than the necessary parabolic dish.

        Does it warrant the expense?
        • yes, because it's extremely hard to produce directional, broad-specturm sound with conventional speakers. you have all sorts of problems with delay, defraction etc.. (see previous posters expl..)
          In theory, this new process should be able to produce a relatively perfect sound quality over a large distance without causing illegal noise pollution.
    • doesnt work like that at all.. your dish + speaker to beam sound to a location doesnt work. cince it is still at slow frequencies it get's messed up and will spread from the mouth of the dish like a floodlight.... tis how sound works... hyper-frequency sound... just below radio waves, have both characteristics... act as sound, propagate like radio waves... and this is what they are using... read the article.
    • The speakers on my computer are set to direct sound at one person. I just haven't figured out how to stop the neighbors from hearing it too yet. :^)

  • Not new... (Score:2, Informative)

    by toxcspdrmn ( 471013 )
    This was reported in Scientific American [sciam.com] in 1998. I also recall seeing it in New Scientist, and on the BBC television programme, "Tomorrow's World" at about the same time.
    • Yeah, I remember seeing TW cover it. "News" eh? :-)

      The TW demonstration was pretty cool - a couple dancing in a silent ballroom and the presenter doing her bit nearby. Then she walks towards them with the mike, and a yard or two away the music appears. A pretty neat demo. (Of course, the cynics would say that you can fake it all in post-production just by adding the music to the mix, but that's unlikely given that this was the BBC's tech-news programme).

      Grab.
  • Didn't this same thing happen in Atlas Shrugged?? What next? All Engineers of the world, let's go on strike!
  • I first read this 2 years ago on howstuffworks [howstuffworks.com]. Same theory, same proposed applications, but no new ideas except for the possible weaponization - (yeah, some idiot had to think of it eventually).

    Once it solidifies though, it is definitely a cool sounding (excuse the pun) technology. Use humans only have 2 ears in fixed positions, and I've often wondered how we can locate 3 dimensional sounds using only 2 ears (do we really?). Wonder how this turns out over the next few years...

    • Yes - we do identify sound in 3d see this slashdot [slashdot.org] article for discussion of why brod spectrum sounds are easier to pinpoint.

    • Re:2 year old vapor (Score:5, Insightful)

      by fireboy1919 ( 257783 ) <rustypNO@SPAMfreeshell.org> on Sunday February 24, 2002 @09:21AM (#3060327) Homepage Journal
      Yes, we hear sound in 3d...sort of.

      For the most part, (with a few exceptions), most humans are only able to distinguish thing in front of them from things behind them, and its quite easy to prove that we can't guage distance from sound (because we don't know how loud it was at the point source).

      However, anyone can train to improve their selective listening skills and achieve more 3d awareness. Its quite a common skill among conductors, musicians, and most of all sound technicians.
      • Huh. Here's what I remember from when I took my scuba diving class, feel free to tell me why I'm wrong: I was told that people judge distance by automatically detecting the difference in time it took for the sound to reach the left vs. the right ear. Therefore, you'd be able to judge whether a sound was coming from the left or right, but NOT front or back.


        The application for scuba diving is that because sound waves travel 3 times as fast underwater, it's almost impossible to tell what direction sounds are coming from.

        • Actually, the ITD (interaural time difference) and the IAD (interaural amplitude difference) are both involved in being able to judge the angle of origination of a sound source. The IAD is the old style of stereo effect: if it's louder on the right, the sound source is on the right, and vice versa. The interaural time difference is based on the fact that since the head is ~6 inches across and the ears are ~6-7 inches apart, with sound traveling close to ~1100 feet per second will arrive at most ~1/2000th of a second apart in the right vs. left ear. Under water, with a different speed of propagation for sound vibrations of close to ~5000 feet per second, this
          difference is divided by ~4.something, so the brain which is accustomed to deciding that something is on the right or the left based on the ITD and IAD does not get enough data to be able to tell the difference. All time delays are now within 1/4th to 1/5th of all of the time delays it is accustomed to hearing and thus thinks that every noise source is coming from a cone within less than 20-30 degrees directly in front of or behind you. Nothing sounds like it is on your right or your left. (note that this is in answer to the parent post, not just the current topic).

