Audio of the noises detected during the search for the Titan submersible that prompted hope of the crew’s survival has been released as part of a new documentary.

The bangs were recorded by sonar buoys in a massive rescue operation for the missing submersible and its five passengers.

It was lost on a deep-sea voyage to the Titanic wreck in June 2023 and later found to have imploded killing all on board.

U.S. Navy analysis determined that the banging noises were most likely either ocean noise or noise from other search ships, an official told the BBC’s US partner CBS.

The Royal Canadian Air Force team that led the search and rescue mission gave the audio to producers of The Titan Sub Disaster: Minute by Minute, which is due to air on Channel 5 on 6 and 7 March.