DIY Flanagan Neurophone lets you hear with ultrasound

[Andreas] wrote in to let us know about this DIY Neurophone project. Apparently a Flanagan Neurophone uses ultrasound in some manner to transmit audio directly to the body, or nervous system? Needless to say we are a bit skeptical of anyone whose wiki page leads directly to pyramid power. In fact most of the references to this thing start rambling about some pretty pseudo-scientific theories.

At any rate, the schematic is clear and simple enough for anyone who has the parts to easily try.  The only challenge might be tuning the thing with a signal generator or audio feed. So how about it, any one have a TL494 pulse-width modulation controller and want to be a guinea pig?

Comments

  1. akismet-a8c1e1fc23835324d400ef9acfc5d14b says:

    No need to be skeptic, since there is no magic here. It already exists and is sold : http://www.holosonics.com/technology.html
    I tried another brand (I don’t remember the name) and the results are very impressive : highly directive sound that can only be heard when the speaker points at you.

    It is even used on military vessels as pirates repellent (since the USS Cole bombing AFAIK)
    http://en.wikipedia.org/wiki/Sonic_weapon

    • ehrichweiss says:

      Yep, it’s 100% legit. I’ve got one of the knockoff “grok boxes” from back in the early 90’s and a legit Neurophone from Flanagan himself. The knockoff works but not as well as Flanagan’s. If you look around you can find several different sets of schematics for them with different abilities. They’re very cool for learning.

      • Vanzetti says:

        There is another method that falls into the “hey kids, don’t try this at home!” category. Circa 1972, several experimenters were using micropower frequency injection with conductive pads, one applied to the lower back and one applied to the neck/shoulder area.

        Caveat: I haven’t done it, I did not see the demo and the idea gives me the heebie-jeebies – I ain’t trying it. The modulation was at high frequencies, and the audio signal was somehow pulled out by the CNS. I believe there was another variant that simply had two pads near the lower back.

        Although I know nothing of what happened to the project, I know that it was used successfully to send audio cues to individuals without the use of headphones. And I don’t mean “tin-foil-hat brain control” cues, just regular speech at low to medum fidelity.

        Another interesting project was using two reasonably high power narrow beams of ultrasonic audio to heterodyne at a location, which would mix and be filtered by humans as speech or music. It’s a cool party trick with no particular application, and you can do it home using ultrasonic frequency shifters.

        You can also go the other way. Look into infrasonics – it turns out that elephants (and I think whales do as well?) communicate at very low audio frequencies just as bats do at high frequencies. The data rate drops, but really, there’s a lot you can do at <20 hz… and in the RF bands, there are lots of folks moving data around at glacial speeds for various reasons.

      • Vanzetti says:

        PS – I believe that the frequencies were UHF rather than ultrasonic.

  2. Mode of operation = ?

    • Heterodyning and physical conduction of sound to the cochlea. No pyramids or time cubes needed.

    • akismet-a8c1e1fc23835324d400ef9acfc5d14b says:

      AFAIK, sound is modulated on an ultrasonic carrier wave that is dismissed on “hard” objects (e.g. head bone). I’m no expert though (obviously)

    • akismet-a8c1e1fc23835324d400ef9acfc5d14b says:

      (oops sorry for double post [August 7, 2012 at 11:43 am] )

    • neurophone says:

      (mods, clicked the ‘report comment’ link instead of ‘reply’ by accident. Sorry!)
      Here’s the mode of operation (mostly copied from my comment below):
      – It replaces the rising and falling edges of the audio signal wave with edges that have the _slope_ of a 40-50kHz ultrasonic wave. The 40kHz carrier is unimportant, the slope is key.

      – It then double differentiates and highpass filters the result. This mimicks what would happen if you fed the signal into an antenna and then received the electromagnetic waves with your brain! The double-differentiated signal is now converted to mechanical energy with a piezo speaker, bypassing the brain’s radio receiver.

      The way the piezos are wired in the TL494 Neurophone (maybe also in the real ones) creates an electrical “Lilly Wave” that stimulates the nerves as if they were getting signals from other nerves.

