plane. renewed reports this morning that a chinese ship searching for missing malaysia flight 370 in the southern indian ocean has picked up a pulse signal. a frequency of 37.5 kilohertz. the same frequency emitted from black boxes. take a listen to what a reporter on the chinese vessel just said. >> this afternoon, the rescuers have heard the ping signal every second. the signals lasted for one minute and and a half. however, the rescuers say this comes a signal of the frequent is not exclusive for the plane black box. there is a possibility that this kind of frequency is from other equipment. at this moment, aviation analyst.