deployed from the australian defense vessel, "ocean shield," has detected signals consistent with those emitted by aircraft black boxes. two separate signal detections have occurred within the northern part of the defined search area. the first detection was held for approximately 2 hours and 20 minutes. the ship then lost contact before conducting a turn and attempting to reacquire the signal. the second detection on the return leg was held for approximately 13 minutes. >> reporter: houston went on to say that these signals are consistent with the characteristics of an inflight data recorder and a cockpit voice recorder. so, incredibly promising development, but at the same time, they're urging caution. all of this still needs to be