that would be a very key bit of information for the investigation. >> miles, john brings up a great point. when you listen to the cockpit voice recorder when you pull this audio, you are not going to get a running narration from the pilots probably but there are a lot of other things that you can listen for that are informative. >> yeah. there have been cases, there's an accident we are familiar with where one of the windshields blew out in an aircraft which could clearly cause a decompression event, rapid decompression event. some sort of incapacitation or partial incapacitation of the crew. and certainly, that kind of noise along with the associated warning signs and along with did somebody have a mask on are they breathing as if they are breathing through a regulator or respirator. all those things will be captured by the cockpit voice recorder. it's good that they have that data and good they are analyzing it and that will do an awful lot toward shedding light on