      • and its quite easy to prove that we can't guage distance from sound (because we don't know how loud it was at the point source).

        You could prove that, if sound waves were perfectly linear. But they aren't. Sound media (such as air) are nonlinear, dispersive media, which means that sound of different frequencies propagate at slightly different speeds, meaning that wave packets will slowly disperse in air (or any other medium). If you have any familiarity with QM, it's the same principle that causes matter wave packets to disperse over time. Another example would be the dispersion of a polychromatic light pulse as it travels along an optic fiber. Since light of different frequencies travel at different speeds through anything that isn't vacuum, the light pulse will spread/smear out as it travels down the waveguide. The amount of spread depends on how far the pulse traveled.

        A computer can definitely tell the difference between a sound pulse that has traveled 1 meter and a pulse that has traveled 100 meters, even if they are the same loudness when they reach the detector. I bet at least some humans can tell the difference also.

        • Well, see, you prove it by taking a whole bunch of people and trying a wide variety of sounds at different volumes and locations and getting them to identifiy how far away the sound are.

          They won't be able to. The test have been done before, though I can't tell you where right now.
          Why don't we use phase shift or spectrum spread?

          Because it isn't a reliable indicator of anything. Different frequencies propagate at different speeds, true, but you have to know what the sound is like at the source, and about everything in between - something we do not know reliably. Did you know that a sound coming from a source on a wooden stage will usually reverberate with more of the lows than the highs? If we depended upon sound spread for distance, it would make the sound appear closer. What about audio amplification? Using pretty much any means - electrical or acoustical - the result is a phase shift and a spreading of the sound - something you would expect if the sound is farther away. Also, due to the nature of reflection, out of phase sources that meet at a wall will only reflect their in-sync portions, confusing the distance based on phase for both of them.

          What does all this show? That the interaction of sound waves with the surrounding media is so complicated that there is no way to accurately use them to guage distance with an unknown sound.

          A computer may be able to tell the difference between a computer generated pulse specifically used for distancing that has traveled 1 meter and one that has traveled 100 meters, but it wouldn't be able to know the difference between a live band heard 100 meters away and one heard 1 meter away.

          --From an acoustical engineer
          • Alright. I thought you meant "prove" in a mathematical sense, when I knew for a fact that the pulse will disperse as it travels. I assumed (incorrectly) that a person would be able to tell. I guess I shouldn't take my electrodynamics knowledge and blindly apply it to acoustics. Thanks for catching me.

  • Beat Frequency (Score:5, Interesting)

    by jafuser ( 112236 ) on Sunday February 24, 2002 @08:44AM (#3060273)
    This is actually a very simple concept, called beat frequency [everything2.com]. I guess nobody ever thought to try it on ultrasonic frequencies to recreate frequencies that are within our hearing range. You may remember beat frequency from your high school physics class, if your teacher ever demonstrated the "weird effect" you hear when you strike two very slightly different tuning forks, you'll hear both tuning forks, plus a beat frequency that is equal to the frequency difference of the two tuning forks. You also hear the effects of beat frequency if two people try to make the same tone with their voice (such as when singing duet), it almost sounds like there's a third voice in there.

    I saw a demonstration of this technology [discover.com] a few years ago at Epcot center, during the Discover Magazine Awards for Technological Innovation [discover.com]. The demonstrator held this paddle-like device with an array of metallic discs on it, and as he turned it slowly across the crowd, you'd not hear a thing until it was pointed at you. Very cool :)

    • I remember reading several years ago about using beat frequencies to generate sound in the audible range. The big problem was that to generate audible sounds using beats, the beating frequencies have to delivered at fairly high amplitudes ( >153 dBL IIRC) and it is unclear what effect high sound levels in the ultrasonic range would have on humans.

      Ever since Pompei announced his research, the beat research seems to have died.

