right now a british navy survey ship in the area of the indian ocean where a chinese ship detected underwater signals. this could be a lead for flight 370. there's serious concern about the equipment that detected the pulses. here is cnn's report. >> reporter: we now know more about the equipment used when the pinging sound was reportedly detected. we spoke to the company that makes it. they tell us divers can use it or it can be used hand-held from the surface like the chinese are doing in this video. clearly this hydrophone does not go as deep as the tow pinger. remember, the tow pinger is what crews are using on board australia ship "ocean shield."