back to article BAD VIBES: High-speed video camera records your voice from trash

Run a camera fast enough and its images can capture sound from the way nearby objects vibrate, according to boffins from MIT, Adobe and Microsoft. The experiments, announced by MIT, worked so well that they claimed to have recovered sound from the leaves of plants, and the vibration of a crisp packet. The latter, as the …

  1. Anonymous Coward
    Anonymous Coward

    Er....

    Wasn't there a rumour that one of the spy agencies had bugged the other by bouncing a laser off a mirror through a window ?

    1. Charles 9 Silver badge

      Re: Er....

      True or not, it's not unheard of, and I'm pretty sure I've heard of a laser being used to detect vibration at some point in the not-too-distant past. If they did, they didn't use a mirror but the glass itself, much like how a shotgun microphone focuses on the acoustic vibrations of the flat window panes.

      But here I thought they were trying to recreate the real sounds off old silent cinema (no chance at only 24fps). Silly me...

      1. Lusty

        Re: Er....

        The real question is, now that this is public what did the spy agencies just invent that's so much better?

        1. VinceH Silver badge

          Re: Er....

          "The real question is, now that this is public what did the spy agencies just invent that's so much better?"

          The sooper dooper pooper scooper. That's the nickname given to a device in an old Piers Anthony novel, IIRC, which can be focused on any point in space and time, allowing the viewer to see what happened at that point. Things like walls, distance, etc are completely irrelevant.

          Aha - a quick search reveals it's called Macroscope.

          1. Caesarius
            Pint

            Re: Macroscope

            There's an Asimov story that pre-dates the Macroscope by 13 years: The Dead Past, Asimov, where being able to see and hear anything in the past, including only 1 second ago, has devastating implications for everyone's privacy.

            (Not that I'm casting aspersions on The Macroscope: I'd not heard of it, and now I want to read it.)

        2. Bartholomew

          Re: Er....

          The real question is, now that this is public what did the spy agencies just invent that's so much better?

          You mean like some kind of exotic Acoustic Vector Sensor that can record all conversations whispered or shouted within a 25 meters radius ?

          http://www.newscientist.com/article/mg21929364.400-matchsticksized-sensor-can-record-your-private-chats.html

      2. Anonymous Coward
        Anonymous Coward

        Re: Er....

        But here I thought they were trying to recreate the real sounds off old silent cinema (no chance at only 24fps). Silly me...

        Especially since the older ones were 18fps not 24fps.

      3. Tom 13

        Re: real sounds off old silent cinema

        There's a reason so many of the stars of the silent movies failed to make the transition to the talkies: their squeaky voices were unpalatable to audiences. And as someone who has a voice made for newspapers, I understand this.

    2. Andrew Torrance

      Re: Er....

      Yep , but that requires you to fire a laser at a target such as a window and look at the light coming back . In theory this method has the POTENTIAL , to be able to detect the sound from anything that can be viewed optically without giving away your position by firing a nice big juicy laser which can easily be detected .

      1. Charles Manning

        No ned to fire a laser

        "Yep , but that requires you to fire a laser at a target such as a window and look at the light coming back "

        Nope. You could equally use a passive reflection too.

        The benefit of a laser, or any other bright reflection, is that the modulation is much higher and thus easier to detect. It does not need nearly as much signal processing as the crisp packet mechanism.

        The laser also allows you to modulate with a carrier and thus remove unwanted signals.

      2. Ralara

        Re: Er....

        X-Ray laser?

        infra-red?

        doesn't need to be a big red spot.

    3. The last doughnut
      Boffin

      Re: Er....

      Using a laser and opto-electronic detector to pick up vibrations from a reflective surface and convert the resulting signal into something you could listen to is pretty basic and could easily be done with no need for any fancy processing. Just some analog electronics.

      This is a lot of very complex image processing and I for one am glad that the article did not try to reproduce any of the formulae involved!