      BTW, if anyone is interested in working with Pompei, send him an email. He is very accommodating to inquiries.
    • Well, since you mention it, I did try to do exactly this in the early 1970s.

      The plan was to try to produce really heavy bass for reggae music by beating two ultrasonic frequencies together.

      I never got it to work properly, for a lot of reasons, but mainly lack of money AFAICR.

    • Re:Beat Frequency (Score:3, Insightful)

      by mOdQuArK! ( 87332 )
      I don't think this is the same thing as the beat frequency, unless the MIT web page is providing misinformation. If I remember correctly, the beat frequency effect comes out of the linear combination of two other waves.

      The effect that they are describing is due to the interaction of the ultrasonics with the nonlinear behavior of the air (or whatever medium they're working on). (I'm assuming that the nonlinear behavior of air is one of those second or third-order effects which they don't bother telling people about in high-school physics.)
  • In this space, only you can hear everyone scream.

  • Interesting, but not for concerts (Score:5, Interesting)

    by hcdejong ( 561314 ) <hobbes@@@xmsnet...nl> on Sunday February 24, 2002 @08:49AM (#3060281)

    From the article: Pompei imagined that instead of loudspeakers blaring the same cacophony of instruments to all parts of the room, it would be more interesting to selectively spotlight the soloist to the left side of the audience, while featuring the percussion up front, and then switching them around.

    But when I go to a concert, I want to hear all the instruments - without having to move around the room.

    Also, I get the impression that current tests are being carried out in silent environments with few obstacles. In a concert, you'd have to crank up the volume of such a 'sound spotlight' in order to hear it over the 'general' sound system. And in a crowded hall, the sound from the beam would be reflected more. This would cause the sound generated by the spotlight to 'leak' out of the beam area, making it less effective.

    And (also important in a concert) the audio engineer can't hear what he's doing with the spotlights, making it very hard to get right.

    • And (also important in a concert) the audio engineer can't hear what he's doing with the spotlights, making it very hard to get right.

      I 'spect that the result could be *modelled* for the engineer's monitoring, so that might not be a problem.

      The question is whether this will actually be suitable for hi-fi music. Can the non-linearity of the air be exploited to provide a reasonably flat response? Such important details seem to be missing from descriptions of the system so far.
    • The article was not clear, but the way you would get the effect they are describing is not by pointing the sound *at* the different listeners. Instead, you point the spotlight at the point on the stage where you want the sound to come from and let the reflected sounds be heard by the audience.

      I used to work at the Media Lab and have seen the audio spotlight around. A few times at catered functions at the lab, the audio spotlight was used to mess with the caterers. By pointing the spotlight near their feet and playing a breaking glass sound, for example, they could be made to freak and look for what they'd dropped. I must confess only to hearing about this second hand so I can't personally vouch for how well it worked, but that is the principle that would be used for the concert scenario and from what I hear it worked well.

  • ..ah,. thats old hat. They demostrated a system like that a few years back on Tomorrows World (BBC, UK). But I expect you were all off drippling over Xena or Buffy......
    • I saw that one... It would be a great technology for use at rock concerts, nightclubs, etc. Zero noise pollution - if you're outside the target area it's completely silent.

      Hell, I'd like one for my living room... the neigbours would probably pay me to use it :-)
  • Does this mean I'll be able to listen to loud music in my cubicle now without bugging my coworkers?
  • A brittish company "1-limited" must be using something like this too, because they have created a home-theatre system that provides full surround sound, but only requires ONE speaker! You can reposition the "virtual speakers" around the room using a remote control. It currently does up to 6 channels, but they claim it can be extended to 8 (without hardware upgrade) if new surround sound formats are invented. Have a look at the .PDF that is on this page [1limited.com]. They don't give away many technical details unfortunately.

