Cuban Sonic "Attack": Researcher Reveals What We Know About Sound Damage

In August 2017, the U.S. State Department announced it was pulling diplomats out of Cuba back in August 2017 over suspected attacks with ultrasonic weapons, which captured the public imagination — as well as that of science reporters, conflict reporters, and sound scientists. We’re still learning about what kind of intentional damage is or is not possible in this sonic weapon scenario, but in the meantime, acoustics researchers are also making sure existing sonic devices aren’t causing unintentional harm. New research, released Wednesday, show some mixed discoveries.

At the 175th annual meeting of the Acoustical Society of America, Southampton University engineer Timothy Leighton, Ph.D., presented evidence suggesting that the brain damage and other health issues experienced by U.S. diplomats was not caused by ultrasonic devices. Less encouragingly, he said that everyday devices could be exposing the general public to unsafe levels of sound. The rules around consumer sonic devices, he said, are outdated and based on unsound science. As more and more sound-based devices come onto the market, including long-range acoustic device (LRAD) Sound Cannons; ultrasonic deer, rat, and mouse deterrents; and even devices meant to shoo teens away, Leighton says that the lack of clear, science-based safety guidelines is a serious public health concern. In his presentation, he outlined the current state of regulation, as well as where it needs to go.

“I looked at all this stuff, and I said, ‘This is an amazing detective story,’” Leighton said in a statement published Wednesday. “I began to pull together a picture that, in fact, the public was being exposed.” In his research, Leighton tracked down the old studies on which America’s current national noise safety guidelines are based. What he found were strangely designed studies that were too underpowered to draw any strong conclusions. But they formed the basis of national policies anyway, and as such, he warns, products on the market have been manufactured and sold according to these flawed guidelines.

Studies involving small numbers of people can fail to show significant trends or correlations and aren’t fit to form the basis for public safety rules. But since this is what happened, Leighton warns that we all may be presently exposed to potentially harmful sounds. That deer repeller at your uncle’s house, the sounds produced by public address systems in public spaces? Nobody knows how safe they really are.

Unfortunately, the way forward isn’t so simple. It’s hard to conduct safety studies on human subjects because it wouldn’t exactly be ethical to blast someone’s ears with loud sound waves to find out how much they can take. Leighton is urging researchers to figure out how to conduct ethical and effective research, as public safety is too important to simply let old, unscientific guidelines rule the day.

“I think 70 years is too long to go with inappropriate guidelines,” said Leighton. “If it’s public exposure, you’re going to have children and newborns exposed as well, and we have no information whatsoever on how safe it is for them.”