Does Cuba really have 'sonic weapons'?

News of a secret sonic weapon used to attack US diplomats in Cuba has left scientists baffled and unable to come up with an explanation.

The US embassy building (right) in the capital Havana. Photo: AFP

Citing medical documents, the US CBS news channel reported that a number of American and Canadian diplomats working in Cuba were diagnosed with central nervous system injuries by doctors. It is assumed that they were attacked with some kind of sonic weapon.

US State Department spokeswoman Heather Nauert refused to confirm CBS's report at a press conference on August 24, but she acknowledged that at least 16 diplomats had suffered from strange symptoms and were being treated in the US and Cuba.

The veil of secrecy

Other reports suggest that the FBI and the Royal Canadian Mounted Police conducted an investigation in Cuba and concluded that some type of sonic weapon was used, but no one has any concrete answers.

In addition to questions like who the perpetrator is and what the motive is, the technology of the sonic weapon raises many questions.

Such weapons do indeed exist, but they mainly emit loud, audible sounds. According to initial information from Havana, the mysterious weapon emits sounds that cannot be heard by the human ear.

“The story is really mysterious. I don’t know of any sound effects that cause concussion-like symptoms. According to my research, to have a strong impact on humans, it requires a very high sound intensity, which can be heard when emitted,” - Professor Jürgen Altmann, a physicist at the Technical University of Dortmund (Germany), commented on the information reported by the media.

According to Dr. Charles Liberman of Harvard Medical School, to cause sound-induced hearing loss, the part that perceives sound (hears) must be overloaded.

Both experts Altmann and Liberman noted that due to the lack of data, it is difficult to explain what type of device was used.

“High-intensity sound at any frequency can cause harmful psychological effects or behavioral changes in humans,” added Scott Masten, a toxicologist at the National Institute of Environmental Health Sciences. “We are not aware of any studies on the health effects of sound when it is used intentionally to cause harm.”

Illustration of a sonic weapon. Photo: iflscience

A myriad of assumptions

In the latest developments, the Cuban government asserted that it had nothing to do with what happened and the US State Department has not yet determined the origin of the attacks.

“We are not assigning blame at this time, we do not know who the perpetrator is. The investigation is still ongoing,” said US spokesperson Nauert.

According to the US Fox News station, there is a hypothesis that the device used to attack the diplomats emitted infrasonic waves - a type of sound with a frequency lower than 20 Hz, below the threshold of human hearing.

A study published last year by the University of Portsmouth (UK) described infrasound waves as having the potential to be used for military purposes, paralyzing targets on the battlefield.

Additionally, the device's ability to emit ultrasonic waves is also mentioned. These are sound waves with frequencies above 20 KHz, also beyond the range of human hearing.

“It is possible to assume that ultrasound waves were used, but to send these waves over long distances and through walls is not an easy task,” commented Dr. Altmann.

One possible explanation for the diplomats' symptoms, according to Mr. Altmann, is the use of certain chemicals that cause hearing loss.

This group of chemicals, which includes some industrial chemicals, can damage the inner ear and auditory nerve.

Most scientists, including Mr. Altmann, are unaware of any such “sonic weapons” in reality.

“The closest thing is an LRAD – a device that emits a loud, audible sound,” explains Altmann.

Long-range acoustic devices (LRADs) have been used by police forces in several countries as a type of “sound cannon.” LRADs were used to disperse crowds protesting against the G20 summit in Pittsburgh, USA, in 2009.

A federal judge in June ruled in favor of a lawsuit filed by six people against the New York Police Department over LRADs, who complained of migraines and hearing loss after police fired “sound cannons” during a protest in 2014.

According to TTO