    • Different technology (Score:2, Interesting)

      by maaaaanis ( 180232 )
      The guys you're talking about are using a process which is all done within our hearing spectrum.
      The use slight delays to fool our ears into thinking that the sound is surrounding us. The pinnea (ear flaps) are used to channel and delay sound as it enters our ear to give us an impression of where the sound is coming from, so as sound hits our pinnea from one direction, it gets to the eardrum at a slighly different phase than from other directions, our brain learns to interpret these differences and give a direction to the source.
      The synthetic version of the process was called transaural. It was written up in the AES journals at least 7 years ago...
      • I'm pretty sure they go way beyond simple delay effects (like the tricks a Sound-Blaster Live can do when wearing headphones, to simulate sounds going behind you and above+below you).

        They say: "Unlike virtual surround systems, which employ psycho-acoustic techniques to simulate a surround sound effect, and require rigid listening conditions to be met the Digital Sound Project produces genuine surround sound within a wide listening area" They definately talk about sound-beams which reflect off walls to produce sound which appears to originate on the wall.

        Quotes on this page [1limited.com] make me think this is going to be something special
  • ... an N'Sync'ed beam ;)
  • Wow, the world of David Lynch's crappy Dune film are getting closer and closer.

    (((shudder)))

    InigoMontoya
    • Heh, that's the first thing I thought of when I saw this story too.

      But I actually liked Lynch's version of Dune... if I surgically remove the rain at the end from my memory. I saw the movie, and it was so bizarre it kind of blew my mind, so I just had to go out and find the book. The movie on the scifi channel, even though it was a lot more accurate, just didn't do anything for me.

  • I builda pain-field generator back in the late 80's and you have been able to build kits for years and years now (remember those amazing discoveries ad's that had levatioion and laser guns? well some of their stuff does work.) You have 2 types of sound field generators.. I am unsure of the targetted, mostly what I seen and dabbled in was wide area, you stand behind the speakers...way behind to keep from getting effected. was massive amounts of certian frequencies that product intense headaches and or the other end of the spectrum that causes un-controllable vomiting and bowel movements. no use of which is safe because of the insane amounts of sound generated... (making the inside of a jet engine sound nice and quiet)

  • They discuss various uses, from musical performances to possible weaponization.


    OK, I know those damn weirding modules weren't *really* part of the Dune story, but someone had the idea that they would make a great addition to the film, and these folks are obviously on the same track.


    **BUSH!** His name is a killing word!

  • I always wondered how in Star Trek they dealt with the privacy invasion of having your messages broadcasted within an entire room (they never wore headphones).. but this actually answers the question.

    Now when you see Riker listening to a message from the Captain, you can be safe in the knowledge that Worf isn't listening in.

    Really though, this technology is extremely cool. Anything that would have seemed like magic twenty years ago HAS to be cool. I mean, who wouldn't be freaked out by a system that can make one person in a room hear one thing, and another person hear another?
  • I tried doing this about 5 or 6 years ago could never get it to work though. I wonder what their rig is like. I think it was Kodac that was sponsering the research using their gold thinfilm ultrasound transducers. I was just a coop student and it seemed all kind of bogus to me. They never would explain to me the "non-linear effects" of air. Hard to know how to modulate the source to get the proper sound. Congrads guy on a tough dev job. You aced it. And hurry up if my wife and I get in one more fight about the radio station it might not be good.
  • ...it's our favorite song! And it's getting louder too! Oww...It's hurting.

  • dune? (Score:1)

    by j3110 ( 193209 )
    oh great... I was hoping they wouldn't make those silly weapons from Dune. Someone's going to sneeze into a microphone and it's not going to be pretty :)

    The upside: Maybe LAN parties won't sound like 20db of static with spurious explosions.

    How long until it's used in an assasination with no evidence to convict the culprit?
    • Heh, headphones have been mandatory at every LAN party I've been to... I don't see why you would do otherwise for gaming in general, really. Being able to tell where things are by sound is invaluable in FPSes.