  3. Chris C. says:

    I love it when pseudoscience debunks itself:

    “Lastly, you’ll probably find the signal is easiest to hear ‘in your head’ with the electrodes near your head.”

    Exactly. Because what they’re claiming, that it’s picked up and transmitted by the nervous system to some “little known part of the brain”, isn’t true.

    Physical conduction of sound to the inner ear is well known and documented. Most folks can hear up to about 30khz or so if the transducer is pressed against the head. And modulated ultrasonic carriers will be partially demodulated, which is the only reason this works.

    • acomputerdog says:

      so what your saying is that it does work, just not the way they are claiming?

      • Chris C. says:

        It works to a limited degree, just not as well or in the manner claimed.

        Even if the bones in the ear are fused or damaged (resulting in deafness) you can bypass them by transmitting amplified sound through the cranium to the cochlea. I believe there’s commercial hearing aids that work on this principle.

        But Flanagan said that using this device, any nerve can pick up sound, transmit it to the brain, and the user can hear it. Just not true, sorry.

        • Jayduey says:

          Not quite true. I actually made one of these and used it. By using the piezos not as contacts, but separate and using foil pads (because too wasn’t sure if it was just vibration from the piezos themselves), it still worked.
          The piezos are to limit current and dc voltage, so they needn’t be the contacts themselves.

          • RobH says:

            I know this is old, but the Neurophone interfaces with the saccule. The cochlea can be completely missing and if the saccule is intact the individual will “hear” the ultrasonic frequencies coming from the transducers. In fact, when Flanagan was applying for his patent the patent office told him if a certain deaf patent inspector could hear using the Neurophone they would award the patent. For the first time the deaf patent inspector heard classical music and wept. The patent was awarded only to have our wonderful government attempt to classify it which Flanagan successfully fought and won his right to the technology. The saccule gland has a neuronal connection to the brain, both to the hearing center as well as to the long-term memory and the subconscious. In 1991 a scientist, Martin Lenhardt, discovered the foundation of this transmission path for ultrasound. We share this ultrasonic “hearing” ability with dolphins.

  4. hospadar says:

    mode of operation = POWER OF THE PHARAOH

  5. hospadar says:

    what would actually be cool, but hard, would be something that takes ultrasound and steps down the frequency but preserves other sound characteristics so it can be heard. The audio equivalent of ultraviolet film.

    • lovecraft says:

      Isn’t that vaguely how an MRI works, but in 3 dimensions with magnetic waves instead of sound. Kind of the way Xrays and radar are related.

    • Chris C. says:

      Have seen that before. Think there was a project for it in an old issue of Radio Electronics, that would let you listen to bats, insects, freon leaking from pinholes, etc. It’s a matter of heterodyning, same way a radio shift RF frequencies down.

      • n0lkk says:

        POTS cables are pressurized. a long time ago a long haired man was walking down the alleys & streets wearing headphones with a parabolic reflect pointed towards the sky, am odd sight in a small town. I stopped to ask what’s up. He said he was with the telco & was listening for the ultrasonic sound made by gas leaking out of fin holes in the cable armor.

      • fcassia says:

        you write: “POTS cables are pressurized. a long time ago a long haired man was walking down the alleys & streets wearing headphones with a parabolic reflect pointed towards the sky, am odd sight in a small town. I stopped to ask what’s up. He said he was with the telco & was listening for the ultrasonic sound made by gas leaking out of fin holes in the cable armor.”

        Not *all* POTS cables are pressurized. Apparently, that hasn´t been used in ages… must be really really old cabling…

        Ten years ago this was written:

        http://ecmweb.com/content/understanding-air-pressure-systems-osp-cabling

        “As an OSP system designer, you must be prepared to encounter *older system designs and outdated, but operable, technology* on any future project. ”

        “BICSI’s Customer-Owned Outside Plant Design Manual is a good source for referencing this *obsolete*, but very important, method of OSP cable protection.”


        “Most conduit routes that feed metropolitan areas still use air pressure systems to protect their cables. The high cost of replacing these large cables would make it difficult to completely eliminate such systems, so it’s more cost-effective to maintain them. Advances in air pressure system technology have changed all of that, though. The introduction of plastic insulated conductor (PIC) insulation and filled cable designs has eliminated the need to build or add additional air pressure systems onto a network.”