      1. Caesarius
        Boffin

        @The last doughnut Re: Er....

        I thought that the laser technique required a splitter, sending one ray via the moving surface (window), and then combining them, and looking at the intensity of the combined rays. The phase modulation is thus recovered, but you clearly need some very stable fixings for the laser, the splitter, the combiner, etc. And anyway, every time a lorry goes by everything will move and the wanted signal will be drowned out.

        That's one seriously difficult technique.

        1. Charles 9 Silver badge

          Re: @The last doughnut Er....

          Doesn't sound much more difficult than trying to use a shotgun mic, and it has the same issues since both rely on the vibrating window glass. The laser offers greater range, though.

        2. TechnicalBen Silver badge

          Re: @The last doughnut Er....

          Or you could just look at the movement of the laser on the surface (providing high enough resolution/lenses).

          It's a small movement, but it would have one none the less. http://lifehacker.com/5961503/build-a-laser-microphone-to-eavesdrop-on-conversations-across-the-street

          Though using something outside the (normal) visible spectrum is even better.

    4. Bloakey1

      Re: Er....

      As Charles says, it was based on the vibration of the window and translating the distance variation caused by vibration. Sometimes you could focus on an item in the room that vibrated, glass lampshades work very well.

      There was an interesting bug found in the US embassy in Moscow and to this day nobody knows hw it works!!!

      1. hplasm Silver badge
        Boffin

        Re: Er....

        "There was an interesting bug found in the US embassy in Moscow and to this day nobody knows hw it works!!!"

        Would that be the one with the tuned microwave cavity with a diaphragm that was vibrated by sound?

        I think they did figure it out fairly quickly- after it was discovered, which took years...

        1. Charles Manning

          Cavity resonator urban myth

          Yup, the bug that nobody understood is just a good old urban ledgend.

          Maybe the embassy staff would not have known how this works, but anyone that has worked with microwave would.

          As Wonkapedia says in http://en.wikipedia.org/wiki/Thing_%28listening_device%29 , the principles of a cavity resonator was well understood and the concept of a modulating a cavity resonator like this was even patented in the US in 1941 - 4 years before the bug was installed.

        2. Pet Peeve

          Re: Er....

          The infamous wooden eagle bug was "gifted" to the US in 1946 (supposedly carved by schoolchildren), and hung in the US Embassy, in the Ambassador's office, over his desk until 1952, when a bug sweep found it.

          The US didn't officially tell the USSR they were onto it for almost a decade after that - I don't know if they had staged conversations in front of it during that time, or if they just stuck it in a basement until they made a stink about it in the UN.

      2. John Smith 19 Gold badge
        Boffin

        @Bloakery1

        "There was an interesting bug found in the US embassy in Moscow and to this day nobody knows hw it works!!!"

        1/2 true.

        The device was found in a carved wooden copy of the American seal given as a "gift" by the Russians.

        The device was a metal structure with a thin metal membrane on one end.

        When "illuminated" by a microwave beam (IIRC) the device's resonant frequency shifted which could be detected. Having no battery it never ran out and only emitted RF when painted by an external source.

        It's basically the principle of an RFID tag.

        1. Sir Runcible Spoon Silver badge

          Re: @Bloakery1

          +1 for the Macroscope reference, I loved that book - lots of nifty ideas, especially the 'traveller'.

          If you like Piers Anthony I highly recommend his incarnation series.

      3. Jess--

        Re: Er....

        would you be referring to the eagle statue as the "Interesting Bug"?

        that worked through RF resonance and harmonics which shifted very slightly with vibration (like sound)

        all that was needed was a transmitter (on the right frequency) and a very sensitive receiver close by.

        Still took them years to work out how it worked

    5. John Smith 19 Gold badge
      Unhappy

      Re: Er....

      "Wasn't there a rumour that one of the spy agencies had bugged the other by bouncing a laser off a mirror through a window ?"

