Wonderful Engineering

Unidentified Group Attacks US Embassy In Cuba With Mysterious Sound Waves That Cause Extreme Discomfort

Many members of the U.S Embassy in Cuba suffered from a strange kind of attack. Members of the embassy staff claimed to be suffering from symptoms like headache to brain damage and the investigators were unable to identify what was going on. The strange symptoms that appeared in the staff members did not correlate with the presence of any hostile devices in the compound. Doctors assessed that the brains of the victims and the anomalies which were discovered had no clear cause. The repeated sweeps of their hotel rooms also didn’t show any weapons, devices or anything that could be suspicious.

Scientists were unable to think of anything that could have caused this issue. The evidence that was gathered after the incident showed that some sonic or acoustic weapon was used, however, no such weapon exist so far. Many researchers said that acoustic weapons cannot cause such injuries. But, the Associated Press released a recording of the sound that was heard by the victims of the embassy attacks. The sound itself was responsible for the injuries. The sound was not detected or picked up by anyone. But a group of researchers has somehow managed to uncover the mystery.

The researchers from the University of Michigan and Zhejiang University performed reverse engineering on the sound sample and said that the noise causes an effect called intermodulation distortion. This happens when two signals at different frequencies combine to create new signals. They occur at the sums or differences between the two original signals. For example, two signals at 25kHz and 32kHz will combine to produce a signal of 7kHz, which is similar to the one in AP video.

The theory says that the two different devices present in the victim’s rooms produced ultrasonic waves at these frequencies and those signals were combined via intermodulation distortion to produce the noise recorded in the AP video. This explains why some victims hear a noise and others do not hear it as the intermodulation distortion is highly localized. This still doesn’t explain any of the wide variety of symptoms which were experienced by the victims. It is unlikely that the noise itself could have caused the brain damage and symptoms that relate to a concussion in other members of the staff. But it is possible that the device which was producing the ultrasonic waves can somehow trigger these injuries in a different way.

The mystery is still a long way away from getting solved. There is a chance that more analysis can help investigators find the real reason. Till then, we will keep our fingers crossed!