screaming in the plane itself. >> the cockpit is a very very noisy place. so that sound of the people screaming and the banging on the door had to be really high decibel level to overcome that. we generally have to use enhancement techniques just to get through that noise to hear anything anything. they were at a very high level. >> also audio investigators will listen to the alarms going off, the warnings going off. that also paints part of the picture of what is happening in the cockpit. >> yes, it does. in fact the cockpit area microphone and channel are designed to pass more frequencies than just human frequencies because they need to be able to detect after the fact whether or not there were any alerts warnings hail hitting the windshield any number of