In the fall of 2016, American diplomats in Cuba complained of high-pitched sounds that were leading to headaches, vertigo, and hearing loss. A recording, made by diplomats and circulated by the Associated Press, fueled speculation about a sonic attack by adversaries of the United States. But two scientists, Alexander Stubbs of the University of California, Berkeley, and Fernando Montealegre-Z of the University of Lincoln in England, now say the evidence points to a more benign source: crickets. They’re quick to say they can’t rule out an attack altogether. But the sound they examined doesn’t match up with that hypothesis. “All I can say fairly definitively is that the A.P.-released recording is of a cricket,” Stubbs told The New York Times, “and we think we know what species it is.” That would be the Indies short-tailed cricket (or a close relative), known for making an enormous racket.