What we hear in 25 is pretty much what we heard at the end of 24. The difference was perspective. I thought about this in two ways.
1) It is just a mood setting thing. Ramping into
Season 3.
2) We all know that this is an audio drama. Sound is critical and ment to be there. In 24 we hear as if we are with
Michael/
Tanya. In 25 we hear it as if we are elsewhere. But where? It is not
Saul and
Victor. We hear them next and the copter sounds is very different.
Angel? Maybe that is what Angel hears. This alerts him that he needs to find a new ride out of Dodge ASAP.
Burt? Not only is he in a different location, he is in a different condition. Hearing is the last thing to go and the first thing to come back. Be it sleep, concussion or drunken haze blackouts.
If it is not mood setting and was entered in someone's Log it is again argues for Burt to have survived.