      It's called a laser Doppler velocimeter. It's been claimed to have been in use since the 1970's.

      Wheather or not it's actually worked is another matter....

    6. This post has been deleted by its author

    7. Alan Brown Silver badge

      Re: Er....

      "Wasn't there a rumour that one of the spy agencies had bugged the other by bouncing a laser off a mirror through a window ?"

      It's easy enough to do/demonstrate and is an extreme use case of the photophone - the window itself is the mirror, not something inside the room (dirty windows reflect more light).

      The lesson to take away from the laser trick and the high speed camera trick is "double glazing + heavy multilayer curtains, if you must have windows at all"

  2. HMB

    Rolling Shutter FTW

    Using the rolling shutter from a regular DSLR at 60fps was both inspired and amazing, very impressive result.

  3. DJO Silver badge

    Insufficient data

    The signal processing of the video wasn't in anything like real time: “Processing each video typically took 2 to 3 hours using MATLAB on a machine with two 3.46 GHz processors and 32 GB of RAM”

    Without knowing the length of the videos in question that is a useless statistic. If each video was 1 to 2 hours long then that's quite good, if they were around 10 to 15 seconds then there's a lot of work to be done.

    Good to see a nicely ambiguous heading from El Reg, there's no way this could ever reconstruct the audio from old silent movies but of course that claim is never made or explicitly implied, the oblique suggestion is plausibly deniable - well done chaps!

    1. User McUser

      Re: Insufficient data

      Given that the audio sample they were trying to see was "Mary Had a Little Lamb", it would seem to be more the latter length. So not particularly swift.

      Still, it's just a matter of a few more iterations of Moore's law and/or better optimization before it becomes reasonably quick.

    2. Caesarius
      WTF?

      Re: Insufficient data

      MATLAB?! I've heard MATLAB referred to as "FORTRAN meets APL in car crash", but my point is that it is useful (very very useful) to prove an algorithm but not as quick as "proper code". (Oh, and it does very pretty graphics for little effort.)

      So I wonder what 2 hours would come down to.

      1. Steve Todd

        Re: Insufficient data

        It's more likely something you'd implement in an ASIC or FPGA, at which point it's probably going to be at or near real time.

        1. Anonymous Coward
          Anonymous Coward

          Re: Insufficient data

          Cheaper to just 1) Write your code in a real language, 2) Chunk your data up into manageable sections and 3) Throw Hadoop at the problem. ASICs are expensive. FPGAs aren't cheap either. Cloudy distributed computing resources on the other hand? Cheap as chips.

          Ironic.

      2. Anonymous Coward
        Anonymous Coward

        Re: Insufficient data

        As someone posting from a machine with MATLAB on it, the speed of MATLAB varies greatly based on how you're using it. If they're using a lot of MEX code then the speed is semi-realistic. If not, optimised CUDA code would probably bring the processing time down to a minute or two.

      3. John Smith 19 Gold badge
        Unhappy

        Re: Insufficient data

        "MATLAB?! I've heard MATLAB referred to as "FORTRAN meets APL in car crash", but my point is that it is useful (very very useful) to prove an algorithm but not as quick as "proper code". (Oh, and it does very pretty graphics for little effort.)

        So I wonder what 2 hours would come down to."

        I think that question came up that Register article about doing software for economics.

        IIRC Mathlab Vs C++ came out about 500:1.

        so probably custom hardware needed.

      4. Anonymous Coward
        Anonymous Coward

        Re: Insufficient data

        2 to 3 hours using MATLAB..... probably 2 to 3 minutes if a real software engineer implemented it in a real programming language then!

      5. Alan Brown Silver badge

        Re: Insufficient data

        > MATLAB?! I've heard MATLAB referred to as "FORTRAN meets APL in car crash",

        Yup, but it's not as bad as IDL

        > it is useful (very very useful) to prove an algorithm but not as quick as "proper code"

        That doesn't stop people using it (or IDL) for production purposes

        (IDL is a display language FFS. Asking it to perform complex numerical analysis is madness)

  4. oiseau Silver badge

    Scared sh*tless

    I saw a rather dated sci-fi/spy thriller on cable a few days ago.

