Back in October, AP reported that they had “obtained a recording of what some U.S. Embassy workers heard in Havana,” a high-pitched whine “sort of like a mass of crickets.”

A new technical report tests the idea that the audible sounds recorded by AP in Cuba could have been caused by two (or more) ultrasonic sources (a less technical description is here). What the paper shows is that sounds similar to those in the AP report can be produced from the interference of one ultrasonic source on another. This much seems convincing. I don’t have a deep understanding of the physics, but the real-world demonstration is hard to argue with.

But just because the sound can be reproduced this way doesn’t mean it was produced this way. I have seen “Eye of the Tiger” played on dot matrix printers. That doesn’t mean Survivor recorded it using dot matrix printers.

Importantly, the researchers don’t claim that the sound was produced by ultrasonic interference, only that it could be produced this way:

We assume that the sound came from ultrasound, then work backwards to determine the characteristics of the ultrasonic source that would cause the observed audible sensations.

Note that they only show that the recorded sound, which is not known to be the cause of anything, can be reproduced this way. This is a nice proof of concept, but it is in no way evidence that the diplomats were attacked at all, much less by a sonic weapon. The researchers don’t show, try to show, or claim that there is any way the ultrasound used to reproduce the frequency could have caused any, much less all, of the symptoms experienced by the embassy staff.

In other words, they have shown that ultrasonic interference is a plausible explanation for the sounds that AP recorded, not that it is a plausible explanation for the diplomats’ symptoms. It isn’t; we already know this.

Neurologists who examined the injured diplomats published their findings in JAMA [25], and suggest that the neurological damage is real. However, there are limitations to the retroactive study [18]—namely, causality is difficult to establish without a control trial or elimination of other null hypotheses. Our report does not itself contribute any new findings on neurological harm.

Can audible sounds can be produced from interfering ultrasonic sources? Apparently they can. But as far as foreign policy is concerned, that’s the wrong question. What we should be asking, and few news sources are, is “Were embassy personnel attacked?” If the answer to that turns out to be yes, then we should ask how they were attacked. As I’ve said before,

We could safely conclude that the illnesses were due to an attack if attacks were the only thing that made people sick. Since that’s not the case, evidence of an attack would be evidence that rules out all the other reasons that people get sick. No such evidence has ever been presented (at least not to the public).

From that perspective, the new technical report is a neat demonstration, but largely irrelevant to the larger debate. As far as I’m aware, there is still no evidence that embassy personnel were attacked at all, much less with a sonic weapon.