The "ultrasonic attack" really deserves a few dozen scare quotes at this point, people with experience of using ultrasound on humans deem it unlikely to actuall

The "ultrasonic attack" really deserves a few dozen scare quotes at this point, people with experience of using ultrasound on humans deem it unlikely to actually cause harm in any covert way, and I do trust the medical profession to find pretty robust limits on how dangerous ultrasonic devices are. So given that there is no convincing reason to believe ultrasound has anything to do with it, they've now demonstrated a way to make audible noise as a consequence of interaction between two ultrasonic sources. They chose this particular (obscure) way of getting audible sound from an ultrasound emitter because a journalist sent a video of a sound whose relevance is that it was recorded on Cuba. And the great result is that now you need at least two ultrasound emitters, one of which is a bulky 155 dB emitter just lying around undetected in the homes of American diplomats. I don't see how the explanation of a minor problem with the ultrasound theory is any great advance.