    Title was 'Eagle Eye', starring Shia LaBeouf and Michelle Monaghan (hot).

    Eagle Eye was a super computer with a conscience and among other even more amazing things, did what these university boffins are doing.

    Now, that was in a 2008 film ...

    I can't imagine what they can do 'now'.

    In any case, that this can be done almost scares me sh*tless.

    It seems that there's nowhere to hide, man.

    1. frank ly

      Re: Scared sh*tless

      Just sweep the room for potted plants and crisp packets before you have any sensitive discussions.

    2. Anonymous Coward
      Anonymous Coward

      Re: Scared sh*tless

      "Now, that was in a 2008 film ..."

      In the 1968 film "2001" two astronauts shut themselves in a space pod to discuss switching off the AI on the almost sentient spaceship's computer HAL - without it hearing them. Their faces are visible in profile through the pod's window - and HAL reads their lips. Murderous twists and turns then ensue - on both sides.

      D-a-a-i-i-i-s-s-s-s-y-y-y-y-y-y-y-y-y-y-y

      1. Sir Runcible Spoon Silver badge

        Re: Scared sh*tless

        I think that people were supposed to root for the humans against the machine in the the film Eagle Eye, yet when you look at it the machine was actually trying to defend people from being subjugated by powerful people who were violating the constitution left right and centre.

        Ironic.

  5. DaLo

    "Next step: CCTV cams that can eavesdrop on you"

    Not much of a step seeing as CCTV cameras often have built in microphones?

  6. Anonymous Coward
    Anonymous Coward

    Don't look at me in that tone of voice!

    1. Sir Runcible Spoon Silver badge
      Coat

      You sound a funny colour today.

  7. psychonaut

    i can tell when you are lying....

    your lips move. incidentally, so does that packet of cheesy whatsits.

    (or cheesy poofs for our cousins over the pond).

  8. Phil O'Sophical Silver badge
    Headmaster

    Mary had a little lamb?

    Wasn't that Edison's test, not AG Bell's? Bell's famous line was "Come here Mr. Watson, I need you"

    1. Someone Else Silver badge

      Re: Mary had a little lamb?

      Yeah, leave it to AT&T to try and cop GE's thunder.

      1. Sir Runcible Spoon Silver badge
        Coat

        Re: Mary had a little lamb?

        Ah, good old-fashioned nursery rhymes from my childhood - lovely.

        Mary had a little lamb, she couldn't stop it gruntin'.

        She took it up the garden path and kicked it's little **** in.

        Mary had a bicycle and she rode it on the grass*,

        Every time the wheel went round a spoke when up her arse.

        Now when Mary rides her bike, she rides it back to front.

        'Coz <you can work this line out for yourself>

        *grass as in 'parse', not as in 'mass'

  9. Mage Silver badge

    Laser eavesdropping

    yes, it's off the shelf to eavesdrop by a special IR laser on a window and process the reflection. That's quite simple.

    This is more complex and defeats special anti-eavesdropping windows.

    1. Pascal

      Re: Laser eavesdropping

      I was gonna say "closing the blinds" defeat this easily, but I guess the damn things will vibrate too.

      1. Charles 9 Silver badge

        Re: Laser eavesdropping

        That and the windows can also vibrate from the walls which can't be muffled easily.

    2. ian 22
      Happy

      Re: Laser eavesdropping

      I think we should use the cone of silence.

      Get smart, man.

      1. veti Silver badge
        Boffin

        Re: Laser eavesdropping

        The countermeasure to eavesdropping from vibrating windows is to pipe music through the window frames. This process defeats that countermeasure, if (and only if) you can observe the object normally (i.e. at *exactly* 90 degrees to the glass) through the glass, so that distortion caused by refraction isn't an issue.

