A technical report from the University of Michigan offers a stunningly simple theory for the source of the Cuban "sonic attack": a pair of eavesdropping devices too close to each other and tripping the ultrasound that ironically was supposed to make their presence quiet.
More importantly, it might not have been done with malicious intent.
"It doesn't prove it's the cause," Kevin Fu, an associate professor at the University of Michigan and one of the co-authors of the study, cautioned. "It's a correlation. But to us, it seems like a strong correlation."
A recap: Last September, the State Department recalled 21 American employees from the U.S. embassy in Havana. These employees, along with three Canadians, reported dizziness, cognitive difficulties, headaches, and hearing loss, among other medical issues, according to an official statement made by Secretary of State Rex Tillerson. The victims of what was being termed a "sonic attack" reported hearing a high-pitched sound that made them physically ill.