    • anon says:

      Not hard at all if you do it with brute force: 192kHz input sound card, ultrasonic-capable microphone and a pitch shifter plugin. Shift 2 octaves down and enjoy. :-D
      Could do to a lesser extent with 96kHz.

      Heterodyning doesn’t do this, heterodyning only demodulates modulated signals but demodulating isn’t the same thing as listening (what you would hear would be a signal derived from the frequency shifts of the sounds, not the sounds).

      There’s no easy way to do it in analog as far as I’m aware. Certainly not with anywhere near the same quality.

  6. torcue says:

    @ Chris c
    For example.a 30khz carrier signal with a 15khz amplitude modulation will sound at 15 kHz?

  7. Gremlee says:

    It does amuse me when people dismiss alternative theories just because it’s what the scientists tell us what we should do. I’d have expected that people on this site were a little more open minded towards new theories or thoughts. After all isn’t that how new inventions begin?

    • imajeenyus says:

      We don’t dismiss them because “it’s what the scientists tell us what we should do”. We dismiss them because we KNOW enough science to enable us to realise that a particular claim or theory is bunk, or that it may work, but not in the way described.

      • Gremlee says:

        We know enough about science? Ha ha I’d like to think we do as well but it just isn’t the case I’m afraid. We have gaping holes within physics (which most academics will agree with) so how can we know enough about science?
        Anyway, I don’t want to sound like a conspiracy junkie.

      • Dax says:

        “We have gaping holes within physics (which most academics will agree with) so how can we know enough about science?”

        That’s appeal to ignorance, which is a logical fallacy. Not knowing something doesn’t make something else valid or true, or even plausible.

        “Anyway, I don’t want to sound like a conspiracy junkie.”

        But you still do.

    • Dax says:

      In science, the term “theory” refers to “a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment.” It also has to make falsifiable predictions with consistent accuracy across a broad area of scientific inquiry, and production of strong evidence in favor of the theory from multiple independent sources.

      These alternative “theories” you’re talking about are just employing the Stetson–Harrison approach to science.

      • Gremlee says:

        I suspect that there are other websites for discussing this very topic so I’ll leave it at that. I was just surprised that people on this site were not open to other ideas that’s all. Just because we can’t detect something doesn’t mean it doesn’t exist.

      • anon says:

        When what you *can* see things and those things you can see do explain everything about the world, it *does* mean the other things don’t exist.

      • Kaj says:

        If you cannot detect, demonstrate, or otherwise infer the existence of something as being a part of reality, it is indistinguishable from something that does not exist.
        Therefore, you are unjustified in believing it to be true.

        If it cannot provide a falsifiable or testable hypothesis, it is meaningless conjecture.

        So, while I’m open to discuss possible hypothesis, I am also willing to dismiss without evidence that which is asserted without evidence.

    • Chris C. says:

      The Neurophone’s been around since 1958. It’s hardly new science, just bad old pseudoscience that resurfaces from time to time.

      And I’m not dismissing this because of what anyone tells me. In fact, I’ve built one. I speak from experience on what it can and cannot do, and that it doesn’t work as the inventor claims. Through that and other experiments, I eventually learned that “suppressed” inventions are utter nonsense at least 99% of the time; and I’ve looked at pretty much all of them. Hope you gain that wisdom eventually too.

      The only debatable science I still hold hope for is Lawrenceville’s fusion, Mach Effect thrusters, and Coolchips.

    • Eirinn says:

      “It does amuse me when people dismiss alternative theories just because it’s what the scientists tell us what we should do.”

      It doesn’t amuse me that you’re making this comparison; which is for me, absolutely false.

      You’re passing an argument based on ridicule which is almost as stupid as saying “i don’t like you because i just said so”.

    • faeion says:

      It does amuse me that each one of you got trolled so bad.

      • Eirinn says:

        What annoys me greatly is that I failed to recognize a standard fallacy.

        Whether or not science has uncovered everything or not, does not make the original statement true. Nor is it remotely important.

        The burden of proof is STILL on the original statement holder.

