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United States Science

Researchers Provide Likely Explanation For the 'Sonic Weapon' Used At the US Embassy In Cuba ( 112

An anonymous reader quotes a report from IEEE Spectrum: Last August, reports emerged that U.S. and Canadian diplomats in Cuba had suffered a host of mysterious ailments. Speculation soon arose that a high-frequency sonic weapon was to blame. Acoustics experts, however, were quick to point out the unlikeliness of such an attack. Among other things, ultrasonic frequencies -- from 20 to 200 kilohertz -- don't propagate well in air and don't cause the ear pain, headache, dizziness, and other symptoms reported in Cuba. Also, some victims recalled hearing high-pitched sounds, whereas ultrasound is inaudible to humans. The mystery deepened in October, when the Associated Press (AP) released a 6-second audio clip, reportedly a recording of what U.S. embassy staff heard. The chirping tones, centered around 7 kHz, were indeed audible, but they didn't suggest any kind of weapon. Looking at a spectral plot of the clip on YouTube, Kevin Fu, a computer scientist at the University of Michigan, noted some unusual ripples. He thought he might know what they meant.

Fu's lab specializes in analyzing the cybersecurity of devices connected to the Internet of Things, such as sensors, pacemakers, RFIDs, and autonomous vehicles. To Fu, the ripples in the spectral readout suggested some kind of interference. He discussed the AP clip with his frequent collaborator, Wenyuan Xu, a professor at Zhejiang University, in Hangzhou, China, and her Ph.D. student Chen Yan. Yan and Xu started with a fast Fourier transform of the AP audio, which revealed the signal's exact frequencies and amplitudes. Then, through a series of simulations, Yan showed that an effect known as intermodulation distortion could have produced the AP sound. Intermodulation distortion occurs when two signals having different frequencies combine to produce synthetic signals at the difference, sum, or multiples of the original frequencies. Having reverse engineered the AP audio, Fu, Xu, and Yan then considered what combination of things might have caused the sound at the U.S. embassy in Cuba. "If ultrasound is to blame, then a likely cause was two ultrasonic signals that accidentally interfered with each other, creating an audible side effect," Fu says. "Maybe there was also an ultrasonic jammer in the room and an ultrasonic transmitter," he suggests. "Each device might have been placed there by a different party, completely unaware of the other."

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Researchers Provide Likely Explanation For the 'Sonic Weapon' Used At the US Embassy In Cuba

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  • by DigiShaman ( 671371 ) on Friday March 09, 2018 @09:15AM (#56232909) Homepage

    Who would be using the transmitter? Who would be using a jammer. Moreover, which nation-state/s would bother with using ultrasonic in an age of cheap RF based technologies?

    • Re: (Score:3, Interesting)

      by Anonymous Coward

      It looks like the spy agencies working there at the embassy did it to themselves and everybody else working there. CIA puts their thing in. The NSA theirs. Some military intelligence puts theirs in.

      Cubans sit back and eat popcorn.

      The Cuban government must be laughing their asses off.

      • by K. S. Kyosuke ( 729550 ) on Friday March 09, 2018 @09:52AM (#56233065)
        So far, so good, but...

        Cubans sit back and imagine eating popcorn.


      • In reality, the Cubans suggested that the US State Department to bring the FBI in to see if they could get to the bottom of the problem. (No, I don't know why the Cubans might think the FBI might know anything about sonic weapons).

        Do the Cubans have the US offices and residences bugged? Of course they have the US offices and residences bugged. Why would they not? You can probably hear the plumbing talking to the air conditioners and every other electronic device if you listen real hard at night. Did th

    • by PolygamousRanchKid ( 1290638 ) on Friday March 09, 2018 @09:27AM (#56232949)

      Who would be using the transmitter?

      The Cubans.

      Who would be using a jammer.

      The embassy staff . . . to thwart the Cubans.

      Moreover, which nation-state/s would bother with using ultrasonic in an age of cheap RF based technologies?

      Folks who don't want their bugs found because they are constantly transmitting.

    • If anything, if the pulses are due to phase cancellation it's because it's some sort of sonic beamforming weapon - barely audible to everyone but the victim. And the perceived frequency may not be ultrasonic or even in the same range as the individual beams. The recording device would not be in the place that puts everything in phase - it would be highly targeted.

  • by Anonymous Coward

    Interference caused by multiple ultrasonic toothbrushes running simultaneously.

  • by PolygamousRanchKid ( 1290638 ) on Friday March 09, 2018 @09:22AM (#56232931)

    Someone must have "left a few of these "Things" somewhere in the building: []

    • by WallyL ( 4154209 )

      Someone must have "left a few of these "Things" somewhere in the building: []

      Brings new meaning to the expression, "Internet of Things," doesn't it?

    • A couple of 1970-style ultrasonic intrusion alarm sensors might make the same sounds by hetrodyning together. It is more than likely that such things could be found in the embassy. The embassy building was constructed in '53 and re-occupied by the U.S. in '77.

      I've seen no credible explanation for the injuries reported to have occurred to personnel there. The U.S. has monitored for various sorts of energy, RF, sound, light, since Theremin's Great Seal Bug (the "Thing") which the post above refers to. The abs

  • They looked for stuff like that, and didn't find it. Unless they are wholly incompetent, that's not the problem.

    • They looked for stuff like that, and didn't find it.

      "Testing shows the presence, not the absence of bugs" -- Edsger W. Dijkstra

      Unless they are wholly incompetent, that's not the problem.

      Like Dijkstra says, they can only find what they are looking for.

      If there is something they don't know about . . . they don't know how to look for it . . . so they can't find it.

      So the Cubans have something our spooks don't know about. We have only noticed the "collateral damage" it has cause . . . not the thing in itself. Kinda sorta like looking at the traces left by wacky sub-atomic particles.

