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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."
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
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.
Well, I can see you totally bought into that whole "were completely unaware of each other" bullshit theory. Now how about a dose of reality.
Given all the bullshit that has been going on with Russia, it's not so fucking far-fetched to believe this was an actual legitimate attack rather than some multi-org "oops" that just so happened to target a US embassy sitting in the middle of a communist country. It's not like sonic attacks are some newfangled thing no one has ever heard of or used. We've been testing LIPE and PASS weapons for years, to which the full effectiveness of such a weapon would be classified. And combining frequencies to produce a specific end-result isn't far-fetched either, especially if you already know your attack specifically works in conjunction with known countermeasures (jammers).