>The simple explanation is that it is psychosomatic
From the article:
"There are other reasons to think that purely psychosomatic reasons don’t explain what’s happened. For example, the first cases in Cuba were treated confidentially and didn’t appear in the news until six months later. And yet there were several different people suddenly seeing doctors for similar symptoms at almost the same time. Those symptoms came on rather suddenly and were reportedly accompanied by strange sounds. The affected people described those sounds as sharp, disorienting, or oddly focused."
This was happened on a single place among a select group of people (US diplomats and related, in Cuba). They could have talked to each other about the events as they were happening.
I don't know what actually happened and details overall are scarce. The only thing I know is that ruling out psychological effects is difficult to rule out and the kind of argument you quote above has failed in other instances.
From the article:
"There are other reasons to think that purely psychosomatic reasons don’t explain what’s happened. For example, the first cases in Cuba were treated confidentially and didn’t appear in the news until six months later. And yet there were several different people suddenly seeing doctors for similar symptoms at almost the same time. Those symptoms came on rather suddenly and were reportedly accompanied by strange sounds. The affected people described those sounds as sharp, disorienting, or oddly focused."