The United States State Department has spent two years investigating “sonic attacks” in Cuba that allegedly gave American diplomats a range of worrisome health symptoms, including tinnitus, vertigo, and cognitive impairment. Initially, investigators blamed covert sonic weapons, but a similar incident that occurred in China in May cast doubt on the sonic device explanation entirely. Now, a new report suggests an even stranger source of the sounds.
In a preprint paper uploaded to bioRxiv on January 4, a pair of researchers show that a diplomat’s recording of the alleged sonic attack, released to the Associated Press in October 2017, was actually just the sound of a cricket doing a mating call.
The authors came to this conclusion by comparing a handful of acoustic signatures in the recording to their corresponding features in the mating call of the Indies short-tailed cricket. Authors Alexander Stubbs, a graduate student at the University of California, Berkeley, and Fernando Montealegre-Z, Ph.D., a professor of sensory biology at the University of Lincoln in the United Kingdom, write: “the calling song of the Indies short-tailed cricket (Anurogryllus celerinictus) matches, in nuanced detail, the AP recording in duration, pulse repetition rate, power spectrum, pulse rate stability, and oscillations per pulse.”
Stubbs and Montealegre-Z’s proposal calls into question the “sounds” the diplomats claimed to hear, but it doesn’t dispute the fact that the diplomats experienced real harm. In a March 2018 JAMA study of 21 people from the embassy who reported inexplicable exposure to auditory or sensory phenomena, doctors confirmed that most individuals experienced persistent symptoms, though they couldn’t identify the source of the trauma.
Investigators haven’t yet ruled out microwave devices, ultrasonic weapons, biological agents, or mass hysteria, but whatever the cause, the paper argues that the symptoms weren’t caused by the sound circulated by the media.
“This provides strong evidence that an echoing cricket call, rather than a sonic attack or other technological device, is responsible for the sound in the released recording,” the team writes. “The 7 kHz buzzing sound recorded by U.S. embassy personnel and released by the AP is entirely consistent with an echoing insect source, and not likely to have resulted from a ‘sonic attack,’” they continue.
“This supports the conclusion that the AP recording arises from echoes of a natural source.” Even if proven true, however, it may be too late to do damage control. As a result of the alleged sonic attacks last year, the US expelled 15 Cuban diplomats from Washington, D.C., and brought most staff home from the US embassy in Cuba.