Australian marine researchers shared a recording recently of a deep sea microphone that reveals an unusual underwater sound on the day Malaysia Airlines flight 370 disappeared though they acknowledged a link is far-fetched.

"I think it's something that they [the Joint Agency Coordination Center in charge of the search] need to include in the mix," Alec Duncan, a researcher at Curtin University in Australia, said today.

With the search for the plane moved to the Indian Ocean, researchers at Curtin went back and looked at the data from their microphones, which they use to listen for earthquakes or nuclear testing.

After listening to the microphones' recorders, the scientists said Tuesday they'd found that on March 8, the day the plane - carrying 239 people and en route from Kuala Lumpur to Beijing - went off radar, there was a sound in the South Indian Ocean.

The sound, however, was thousands of miles from the current search area, Duncan said. The researchers though have continued their investigation.

"I'd like to think it's something related to the aircraft," Duncan said, "but I think it's more likely that it is a small underwater seismic event, so small, like an earth tremor type thing."

Even the scientists say it doesn't add up because the jetliner was pinging a satellite every hour. The sound was recorded more than an hour and 11 minutes after the last satellite transmission from the aircraft. And the sound's location is far from the projected flight path those pings suggest.

Still the researchers felt it was necessary to share the information.

"I'd love to be able to sit here and say, 'Yeah, we've found this thing and it's from the plane' - but the reality is, there's a lot of things that make noise in the ocean," Duncan said.