        My next suggestion would be to combine the musical window frames with double-glazing where the two panes are not quite parallel to one another, so it's literally impossible to see through from any angle without some refractive distortion.

        Where do I collect my fee?

        1. Sir Runcible Spoon Silver badge

          Re: Laser eavesdropping

          The cone of silence is the schnizz.

        2. Alan Brown Silver badge

          Re: Laser eavesdropping

          "My next suggestion would be to combine the musical window frames with double-glazing where the two panes are not quite parallel to one another, "

          Properly done acoustically controlled double glazing should always be done this way.

  10. Zog_but_not_the_first Silver badge
    Boffin

    The Stone Tape

    If you're old enough.

  11. Jason Bloomberg Silver badge
    Boffin

    Boom Boom BOOM BOOM

    Isn't this why anyone having a secret conversation whacks the Hi-Fi up to 11?

    Ironically apt icon -->

  12. TheProf
    Happy

    Nice

    Nice to see something on here that isn't asking for crowdfunding.

  13. Mystic Megabyte Silver badge
    Facepalm

    High speed insanity

    If you were to eavesdrop in my local using the favourite snack (pork scratchings) you'd go mad.

  14. AndrueC Silver badge
    Joke

    Mary had a little lamb, it used to jump so high.

    One day it jumped into a butcher's shop and now it's in a pie.

    1. soldinio
      Joke

      Mary had a little lamb, it backed into a pylon,

      A thousand volts shot up it's arse and turned it's wool to nylon

    2. Caesarius
      Paris Hilton

      Mary had a little lamb ...

      ... the doctors were surprised

    3. Ben Bonsall

      Mary had a little lamb,

      Now she's doing five years for bestiality.

  15. Anonymous Coward
    Anonymous Coward

    Mary had a little lamb,

    Little lamb little lamb,

    Mary had a little lamb,

    whose fleece was white as snow.

    —Assassins’ Redoubt,

    Final Transmission

  16. willi0000000

    this is going to make the mob more healthy . . . no more bags of snack food at meetings where they discuss "business."

    [can you use this on a cannoli?]

  17. Callam McMillan

    CCTV that can eavesdrop?!

    I had to laugh at the idea that a CCTV camera will ever be able to eavesdrop on you. Yes it may be technically possible, but if you look at all the CCTV footage available on the internet, even if the person was holding up a placard with what they're saying printed like in the cartoons, it'd still be an unreadable blurry mess.

  18. chivo243 Silver badge

    Calling Harry Caul

    I think if anyone really wants to hear what you're saying, they will find a way...

    http://en.wikipedia.org/wiki/The_Conversation

  19. NorthernCoder
    Coat

    Tinfoil hats...

    Would this make the tinfoil hat brigade reconsider their choice of head wear?

    1. Anonymous Coward
      Anonymous Coward

      Re: Tinfoil hats...

      What, we'll start seeing the medieval helmet brigade next?

    2. DropBear Silver badge
      Trollface

      Re: Tinfoil hats...

      Probably not, but it'll be quite hilarious once the spooks start listening in by recording the vibrations of the piece of black tape stuck on the webcam to prevent them spooking in the first place...

  20. logistix

    Can someone say TEMPEST! VAN ECK PHREAKING! Let alone the old school laser beam eavesdropping trick, pfffft. The pretty blue and green blinking lights on your routers, switches and computer monitors emitting electromagnetic frequencies tell us some interesting things too.

    1. Lusty

      "The pretty blue and green blinking lights on your routers, switches and computer monitors emitting electromagnetic frequencies tell us some interesting things too."

      No need for LEDs, the monitor cable gives off sufficient EM to read the screen remotely if you're clever about it. El Reg reported this years ago.

  21. sjsmoto

    If walls could talk...

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