back to article I can hear the light! Boffins beam audio into ears with freakin' lasers

MIT boffins have used low-power lasers to beam audio directly into a subject's ear. The technique relies on the interaction between light and water in the air, a phenomenon known naturally enough as the "optoacoustic effect". In their experiments, the researchers found they could use this to transmit an audio signal which, …

  1. Anonymous Coward


    That's where the strange voices are coming from that I keep hearing in my head !

    1. TeeCee Gold badge

      Re: So...

      No, that's from the miniature radios that the Illuminati implanted in your teeth.

  2. Anonymous Coward
    Anonymous Coward

    I assume...

    You could eavesdrop on the energy/radio emissions of the laser instead? XD

    1. phuzz Silver badge

      Re: I assume...

      My first thought that if they're scanning the laser with a moving mirror, that you'd probably be able to hear a faint sound from the mirror itself.

  3. Blockchain commentard

    Surely if you can make a noise with lasers, just reverse it and you can pick up the audio from the vibrating air/water molecules? Simple science at it's best !!!

    1. teknopaul

      I've heard it said you can do that with laser on glass to listen to what is going on in a room across the block.

      Trouble with doing that with water molecules is you need ones that apart from the sound are otherwise stable.

      1. DCFusor
        Black Helicopters

        You can, but

        The glass has terrible frequency response - the mass makes it a good low pass filter.

        The room reverb is horrible - even with a good microphone at many feet from the talker in those big rooms adversaries leaders and diplomats favor with lots of reflective surfaces that don't absorb echos.

        Other vibrations - passing cars, HVAC, elevators and what not....shake the glass really well.

        Back in the day I helped write some code to deconvolve that kinda stuff....success was pretty iffy.

      2. M.V. Lipvig Silver badge

        I imagine that if they are announcing that it's possible, it's because they got it to work. Pretty neat stuff.

        All you need to prevent laser eavesdropping is a vibrating sex toy taped to the glass Stops the eavesdropper while sending them a message about what they can go do to themselves.

    2. Chris G

      @ Blockchain commentard.

      A couple or three decades back I heard of an intelligence agency that was experimenting

      with non visible lasers to read the CO2 from breath in the hope they could fire their lip readers.

  4. Jason Bloomberg Silver badge


    Why am I reminded of the film "Scanners" and left wondering how many rats were scraped into bins while they determined an appropriate laser wavelength to use?

  5. Will Godfrey Silver badge


    I feel sorry for all those poor people sent off to the loony bin when they really were hearing voices while nobody was there.

  6. Primus Secundus Tertius

    Surely some mistake

    16MHz as an electromagnetic wave would have a wavelength of about 19 metres, not 1.9 microns.

    1. ThatOne Silver badge

      Re: Surely some mistake

      Definitely: 16 MHz would be the decameter shortwave radio band. Some laser.

      Fortunately the real article's abstract helps: It mentions they used a "1.9 μm thulium laser".

      1. M. Poolman

        Re: Surely some mistake

        Many zeroes dropped, I make it ~160THz

  7. Suricou Raven


    I think someone lost a few zeros.

  8. dbayly

    Ain't science wonderful ?

    Oh, finally - advertisements beamed to your ears only! And other delightful applications.

    1. Jess--

      Re: Ain't science wonderful ?

      That was my first thought too.

      walking past shops could become very annoying.

      driving towards an unscrupulous garage could result in unusual noises seeming to come from your car

      1. Chris 69


        I wish I'd thought of that. Seriously cynical old git that I am.

    2. VikiAi

      Re: Ain't science wonderful ?

      You just have to buy my special dark glasses for your ears!

    3. John Brown (no body) Silver badge

      Re: Ain't science wonderful ?

      Yeah, The Space Merchants was supposed to be a warning of a dystopian future, not an instruction manual.

  9. Flak


    Not the water in the air, just don't move if you want to hear.

    It will be interesting to see if there will be a real world use case at some point, or whether this will stay in the lab.

    Love reading articles like this - technology applied in really creative ways - just because you can!

    1. mosw

      Re: Freeze!

      Why would you have to stay still? I would think that having ceiling mount lasers tracking your movement would be well within the capability of current technology.

      In some dystopian future I could see Google/Amazon installing such a system in your local mall so it can whisper personalized purchase suggestion in your ears as you walk around.

  10. Andytug

    Oh great, laser headphones...

    Think of how many ignorant audiophiles they'll be able to fleece with those...until they find out they only work if you sit in exactly the right chair and keep your head perfectly still.....

    1. Evil Auditor Silver badge

      Re: Oh great, laser headphones...

      you sit in exactly the right chair and keep your head perfectly still

      I thought exactly that was the gist of being ignorant audiophile. Besides The Cables, of course.

