I think I have read somewhere that it is impossible within Prepar3d to separate the audio into different channels. The best you can do is to separate the voice audio from everything else on its own channel. The problem with this is that the VOR Ident sound still comes in through the primary playback device and is mixed with the engine noise and stuff. Basically means that you cannot separate the outside noise from headphone noise. Is there any solution for this other than playing engine/outside noise with custom software?