The sound of the doomed airliner going down in the Indian Ocean may have been recorded by a directional microphone system. via Unexplained-Mysteries: Exactly what happened to Malaysia Airlines Flight 370 after it took off from Kuala Lumpur International Airport on March 8, 2014 still remains one of the most enduring mysteries in aviation history. Now though, almost five years on, researchers believe that they may have found a new clue in the form of audio recordings from around the time MH370 is thought to have crashed in to the sea. The four distinct sound events, which were caused by low-frequency acoustic-gravity waves, were picked up by hydrophones designed to detect evidence of illegal underwater nuclear testing. While one of the events occurred relatively close to where MH370 is thought to have gone down, two of the others seemed to be thousands of miles away from where the search teams had been looking. Researchers at the University of Cardiff in Wales and the Memorial