Hopes that wreckage of the missing Malaysian flight MH370 will soon be found were fueled again, as a possible fifth signal was detected, Australian officials said on Thursday.

While it conducted an acoustic search on Thursday afternoon, a Royal Australian Air Force aircraft has detected a possible signal in the vicinity of the Australian Ocean Shield, which detected four signals on Saturday and Tuesday, Chief Coordinator of the Joint Agency Coordination Center (JACC) Angus Houston confirmed.

"The acoustic data will require further analysis overnight but shows potential of being from a man-made source," Houston said.

The underwater search also continued Thursday, with the Ocean Shield at the northern end of the defined search area, and Chinese ship Haixun 01 and HMS Echo at the southern end.

The pilot of the missing Malaysian passenger jet MH370, Zaharie Ahmad Shah, was the last to speak to air traffic controllers, CNN reported Thursday, citing Malaysian sources. The sources also told CNN that there was nothing unusual about his voice.