The loud airplane engines are a bother, but if you turn other engines down you can still hear their track clearly. Does not help if they are sitting at idle, but you can, at least hear them move.
It seams there is still a lot of room for improvement in the sound part of this game period. It is kind if hard to tell direction also and the delay of the explosions also seem a bit lone.
Over all, though, when done, I think this game will be pretty sweet.