By: Robin Andrews/IFL Science Something’s afoot in Havana. Over the last 24 hours, reports are coming down the grapevine claiming that five US diplomats and at least one Canadian envoy have fallen ill, all suffering from acute hearing loss, headaches, and nausea. The cause? A covert sonic device – an acoustic weapon – that’s being used to terrorize the diplomatic staff.
The details around the incidents, which have been taking place in Cuba since autumn of last year, are hazy. US authorities have said that they do not have the permission to speak publically about what’s happening, but the Associated Press explains that the symptoms of the mystery illness have in some cases been severe enough that the diplomats have had to return to the US to recover.
Months of investigation revealed several facts about the onset of the symptoms. They always appeared suddenly, not gradually, and only took place inside Cuban government-owned properties – normally the residences of the diplomats themselves.
The specificity of the targets, and the hearing loss associated with the illness has led both the FBI and the Diplomatic Security Service to conclude that a powerful acoustic device was the trigger.
Cuba’s state-run security and surveillance services spend much of their time tracking American envoys through the island nation. US investigators suspect that they could be to blame, but a third party, acting with or without the knowledge of the Cuban government, could also be the culprit – Russia, for example.
An ongoing investigation has resulted in the apparent expulsion of two Cuban diplomats from their embassy in Washington DC back in May of this year.
So what exactly is an acoustic weapon? There’s been no documented use of such a device for the purposes of attacking diplomatic personnel, so if the American investigators are right, then this would be the very first deployment of one.
Sound can clearly be used as a deterrent. After all, if something is loud enough, it causes physical damage to the inner workings of someone’s ear. As pointed out by Salon, “guns” that fire narrow beams of deafening sound do exist, and they have been used by vessels in the US Navy and even by city authorities seeking to ward off certain protestors.
The curious thing about these incidents in Havana, though, is that the suspected sonic devices haven’t been accompanied by audible noises. They appear to be operating at a frequency beyond that of human hearing, and yet they’ve reportedly caused hearing loss and headaches in the targets.
There are two ways in which this could be achieved. The first would be to use microwaves. Imperceptible to people lacking detection technology, it has been shown that small beams directed at people’s heads rapidly heat tissue within the brain, generating a small shockwave.
This shockwave is registered as sound by the ears, which then vibrate at an extremely high frequency. All in all, hearing loss and severe headaches are inevitable. Worryingly, such a device would also cause lasting neural damage if the microwaves were energetic enough.
Infrasound – sound that is at a lower frequency than the range that’s picked up by human hearing – can also cause hearing loss in some cases. According to the US National Institutes of Health, being exposed to concentrated infrasound can cause “fatigue, apathy, and depression, the pressure in the ears, loss of concentration, drowsiness, and vibration of internal organs.”
At this stage, it’s deeply unclear which is more plausible – but the point is that “silent” acoustic weapons do exist, and they certainly could have been deployed in Havana.