The mysterious noise that injured several U.S. diplomats and intelligence officials has finally been discovered.
The Associated Press obtained a sample of the high-pitched, cricket-like sound which is believed to be the culprit. It's lengths and pitches vary, and includes a combination of frequencies, some of which are beyond human hearing. While the obtained recordings vary, several people who have heard the sound confirmed the recordings were similar to what they heard in Cuba.
Recordings of the sound were analyzed by the U.S. Navy, but many of the details behind its origin remains a mystery.
What is clear is that at least 22 U.S. officials working in or with the Cuba embassy were injured, and that many were U.S. intelligence officials. Injuries sustained included hearing loss and brain damage, some of which has not healed.
The attacks are believed to have started last year, around the same time as the election. They have been ongoing ever since, with the most recent case occurring reported in late August.
Cuba has denied any involvement in the attacks. Meanwhile, the government is now training U.S. embassy workers in Cuba on what to listen for going forward.
The Associated Press contributed to this story.