        I feel like a complete idiot now :)

  8. akismet-a8c1e1fc23835324d400ef9acfc5d14b says:

    Actually this works, exists already, and is sold commercially : http://www.holosonics.com/technology.html

    I tried another brand and it’s quite impressive : very narrow beam,, sound “bounces” off objects. Really nice.

    I think it’s the same technology behind the sonic weapons on US naval ships (http://en.wikipedia.org/wiki/Sonic_weapon), a bit less loud though :)

    • Chris C. says:

      Difference is that Flanagan claims the ultrasonics from the Neurophone can be picked up and “heard” by any nerve in the entire body.

      Holosonics certainly doesn’t make that claim. It’s real science, it works, and is picked up by the ear.

      • Jesse Congdon says:

        See, and that is the difference I failed to pick up on when I was putting together the post. All the searches involving “Flanagan” and “Neruophone” were red herrings. Glad to know it IS real science… under a thick veil of pseudo.

  9. n0lkk says:

    I wonder why the name for that “little-known part of the brain” was not given? In the event it’s known about brain scientists, it most likes has a name. I always figured science has long used block conversion/hetrodyning to learn about what sound does exist outside the human range of hearing.

  10. Rollyn01 says:

    Bone-conduction technology using ultrasonics. Reading this would make one think that this guy didn’t know much about human anatomy, much less neurology. That “little part of the brain” is called the parietal lobe and it’s not that little.

    As far as how this would have worked with radio waves, most likely it was stimulating some of the muscles near the eardrum causing them to vibrate to produce sound in the ear. Kind of how your muscles could be stimulated to contract during an MRI. This may be the “nerves” they was talking about.

  11. Johnny O. Farnen says:

    Meh. This is just a cohclear implant….without the implant.

    I’ll stick to my faraday caged mancave and my foil helmet….

  12. Bob says:

    Old as the hills!
    Google: JS&A Bone Phone

  13. zzzomb says:

    It is a neat little gimmack. The key clue here is that he is using not just any pad of metal, but is using a piezo element connected to the piezo ceramics, not just the metal. The piezo effect is physically moving the piezo ceramics to make sounds just like the speaker that makes beeps inside your wrist watch.

    The trick is that it is using skin conductance touching on the metallic side of the piezo element to complete the output part of the circuit, so it won’t work until you press both against your skin. Then it simply becomes 2 piezo speakers in series. It you wire the 2 metallic sides of the piezos to each other it will work permanently.

    • zzzomb says:

      That is, if you wire the 2 metallic contact sides of the piezos to either other, it will work like plain old piezo speakers whether it is pressed against your skin or not.

  14. asdf says:

    That ultrasonic “audio” carrier is also basis for the speech jammer project from a few months ago.

    http://servv89pn0aj.sn.sourcedns.com/~gbpprorg/mil/speechjam/

    https://sites.google.com/site/qurihara/top-english/speechjammer

  15. Dias says:

    Couldn’t most of this device be easily emulated with software?

  16. PlastBox says:

    Kaj says:

    “If you cannot detect, demonstrate, or otherwise infer the existence of something as being a part of reality, it is indistinguishable from something that does not exist.
    Therefore, you are unjustified in believing it to be true.”

    So much win in so little text, I feel congratulations are in order!

    • Kaj says:

      Thanks PlastBox, it’s nice to hear I communicated the thought well.

      Cheers
      ;)

      • Volkemon says:

        I second.

        “” If you cannot detect, demonstrate, or otherwise infer the existence of something as being a part of reality, it is indistinguishable from something that does not exist.
        Therefore, you are unjustified in believing it to be true.

        If it cannot provide a falsifiable or testable hypothesis, it is meaningless conjecture.

        So, while I’m open to discuss possible hypothesis, I am also willing to dismiss without evidence that which is asserted without evidence.””

        I copied that it was so good. Thank you.

      • Kaj says:

        @Volkemon

        Thanks man! Copy in good health ;)

  17. JB says:

    I’m mostly interested in the application for a “non-contact” hearing aid. I wonder how much power would be needed to project a sound beam for a hearing impaired person who doesn’t want to use a conventional hearing aid. Time to experiment…

  18. mr foo says:

    A little known portion of the brain? It can only be – Shatner’s Bassoon!

