The idea appears to have been based on a recording that is currently being analyzed by the US Navy’s cutting-edge acoustic detection and processing hardware. It’s been reported that the signal is made up of at least 20 different frequencies, which suggests a single species of critter isn’t making them.
The Cuban panel has assessed the very same audio recording, and has decided that crickets, and possible cicadas, are responsible for the noise.
Let’s take a look at the details of the attacks, which have been happening as late as August. They occur in a range of locations – normally state-owned buildings, which includes residences foreign envoys live in – and times of day. Some of them include high-pitched noises, some don’t, and for the most part, people sleeping or standing right next to the victims don’t hear a thing.
Although the “sonic weapon” hypotheses are beginning to look a little shaky as of late, framing crickets as a possible antagonist isn’t exactly a solid idea either. Nothing adequately explains all of the symptoms.
So far, Cuban experts haven’t linked the noise to brain damage, which there's no solid evidence for whatsoever. Still, they have suggested that the insects could be noisy enough to induce hearing loss, irritation, and blood pressure spikes, per Quartz. It's not clear how likely this is either.
Regardless, the idea that all these diplomats, all of which are geographically and temporally segregated, are falling victim to these curious symptoms at the very same time that crickets are sneaking up on them and chirping in their ears – and only their ears – seems a little, well, off.
Stanley Fahn, the H. Houston Merritt Professor of Neurology at Columbia University, has seen the Cuban report’s summary – but not the details of it. He told IFLScience that “it would seem strange that cricket sounds could cause brain damage to humans, let alone other animal species.”
Although Fahn still suspects that stress is a possible cause, he’s “curious to see the actual report of the MRI changes in the brain, and if they are uniform in all the afflicted individuals, and how they differ for non-afflicted individuals.”
For what it's worth, the US state department has yet to place the blame explicitly on Cuban authorities, and psychogenic illnesses aren't exclusively linked to sketchy-sounding theories. Stress is known to do some odd things to the brain, and there's a lot we don't yet understand. Some US scientists have expressed similar psychosomatic conclusions based on media reports. Saying that, a healthy dose of skepticism is essential here.