Angus Houston, head of the Australian agency coordinating the search for missing Malaysian Airlines Flight MH370, speaks during a news conference in Perth April 7, 2014. Reuters

Australian authorities said Wednesday that search equipment scouring the southern Indian Ocean for signs of the missing Malaysia Airlines Flight MH370 had detected two new signals that might be from the lost plane's flight data recorders, and that sonar buoys would now be deployed in the area.

The two “pings,” which were picked up by the equipment on Tuesday, were heard for more than 12 minutes and have helped authorities significantly narrow the search area and to determine if they are closing in on the “final resting place of Flight 370,” Angus Houston, a retired senior officer of the Royal Australian Air Force who is leading the search, told reporters at a briefing in Perth. Sonar buoys are equipped to emit radio signals when they detect sounds underwater.

“What we're picking up is a great lead,” NBC News quoted Houston as saying. The new signals could help data specialists to choose “a much more sharply defined search area — a much smaller search area underwater.”

The search area has now been reduced to approximately 46,800 square miles, which is about a third in size of the area searched during the initial days of the international operation, which has involved more than two dozen countries and cost millions of dollars so far.

The latest finding is a significant development in the massive search effort as the plane’s “pingers” were expected to die out given that their battery life is only 30 days, and the plane has been missing for more than that period. However, according to Houston, there may still be some time left before the batteries die out permanently. Flight MH370 disappeared on March 8, on a flight from Kuala Lumpur to Beijing, with 239 people on board.

According to Houston, the ocean floor in the vicinity of the current search area is very silty, making it difficult for search officials to detect signals. However, Houston did not make a concrete statement on whether the officials had come closer to locating the plane “without visual confirmation,” NBC News reported.

“It's nothing natural -- it comes from a manmade device, and it's consistent with the locator on a black box,” Houston said. “But we've got to lay eyes on it.”