By Tyler Vosgerchian
March 16, 2018

Ann Arbor, Mich. — Professors Kevin Fu of the University of Michigan and Wenyuan Xu of Zhejiang University have published a paper, “On Cuba, Diplomats, Ultrasound and Intermodulation Distortion,” which suggests yet another alternative explanation for mysterious symptoms suffered by diplomats stationed in Havana, Cuba.

So far the symptoms of mild hearing loss and neurological damage, which reportedly affected 21 U.S. and eight Canadian diplomats from November 2016 through February 2017, have gone unexplained. Previous theories range from mass hysteria to swarms of cicadas to claims of an unknown type of sonic cannon. This new study adds to this list by suggesting the symptoms could be caused by malfunctioning ultrasonic equipment.

The Trump administration has used this incident as a pretext to expel dozens of Cuban diplomats from Washington and issue unfounded travel warnings to discourage travel to Cuba. Cuba is well-known as a safe travel destination, so it is important to get to the bottom of this issue.

The FBI, the CIA and the Cuban government have all conducted independent investigations. The U.S. agencies have refused Cuba’s offers of medical and investigative cooperation. A deputy of Cuba’s Diplomatic Security Division reports that the U.S. State Department “prevented the investigators access to the events, which they reported months, days or hours later, and to victims and witnesses” or even complete medical reports.

The Cuban investigation is documented in a 30-minute youtube with English subtitles: tinyurl.com/ybl7ulgd.

Cuban doctors visited the homes of hundreds of people who lived and worked around the diplomatic community and the hotels. None of these people reported any symptoms. This discredits the idea of a traditional sonic cannon, such as the type used by New York City police for crowd control, which would have been noticed by anybody in the area.

It’s telling that at the conclusion of its investigation, the FBI discounted the sonic cannon theory while the CIA still holds onto it. According to an Oct. 2 Associated Press report, CIA agents stationed in Havana under diplomatic cover put out the first reports of suspicious sounds and experienced the most serious symptoms.

The U.S. diplomats have made a recording of the mysterious noise they claim caused them their symptoms. They reported hearing these noises at home and at a hotel. The noise on the recording is less than 90 decibels, the level that would produce hearing damage. The new theory is that the symptoms weren’t caused by the volume of the noise but by the frequency.

Ultrasound is any sound whose frequency is too high for the human ear to hear, that is, higher than 20 kilohertz. Ultrasonic technology has many applications in modern technology, including occupancy sensors and some types of wireless communication present in most modern office buildings.

The UofM scientists theorize that the interference between two or more of these ultrasonic devices could have caused an audible byproduct through a process called intermodulation distortion. They tested this theory in the laboratory and were able to produce an audible noise from two inaudible ultrasonic devices. This noise was similar to that on the recording.

This theory is much more plausible than that of the sonic cannons or the swarms of cicadas. Alongside the occupancy sensors the paper suggests that wireless eavesdropping devices may have produced some of these ultrasonic frequencies. While this type of high-tech espionage isn’t unheard of in the diplomatic world, neither the Cuban investigators nor the FBI have found any such devices.

If something like these devices were found, it’s likely we would hear about it from the bombastic Trump administration, which is grasping at straws at this point trying to find any excuse to sabotage the improvements in U.S.-Cuba relations that the Obama administration promised. On March 2 the State Department made permanent the staffing reductions at its embassy in Havana. This seriously curtails its ability to issue both immigrant and non-immigrant U.S. visas to Cubans.

As Cuba has emphatically stated, it has never attacked nor allowed any attacks on the U.S. or other diplomatic delegations. On the contrary, for over 59 years Cuba has been the target of U.S. military and biological attacks and an ongoing economic, financial and commercial blockade.

Though Canadian diplomats also noted sounds and illness, their government has not withdrawn staff at the Canadian Embassy in Havana nor has it reduced the staffing it allows at the Cuban Embassy in Ottawa.