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Researchers Provide Likely Explanation For the 'Sonic Weapon' Used At the US Embassy In Cuba (ieee.org)
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."
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."
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?
Life is not for the lazy.
Someone must have "left a few of these "Things" somewhere in the building:
https://en.wikipedia.org/wiki/...
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
They looked for stuff like that, and didn't find it. Unless they are wholly incompetent, that's not the problem.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
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.
Never attribute to malice that which is adequately explained by stupidity (Although don't rule out malice)
I had a dream, bright and carefree, but now there's doubt and gravity
Why would an IMD product be more harmful than any other audio signal of normal intensity and spectral content? That question needs to be answered before this theory can be taken seriously.
Standing waves. I've been spending the last three years working in this space with audio processing, before I even open the paper I said to myself "I bet intermodulating waveforms" is a factor and there it was on the second page. I will most certainly read this whole paper however I thought I'd share some of my experiences that were a by-product of what I was trying to understand.
Out of curiosity I tried the experiment on myself and a few friends and found that if you hit the right frequency with a person, they will practically hit the roof and run away if they have any form of Tinnitus. I did a spectral analysis of the waveform and the best I can describe it is like audio teeth, waveforms with a specific Q, amplitude and frequency separation. I could'nt see anyone handling more than a few seconds of it, I have no doubt you would be very sick in much less than a minute.
If there were two devices they would cancel AND reinforce certain audio spectrum within the human hearing range thus you would get a combination of modulating and standing waveforms would be *really* disorientating, anything more than 5watts at that frequency range would be nasty. Just moving around in the room would make it oscillate.
It's not just humans and please don't hold this against me, I love dogs too, but not when they bark until 5am and sleep all day while I am driving down a freeway fatigued. Complaining to neighbors doesn't work but an intermodulating waveform oscillating between 23k and 25k works in under 10 seconds. No neighborly confrontation required.
The last thing I found is that it doesn't have to be actual damage to your hearing to produce the effect. I have my hearing tested often, I know exactly where the damage is and the effect is not necessarily related to damage.
A final point though is wind turbines. I think the effect is the same however it is intermodulating infrasound with very long waveforms relating to the characteristics of the turbine blades in different turbines interacting with each other. I would not live near these devices any more than living next to a main road, it will slowly make you sick.
Obviously my pithy experiments aren't controlled so I'm interested in what this paper has to say, maybe it can answer some questions I have.
My ism, it's full of beliefs.
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...
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 in return for access to the information they gathered.
This being intelligence stuff it's all a bit legally dubious even in the West. God knows what happens in places where the intelligence agencies can openly ignore the law like China, Russia, Cuba or North Korea.
For example Peter Wright described a plan to convert a bust of Lenin into an ultrasound reflector - the idea being the reflected ultrasound would be modulated with an audio signal, the audio signal being the sound around it -
https://spyinggame.me/2012/07/...
As to what else went on inside the embassy, perhaps MI5 picked it up by electronic means, perhaps not. Peter Wright describes a delicious plan devised by MI5 in the 1950s, using new technology to modify an ordinary object so that it would reflect sound waves; carrying no transmitter or receiver itself, the object was virtually undetectable. Why not modify some valuable object along these lines and give it to the Soviet ambassador? Wright consulted someone who knew the ways of the Soviet diplomatic community and had also been with MI5: Klop Ustinov, father of the actor. Ustinov suggested a bust of Lenin or a model of the Kremlin, something so sacred that the Soviets wouldn't be tempted to sell it. Lenin was vetoed ("the smooth contours of Vladimir Ilyich's skull were too rounded to be sure of reflecting sound waves," Wright tells us) and ultimately the FO abandoned the project, for reasons we do not learn.
I.e. the idea of using a microwave or ultrasound reflector as a remote microphone has been around for some time.
echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
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 absence of any credible cause makes this difficult to believe in. Sure the Russians and Cubans are capable of this sort of thing, but that the U.S. failed to detect it is difficult to believe.
Bruce Perens.
I lost my hearing back in '84 to spinal meningitis. I now have a cochlear implant to hear things. I'm curious if these waveforms would bother me because my hearing isn't "natural." Push comes to shove, I can either connect a music source in-line, which blocks all external sound, or just turn my CI off. Would that be a useful defensive mechanism?
I lost my hearing back in '84 to spinal meningitis. I now have a cochlear implant to hear things. I'm curious if these waveforms would bother me because my hearing isn't "natural."
That's a really good question, short answer is I don't know but I could have a guess.
Push comes to shove, I can either connect a music source in-line, which blocks all external sound, or just turn my CI off. Would that be a useful defensive mechanism?
I bet that feature comes in handy sometime ;)
I think it will depend on three factors: 1. the microphone will have a non linear response in a limited range, 2. the circuitry of the device and 3. the frequency spectrum it offers you.
I think that these devices are mainly aimed at you being able to hear other people so the audio spectrum would be concentrated around 3-4khz where human speech roughly resides so therefore I suspect you would be pretty safe from those sorts of attacks. However if the frequency response is extended and the device produces a harmonic you might perceive it but not it's effects. That's my guess.
I finished reading this paper, fascinating. The spectral analysis is very similar to what I saw, I think my HF drivers and DACs are a bit better and can produce higher outputs (not that you need it) than what they have and also the distance *between* the drivers is a factor as well.
My method was different than what they were using because I was trying to understand perception to make things sound pleasing not to destroy people. That said, the paper concludes it wasn't on purpose and if you think about it, that's reasonable. I'd imagine there was a lot of pressure and focus on those diplomats it's not unreasonable to conclude there was a bunch of equipment in that room causing all sorts of unwanted interactions.
My ism, it's full of beliefs.