Information regarding the condition of 24 U.S. diplomats working in Cuba that succumbed to what appeared to be a sonic attack earlier this year has been leaked by an anonymous source, offering new insight into the situation, and possibly ruling out the possibility that their injuries were cased by a sonic weapon of some sort. However, the nature of the longer-lasting injuries — namely, damage that was caused to the subjects’ brains — only deepens the mystery regarding the source of the attacks.

This brain damage, common amongst the diplomats and family members that were affected, consisted specifically of damage to the white matter tracts that allow different parts of the brain to communicate with one-another. A growing consensus amongst the investigators appears to be ruling out the use of a sonic weapon to inflict these injuries, as our current understanding of sonic technologies cannot cause damage this specific.

Columbia University biomedical engineering professor, Elisa Konofagou, says that acoustic energy has never been demonstrated to be able to alter the brain’s white matter tracts, and is used frequently in modern medicine.

"I would be very surprised," says Konofagou, of whom isn’t involved in the current investigation, regarding the possibility of a sonic weapon being used in this attack. "We never see white matter tract problems."

The damage to their white matter tracts would also explain why the victims reported encountering the unusual sounds in isolated areas of their residences, environments that should have allowed the sound to carry normally: although the effect of manipulating a broadcast sound to a specific location can be achieved, this is typically accomplished through control of the acoustics of the environment, and would be extremely difficult for a portable apparatus, presumably operating outside of the target’s residence. However, an alteration in brain function could result in the victim falsely perceiving a sound with unusual properties.

Government officials have released a list of overlapping factors in the case, common amongst the patients. According to the Associated Press:

– The most frequently reported sound patients heard was a high-pitched chirp or grating metal. Fewer recalled a low-pitched noise, like a hum.

– Some were asleep and awakened by the sound, even as others sleeping in the same bed or room heard nothing.

– Vibrations sometimes accompanied the sound. Victims told investigators these felt similar to the rapid flutter of air when windows of a car are partially rolled down.

– Those worst off knew right away something was affecting their bodies. Some developed visual symptoms within 24 hours, including trouble focusing on a computer screen.

Thankfully, most of the patients have recovered, with many of them having returned to their duties, although one-quarter are still showing persistent symptoms.

The physicians involved in the investigation have declined to comment on the case for the time being, but their findings are expected to be published in a paper that will be submitted to the Journal of the American Medical Association. However, if the FBI investigation begins to bear fruit on either a suspect or motive — both factors are currently a mystery to investigators — the paper may be withheld, so as not to impede the investigation.