      As to Dune... yeah, Lynch was a crackpot. ;-)

  • Targetted ads (Score:2, Insightful)

    by cat_jesus ( 525334 )
    I can see it now, because of security issues all sporting events require facial recognition technology. To offset the cost of implementing the technology the stadiums sell the data to advertisers and lease space for directional sound equipment so they can target ads to specific people in the stadium. Or they could decide to target ads to certain demographics. All white guys in their 40's will get ads for Michale Bolton's greatest hits. Bleh

    Cat
  • Perhaps not the intended use, but I think this might catch on as the next-generation, technological whoopee cushion.

    Coming to a Jr. High near you.

    -Joe
  • ... and you could have the perfect weapon for getting someone to shut up!

  • Lots of Applications (Score:5, Insightful)

    by InfoVore ( 98438 ) on Sunday February 24, 2002 @11:53AM (#3060614) Homepage
    There are many more applications of this technology than the article lists:

    Multi-lingual Movie Theaters:
    Push a button on your arm rest and get the movie in English, French, Spanish, etc. (or in the original Klingon). Pushing the "G-Rated" button on your child's seat would tune out all those nasty 4-letter words (although visual violence and sex would remain on screen). You could also control the volume from whisper to bone-rattling.

    Spot sound cancelation:
    Lots of uses for this one. Create quiet zones by coupling with sound cancelation techniques. Imagine being able to punch the "Cone of Silence" (CoS) button in your office when your co-workers are getting a little loud or you need to really concentrate. You could also listen to your favorite music without wearing headphones or disturbing your cube-mate. This would be particularly useful for airplanes. You could engage your CoS when you want to get some rest or simply to block out the airplane noise. The pilot could engage everyone's CoS to nudge people into staying in their seat (if they get up, they get the loud airplane noises again). Or how about for good neighbor relations- are your neighbors complaining that your dog Sparky is keeping them up all night with his barking? Just install the BarkStop(TM) system in your back yard and put the tracking collar on him. All his barking gets muffled. It also acts as an invisible sonic fence to keep him inside the yard.

    Super Surround-Sound Home Theater:
    DVD's could contain extra sound encoding information to paint the viewing space with individual sounds. All of the sounds in the movie would come from a 3D location in space. This is similar to what the conductor in the article wanted to do.

    Point-To-Point Smart Intercom:
    Rig an office building with locator ID badges, tracking microphones, and sound projectors. Now you can tap your badge ala ST:TNG and speak to anyone in the building in total privacy. Rig it into the phone system and you can talk to anyone out of the office via their cell phone or in another office building a continent away.

    Thrill rides and haunted houses:
    Structure the experience by controlling sound location, volume, etc. Easy to make "ghosts" follow behind you, chains rattling above, and so on. Heighten the experience by using selectively transmiting magic frequencies that induce unease and nervousness.

    And of course practical jokes:
    Echoing footsteps, sqeaky shoes, body sounds, etc. Use your imagination.

    The possibilites are almost unlimited. It is funny that what the DOD really wants out of this is a classic SFish Sonic Disruptor.

    What I really want out of it is a Sonic Screwdriver.

    I.V.

    • multi lingual theatres - the sideband supression is good, but just the same a three degree cone projected from a sufficient distance would be liable to cause interference between seats. bilingual movies is an interesting idea, but i would think that bilingual via headphones would be much easier to implement (and a lot cheaper for theatre owners than having 80+ beam units for each seat (with lower sound quality than people are used to)).

      spot sound cancellation - the time required for the propagation of the sound from a remote 'audio spotlight' would probably make canccellation impossible unless the signal was highly correlated and could be accurately predicted. an interesting idea, though, if it could be implemented...

      i really like the other ideas. that haunted house one - i wonder if that's like the sega joypolis implementation?
      • Some of the information I read about this a couple of years ago indicated that the ultrasonic beams they can use (obviously more expensive) can create very tight sound points in space (sound voxels, soxels?). I wish I could remember the reference, but they indicated that they could easily focus seperate sounds on individual ears, such that someone a foot away could hear little or none of the sound. With tight enough beam widths, perhaps the sidelobe interference could be minimized (similar to the way it is done in phased array radars). A worst case for a multilingual theater then would be to put the seats a little farther apart or to have language specific rows or sections of the theater. The technology would be expensive, at least at first. The likely first applications would be in Imax or similar specialty theaters in big urban areas.