  19. NewCommentor1283 says:

    in order for this to work, the recieving brain needs a plugin!!!

    (code to redirect signals recieved from the spine into the sound module aka hearing)

    but of course, the manufacturer completely removed the service and diagnostic ports. looks like we need a redesign of the human body!

    updates for everyone! lolz

  20. John Lewis says:

    Nothing at all bogus about the original Flanagan Neurophone; I built one in high school back in the early 80’s as for a school project. It really worked.

    However it didn’t use ultrasound directly. What it used instead was an interesting circuit that would generate a series of pulses which were conducted into the skin using special electrodes. While I suppose ultrasound might work just as well, it was not the way Flanagan did it.

    The theory was that the pulses looked enough like the way sound pulses coming from the inner ear do that the brain figures out that they must be sound and then routes them to the appropriate area of the brain for decoding.

    It is something similar to what someone with synesthesia (someone who can “feel” sounds or “hear” color) goes through all the time except this is an artificial form of it.

    I’ll be happy to dig up some details if anyone is interested.

  21. 333dan says:

    John,
    I’d also love to know more about your design. What did you use for electrodes? What did your schematic look like?

  22. DBHellmith says:

    To me it seems more like bone conduction, which does work

  23. neurophone says:

    The TL494 Neurophone is indeed the wrong way to do it.

    It turns out Flanagan’s Neurophone does two things:

    – It replaces the rising and falling edges of the audio signal wave with edges that have the _slope_ of a 40-50kHz ultrasonic wave. The 40kHz carrier is unimportant, the slope is key.

    – It then double differentiates and highpass filters the result. This mimicks what would happen if you fed the signal into an antenna and then received the electromagnetic waves with your brain! The double-differentiated signal is now converted to mechanical energy with a piezo speaker, bypassing the brain’s radio receiver.

    The implication of this is that there are bits of our brain that act as a radio receiver with 100kHz bandwidth, and can process incoming audio. Which is crazy.

  24. neurophone says:

    Cross-posting from the blog, for all the commenters here interested in the updates:

    It turns out “earplug-style” (in-ear-monitor) headphones affect the brain in at least some of the ways a real Neurophone does. If you want the freedom of thought that the pink-noise Neurophone brings, an even more effective way of getting it turns out to be the following:

    Get some earplug-style headphones. Make sure they produce a good seal. One person used Sennheiser CX150s, which cost $18-30.

    Plug them into a pink noise generator. Use a good one! (Like this design: http://sound.westhost.com/project11.htm )

    And that’s it! If you want to sleep incredibly well, try this at night. A bit of medical tape under the ears will hold the cables in place.

    One heads-up: For maximum fidelity of the pink noise signal, it may help to use a headphone amplifier between the headphones and the pink noise generator. This is an easy-to-build design:

    http://headwize.com/projects/cmoy2_prj.htm

  25. neurophone says:

    Update: Maybe I wasn’t so far off after all. Neurophone inventor Patrick Flanagan has since confirmed the TL494 Neurophone design CAN produce Neurophone effects, though it’s still probably not as good as the real thing.

    Some research suggests this is why it works: the TL494’s square-wave output gets differentiated by the piezos (which are capacitors), producing a “Lilly wave”-like signal that mimics signals produced by nerves. (The Lilly Wave, as far as I understand, is a sharp positive spike followed by an equal but negative one. The idea is the first peak transports something, I think ions, across the barrier between nerves while negative spike brings them back so the nerves can use them again.)

  26. fivef says:

    So after I have read all the comments.
    Has anyone successfully built a neurophone (this or another one)?

    I know that it works because about 10 years ago a neighbor, who has a company selling devices like this, gave me a demonstration.
    It was a demo for group synchronisation. We were 10 people sitting around a table. One of these persons put the pads on his skin. (I think it was put on the stomach)
    Then everyone held the hands of his two neighbors and everyone (including me) heard the music playing. He explained that the sound is conducted by the body liquids and the bones.

    So as I know for sure that its working, (Working defined as put electrodes on the skin and hear something no matter where the electrodes are placed)
    I want to build such a device!

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