I've red on dev forum that there are plans for 3d audio, maybe with OpenAL implementation. If so, you can look at my c++ OpenAL wrapper at Auio3D. Feel free to use & modify it, if only find it useful in some way. There is no license.
It was originally developed for Celestia, that's why there are its name in macros.
I have not seen any developed expressing interest in 3D audio.
That means, best way to get in into the game is to contribute code.
Then we could debate how "real" it is with sound in space, but at least in atmosphere it might make sense.
Found this 3D audio lib built ontop of SDL_Mixer (5 years ago): https://github.com/NotAPenguin0/audeo