SAN DIEGO (October 22, 2012)--In a study published online Monday in Current Biology, researchers at the National Marine Mammal Foundation in San Diego say they recorded the spontaneous sounds of a captive male Beluga whale, while underwater and when he surfaced.

The whale song sounded so eerily human that divers initially mistook it for a human voice.

Scientists think the whale's close proximity to people allowed him to listen to and mimic human speech.

After several years, the whale went back to sounding like a whale, emitting high-pitched noises.

The whale died several years ago.