        Spot sound cancelation hardware would have to be installed near the effect area to counter the problems you described. Probably the user would have to wear a locator badge with wireless microphones. In general, sound cancelation technology acts more to muffle and reduce the volume of sounds than to actually eliminate them. Still useful and implementatble for the applications I described, I think.

        Thanks for the compliment on my other ideas. They are what occured to me when I first heard about this stuff a couple of years ago.

        The Sega Joyopolis thing probably is an implementation of the haunted house idea. BTW, the magic frequency idea isn't totally new. Decades ago, some haunted houses used a subsonic pipe organ whistle to generate those "creepy" frequencies. I imagine today it would be simple to do with specialized subwoofers and a frequency generator. Being able to spotlight people with these things would be interesting though.

        I am very interested in seeing how this technology develops in the next couple of decades.

        I.V.
  • Issue a portable ultrasound generator that runs off a battery and spits out random noise. Should be enought to turn any directed ultrasound beams into garbage. Or maybe you could combine this generator with noise cancellation technology and make the voices go away... Sounds a lot more expensive though.


    Who knows if this would actually work, but it might be fun at a concert...

  • So now, not only can your grumpy neighbour throw stuff at your dog in the backyard, he can torment it with aimable ultrasonic waves.

    And if you thought idiots with laser pointers were annoying, just wait until they get ahold of the "pocket sound projector."
  • Lifeguards in public pools could use this technology to yell only at specific idiots, rather than annoying everyone in the pool with their whistles and bullhorns.

  • Whisperers arch (Score:1, Interesting)

    by Anonymous Coward
    Has anyone seen one of those at a museum? You stand beneath a parabolic arch and there are 2 focal points. If someone is standing in each of the focal points they can whisper to each other without anyone else being able to hear.

    Also, if you go to the ruins of Chichenitza in Yucatan Mexico, you can stand in front of the pyramid and clap your hands and it comes back with a ricochet sound, but people beyond a certain angle can't hear anything but a clap..
  • Reasons not to peruse /. first thing in the morning:

    I read the headline as "Targeted Sound Beans" and wondered WTF they were doing with Java now??

    Remember, good boys don't put beans in their ears!

    [Where did I leave my injectable caffeine??]

  • This is going to be most useful for situations where you have multiple, different audio sources in the same area and don't want them to interfere. Museums and trade shows come to mind. The volume application is probably going to be point-of-sale displays.

  • Re: (Score:1, Funny)

    by account_deleted ( 4530225 )
    Comment removed based on user account deletion
  • If Targeted Sound Beams are almost here, can Targeted Advertising Sound Beams be far behind?

    Just imagine, you're walking down the street. You hear an advertisement for the strip club half a block down. You try to run away, but the sound seems to follow you. When that ad ends, you then hear the beginning of a new advertisement how to make money fast! You try crossing the street, but the sound just seems to follow you.
  • Imagine the PRANKS you could pull with something like this. Nothing like talking to someone in their sleep from 100 meters away while the person sleeping next to them has no clue.

    Keep someone thinking the phone is ringing, but everytime they answer it, only a dialtone.

    And ringing the doorbell and running just got a lot less risky. :)

    Want to start a fight between two people? EASY! :)

    -Restil
  • I played with this at Bose a few years ago, and it's very disorienting at first. Pompei may have taken this further than the prototype I saw, but the version I played with essentially created audible sound coming from the point where the ultrasound beam reflected off of a surface.

    It's very odd to play with one of these things. We put on a CD and started waving the ultrasound array (housed in a flashlight body) around the room. I felt disoriented pretty quickly as my brain tried to figure out where the sound it coming from.

    One of the more interesting effects, as mentioned in the article, is pointing the array at someone's head and turning the volume down. Only the target can hear, because it's essentially like having a headphone on. The sound it's generating is simply too quiet to hear unless you're less than a few centimeters from the source.

