is talking and you're better at explaining it. >> well, we've got the pinger to try to locate the most valuable piece of evidence that we have with the most information. both the cockpit voice recorder and the data recorder. as far as the voice recorder, we can certainly determine who is speaking because there are four discreet channels. one for the pilot, one for the co-pilot, one for the cockpit area microphone which picks up all of the sounds within the cockpit. whether they're human voices or engine sounds, alerts, alarms, anything that can be heard in the cockpit. and the fourth one is generally the intercom system. >> you said through all of that you can tell if the plane is operating properly, normally and he'll tell us how he can distinguish that by using sound coming up right after this break. ap me in a rate. that's correct.