Angus Houston, the head of a joint agency coordinating the search in the southern Indian Ocean, calls it "very encouraging." But he said Monday that it may take days to confirm whether signals picked up by the ship Ocean Shield are indeed from the flight recorders on Flight 370.

He says the position of the noise needs to be further refined, and then an underwater autonomous vehicle can be sent in to investigate.

The plane vanished March 8 during a flight from Kuala Lumpur, Malaysia, to Beijing.

The Malaysian authorities are investigating a myriad of theories of how the plane disappeared and have not ruled out a possible terrorist attack.

According to the BBC, Houston said the sounds were the "most promising lead" so far, but added, "We haven't found the aircraft yet and we need further confirmation."

SHI/SHI