    My favorite application for this is car navigation systems. I like the idea of a GPS navigation system that can give spoken directions to the driver without bothering all of the passengers in the car.

    Just imagine- some day these things could be as common and annoying as laser pointers. Imagine walking down the street with some teenager 200m away whispering in your ear. It's going to be ugly.
  • IIRC, Someone constructed a device that looked like a pair of binoculars, but had a pair of tightly focused ultrasound transducers at the front.

    The device was set to emit a very narrow beam at a frequency and power that would be inaudible to people, but extremely painfull to horses.

    Someone used this to try to knock a horse out of a race, and clean up on the betting.

    This was several years ago I believe.

    Escoutaire

  • We already have sound weapons. (Score:3, Funny)

    by Bowie J. Poag ( 16898 ) on Sunday February 24, 2002 @03:28PM (#3061435) Homepage


    Theyre called "Low riders".

    Theyre used mainly by inner-city minorities and retarded white kids who find the cul-de-sac an inappropriate place to express their blackness.

    Ever get the feeling that all that bass is being used to compensate for not being held enough as children?

    Cheers,
  • I wonder if the same technology - using interference patterns - could be applied to put a 3000W subwoofer in the palm of your hand -- or in the armrest of you pickup truck. ;)
  • Good to see progress in the commercial sector...
    but I believe this was discovered and prototyped at the MIT media lab at least 2 years go.....
    I believe /. did an article about it....

    Something to do with invisible speakers ;)

    (exact same thing.. nonlinear response of sound in air, ultrasound breaknig down, etc)
  • besides the standard applications most can think of for this technology, i'm guessing it will be used heavily by those in academic electronic/art music circles, as well as mixed media artists.

    currently, going to an academic tape music concert involves sitting in a room listening to sixteen channel pieces on sixteen channel sound systems (prett cool in itself). i can only imagine some of the stuff composers will come up with when they have 16 targeted audio beams at their disposal.

  • Those of you sitting in rows 1-10 will be hearing the english sound track. Rows 11-20 will hear the french sound track. Those in rows 21-60 have cheap movie tickets that do not cover the RIAA music royalties and will hear the voice only sound track. Please enjoy the film.
  • This was discussed two years ago on the StageCraft mailinglist, including possible uses and ramifications for the theatre.
    StageCraft Thread [theprices.net]
  • I knew of this years ago. I tried to tell the nice people in white about it but they didn't listen. Wait...the voices...they're calling me again...

  • Conspiracy theory alert... (Score:3, Interesting)

    by cr0sh ( 43134 ) on Sunday February 24, 2002 @08:23PM (#3062761) Homepage
    Want to learn something interesting? Look up "voice to skull" technology. I have managed to find direct evidence (via government websites) of both the United States and Austrailia researching this technology. Patents exist, and can be looked up. The technology is real, as has been known about for a few decades.

    It looks like the tin-foil hat kooks may be right.

    Two systems exist:

    1. Audio over ultrasonic carrier - essentially uses the skull to filter the ultrasonic carrier wave - at that point it is simple bone conduction.
    2. Audio over microwave carrier - this one is more "advanced" - it uses frequencies in the microwave region as the carrier wave for the sound. These waves then stimulate the vestibular region of the brain, which filter out the carrier and leave the sound information behind for the brain directly to figure out - causes strangeness to the recipient - a "voice in the head" type sensation. This form of V2S was first noticed by microwave and radar engineers who would "sense" or "hear" (in their heads) "clicks", "pops" and "whine" type noises as the worked around unsheilded microwave equipment.

    Both of these technologies are real, as far as I can figure. Neither is "high quality" - but voice quality only (in fact, the microwave V2S system is actually pretty poor quality - rendering the voices in a "growling" type tone - which could be interpreted as "demons talking"). Both have potential "sinister" applications - neither have the quality of use for anything else.

    I wish I was making this up - I haven't found anything that says "impossible" yet - but if someone could look into this with me, and let me know that I am wrong, I would love to see the information...

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