      • LMOL yeah the cubans have something the NSA does not know about....think about that for a second....
        • They have the whole world to draw from, perhaps someone loaned it to them for a field test.
        • Rogue states like Cuba and North Korea don't necessarily need to develop this sort of thing for themselves - they could just let in Russian or Chinese intelligence agents who'd have something they'd need to test.

          It's like the reverse case of the Cold War where a lot of US allies - naming no names but the CPU in your cellphone or laptop was either invented, designed or manufactured in one - allowed US intelligence personnel in to test some clever intelligence gathering ideas on the USSR, PRC or their allies

      • So the Cubans have something our spooks don't know about.


    • by Moskit ( 32486 )

      They _said_ they did not find. Saying is not the same as not finding, especially for politics/espionage/...
      Basic example - sometimes you leave a known bug to disseminate wrong information.

  • Also based on 6 seconds of audio and nothing else, doesnâ(TM)t rule out an attack or deliberate emplacement for a particular purpose, and doesnâ(TM)t change the outcome.

    • Except of course all the experts in audio, ultrasound and RF say such a weapon is impossible to build. What the US state department described was a sound weapon that couldn't be heard, destroyed hearing and affected peoples minds and was targeted as specific people. Sound, ultrasound and RF cannot be controlled in a manner like that or cause those symptoms and that kind of distance.

      The state department cooked up a fanciful weapon to describe these events but everyone that was an expert said it was impossibl

  • Heinlein's Razor (Score:5, Insightful)

    by Oxygen99 ( 634999 ) on Friday March 09, 2018 @09:37AM (#56232997)
    Never attribute to malice that which is adequately explained by stupidity (Although don't rule out malice)
  • If only someone at the time had put this together and stated it publically []. What dosent add up here is the sensors mentioned in the white paper are all very low power. You dont cook peoples thinking jelly with a half watt transmitter or two throughout a building, though they do have the potential to be as annoying as old fluorescent lights. To mess up people you would need extremely high power sensors running all the time, something I find extremely hard to believe "was accidental with 2 or more parties
  • The first paragraph says ultrasound doesn't travel well in air and does not cause pain. Second paragraph suggests an ultrasound transmitter and possibly jammer? What would be the point of any of these devices if they can't transmit very far?

  • "This technical report analyzes how ultrasound could have..."

    So it's not surprising you came up with a result that supports that conclusion. It would be more convincing if you were looking for something else and then came up with that conclusion, when you eliminated other explanations.

    Why China was involved is curious thing...
  • by ctrl-alt-canc ( 977108 ) on Friday March 09, 2018 @10:30AM (#56233229)

    Ancient TV RC used ultrasound transmitters. They are no more used in the civilized world, but maybe in Cuba are still there. People of the embassy were busy with two remote controls in a fight to decide which TV sitcom to view and...

    • by PPH ( 736903 ) on Friday March 09, 2018 @11:09AM (#56233389)

      Back in my days working on secret stuff, meeting room windows were equipped with piezoelectric transducers used to defeat laser inferometer microphones. It's possible that our embassy was so equipped. This would explain one ultrasonic source. Possibly even multiple sources in rooms with lots of windows and poorly installed systems.

  • by YayaY ( 837729 )

    So, it was an ultrasonic weapon that use intermodulation as a targeting mechanism. Suggesting that this just happened by accident at US embassy is ridiculous at best.

    If the OP explanation was probable, it would also occur randomly at other location. We haven't heard about that so far.

  • by pele ( 151312 )

    Now we wait for diplomats to provide a swift and loud apology just like they switfly and loudly rushed to accuse them of having created a sonic weapon to attack their staff.

    Oh btw how efficiently does ANY sort of sound travel through bullet-proof glass that they have on pretty much all embassies?

  • Audio engineers and neuroscientists have been saying this since the story first came out: it's not a sonic weapon. It's not some "unknown type of sonic weapon" or a "sonic weapon that utilizes unknown physics" or "leaves scientists baffled by new sonic weapon." It's almost certainly a microwave transmission, probably to energize a passive listening device like The Thing []:
    It's highly directional and so only affects one person in a room, without anyone else noticing anything. Moving their heads from one posit
    • In addition, the AP clip was debunked: []

      Cell phone recordings of the alleged sonic attack were provided to an Associated Press reporter by an anonymous source in the State Department. But the sounds were identified by Yamile González Sánchez, an official at the Ministry of Public Health, and physicist Carlos Barceló Pérez, a professor at the National Institute of Hygiene, as those made by local insects, which they recorded on the scene. Moreover, the sounds, all in the audible range (about 7 kilohertz), would have overdriven the microphone—preventing it from recording—if they were loud enough to damage hearing.

      So Wu was analyzing the sound made by cuban crickets.

  • "Among other things, ultrasonic frequencies -- from 20 to 200 kilohertz -- don't propagate well in air"

    That's why dogs can hear my dog whistle from about a mile off, right?

    • No, they hear it because it's fucking loud, and can be painful or damaging to dog's ears at close range. Stop using it, asshole.

  • This tech has been around for decades. Its currently in use.

    Here is a demo from decades ago: []

    Ultrasonic beat waves/interference is what this looked like from the beginning. Reverse engineering isn't necessary to discover this.

  • The explanation of the number of Ph.D. scientists it took to explain "Duh, it's a Hetrodyne!", and then to not even use the correct language (intermodulation distortion is an effect of hetrodyning signals in a supposedly linear circuit, not the hetrodyne itself), is really pathetic.

    You could get a better explanation from the average radio ham in clearer language.

interlard - vt., to intersperse; diversify -- Webster's New World Dictionary Of The American Language