From the BBC -
News that noises have been picked up in the hunt for a missing submersible has offered a glimmer of hope that the five men on board are alive.
Frank Owen, from the Submarine Institute of Australia, says he is confident - based on the information available - the sounds are coming from inside the vessel. "If there was a 30-minute interval, it's very unlikely to be anything but human related," he told the BBC.
Frank says the noises "smack of advice" coming from the fifth man inside - 77-year-old Paul-Henry Nargeolet, a former French navy diver and renowned explorer. "He would know the protocol for trying to alert searching forces… on the hour and the half-hour, you bang like hell for three minutes," Frank added.