      1. Korev Silver badge

        Re: Oh great, laser headphones...

        Audiophiles? What's in a Naim?

    2. Anonymous Coward
      Anonymous Coward

      Re: Oh great, laser headphones...

      "Think of how many ignorant audiophiles they'll be able to fleece with those..."

      Obviously you can't hydrate the air in your acoustic onanism room with plain old ordinary water - you need to buy very special oxygen free water containing homeopathic concentrations of pure gold, otherwise the spectral laser frequency's dynamic response will be adversely affected by the laser's inverse reverberant resonance simulacrum.

      Everyone knows that...

    3. Zimmer

      Re: Oh great, laser headphones...

      "Think of how many ignorant audiophiles they'll be able to fleece with those...until they find out they only work if you sit in exactly the right chair and keep your head perfectly still....."

      You're in my spot.....'s the T-shirt with 73 on it..

  11. Alistair

    All the chuckles aside, I'm wondering about the real world uses like most here ?hear? ....

    I know a couple of folks who *really* cannot wear headphones or earbuds. (autism can have some wonderful quirks) but would love to have music whilst working (I share this trait of being able to focus better while having music playing .... it helps with my ADD), and generally cannot have this as it becomes an environment conflict. (i.e they are allowed to have headphones or earbuds, cannot wear them due to physical reaction or as in my SO's case earbuds just *do not* stay in place due to the shape of her ears)

    I actually wonder if the arrangement could be made light enough and non-constrictive enough to solve their issues.

    But then I am a bit weird.

    I suppose the other application would be to communicate verbally with the herd of laser equipped sharks.

    1. TRT Silver badge

      I can haz music in the en-suite shower without cranking up the volume to the point where it wakes the sleeping beauty! Beam the laser down the water pipe using it as a kind of waveguide. Just don't start singing or you'll nullify the whole point of it.

    2. TRT Silver badge
    3. Swarthy

      For the folks that cannot wear headphones or earbuds; they may be interested in transducer (bone conductivity) headphones. They don't sit in/on the ears, but rather just in-front/behind them, so may not invoke the same sensory reaction.

  12. Toltec

    This is the voice of the Mysterons.

  13. 0laf Silver badge


    the govenment is beaming words into my head!

    1. Evil Auditor Silver badge

      Re: Nooo

      What a time for being paranoid!

      A while ago I considered giving it up. But now, most certainly not!

  14. MiguelC Silver badge

    "optoacoustic effect"

    They lost that once-in-a-lifetime opportunity of using the confusing - although correct - term "optootic effect"

    It'd make those boffins read twice, wouldn't it?

  15. ratfox

    Hearing light? That's nothing

    This guy can see noises

    1. Tridac

      Re: Hearing light? That's nothing

      That was in the 60's, but different source...

  16. DubyaG


    Perhaps this is how sharks communicate? They have lasers, right?

    1. eldakka

      Re: Sharks!

      Does this mean a school of sharks with frickin laser beams on their heads has been re-designated as an orchestra?

  17. Anonymous Coward
    Anonymous Coward


    Oh, great, just one more way to replaced LSD. "Oh, man, did you hear those colors?"

  18. LateAgain

    Gotta ask

    Does it melt the earwax ?

    1. David Roberts

      Melt the earwax?

      Not if you use mirror finish ear plugs.

      La la la........

  19. Fred Flintstone Gold badge

    I know some folks ..

    .. where the beam would just leave via the other ear.

    That said, I would never trust them near anything with a laser to start with. I even worry that they will at some point discover their mice are optical.

  20. anthonyhegedus Silver badge

    There’ll only be two use cases for this:

    1. Listen to soothing music through your skin whilst being tatooed by a giant laser or having your earwax hygienically vapourised.

    2. Adverts. These ads will also know if you’ve been listening by detecting subtle changes in body temperature and pulse. If you haven’t been listening, the advert is repeated incessantly until you have. Or until you agree to buy whatever it is that’s being advertised monthly.

    1. Dimmer Silver badge

      Weather control?

      Or how about a tractor beam, have you seen the audio box where the modulated sound waves coming from speaker on the walls are used to move objects in 3 dimensions?

      How about a sound based defense shield?

    2. M.V. Lipvig Silver badge

      Oh no, not #2! That would result in people being driven to burn down ad agencies and factories to put their tormentor out of business!

  21. Anonymous Coward
    Anonymous Coward


    Could this be used to keep the music loud on the dancefloor, but quiet enough to speak over in the rest of the club?

    1. Swarthy

      Re: Dancefloors?

      I think decent baffles and audio engineering might be cheaper. Some decent electrostatic speakers would have a similar effect, but they might not be cheaper.

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