not just necessarily one, since both flight recorders are equipped with pingers? they re both both recorders are equipped with a unique pinger but the pinger is on the same frequency, so the 37.5 kilohertz is identical to both pingers. if you hear one and the other one is adjacent or nearby, you re going to hear a second ping. it won t be synchronized. the units don t talk to each other, so you will hear two independent pings at that same frequency and same pulse rate. and according to the reporting, the chinese are saying the sound they heard was not continuous but lasted maybe for about a minute and a half. is that a viable description of how a pinger just might work? does that sound, you know, like a pinger with perhaps a dying battery? well, it s hard to say. we ve not duplicated a situation like that in the lab where it would stay on and then turn off and then stay on. typically it s continuous, and