What psychological horrors people on Titan be dealing with in last hours

The oxygen supply of the missing OceanGate-owned submersible Titan is coming to an end very fast and the fate of the five people onboard including a pilot hangs in balance.

The Titan had oxygen of 96 hours which is believed to have ended triggering an "intense emotional turmoil" among the crew members who are expected to lose their lives if not rescued in the US-French-Canadian-led mission.

The vessel went thousands of feet under the deep sea to take a tour of the Titanic shipwreck which lies in the North Atlantic Ocean.

The operation is in full swing, and remotely operated vehicle (ROV) searches have also been deployed in the area where a Canadian mission detected undersea noises Tuesday.

Doctor Sohom Das, a British forensic psychiatrist told the MailOnline that despite hoping to be rescued, the clock is ticking down, and the "reality is going to seep in."

There are five people on the missing submersible including 58-year-old British billionaire and adventurer Hamish Harding and 48-year-old Pakistani-born businessman Shahzada Dawood, with his 19-year-old son Suleman.

It is also understood that Stockton Rush, founder and chief executive of OceanGate Expeditions is among the crew members with a French explorer Paul-Henri Nargeolet, 77.

"I think they must be in just intense emotional turmoil," Das told MailOnline.

"So at some point, they're going to be quite reflective upon their lives when they're literally staring into the jaws of death and at other points, they're likely to feel extremely panicked, extremely anxious," he added.

"They're going to suffer from physical symptoms from hyperventilation to feeling dizzy to chest pains. They're just going to be overwhelmed emotionally with trying to get to grips with what's happening to them," said Dr Das.

"I imagine that none of them have a claustrophobic disorder. Otherwise, they wouldn't be in that situation in the first place. But nevertheless, I'm sure the intense, claustrophobic nature of the scenario that they're in as they come to grips with the possibility of losing their lives will just add to the overall tension and the feelings of anxiety that they have," he added.

"The sonobuoys detected noise in the water. We don't know the source of that noise,' US Coast Guard Rear Admiral John Mauger told CBS News Wednesday, "with two ROVs and a surface vessel are being used to locate the source of the noise," he added.

"This is an incredibly complex site," Mauger said, noting that "metal and other objects under the water made it difficult to determine the source."

"Aircraft and ships from the US Coast Guard, US Navy and Canadian armed forces searched more than 7,600 square miles of the North Atlantic," US Coast Guard Captain Jamie Frederick said Tuesday.

"Remote undersea equipment was deployed in the area where the sounds were detected and data from the P-3 aircraft was shared with the US Navy experts 'for further analysis which will be considered in future search plans," the US Coast Guard wrote in its Twitter statement.

According to experts, rescuers face major obstacles in saving the people aboard.

Alistair Greig, a marine engineering professor at University College London, said: "It would be difficult to locate the van-sized submersible in the Atlantic without any communication."

The Titan is sealed with bolts due to which the crew cannot even escape without foreign assistance and if it is stuck deep inside the seabed, there would be even bigger challenges because of the huge pressures and total darkness at a depth of more than 2 miles.