Houston has expressed optimism about the sounds detected earlier in the week, saying on Wednesday that he was hopeful crews would find the aircraft—or what's left of it—in the “not-too-distant future.”
The locator beacons on the black boxes holding the flight data and cockpit voice recorders have a battery life of about a month, and Tuesday marked one month since Flight 370 disappeared.
The plane veered off-course for an unknown reason, so the data on the black boxes are essential to finding the plane and solving the mystery.
Investigators suspect it went down in the southern Indian Ocean based on a flight path calculated from its contacts with a communications satellite and analysis of its speed and when it would have run out of fuel.