I've been able to confirm the sound problem people are complaining about, but I still don't understand why people are blaming the turn sound.
There's a mixing artifact of some sort, and I'm pretty sure it's in the engine sound mixing, but it could be the underlying mixing that sdl does with everything. I have to look deeper into it, by first disabling the engine sound, and then enabling only the engine sound, so I guess that means that the first thing I need to do is add the configuration items for disabling/enabling all the sounds and music.
I'll see what I can do. My plate is actually pretty empty right now, and I've decided my future requires me to gain some more recent open source credits (amongst other things), so consider me activated for now. But don't expect miracles, I'm way out of practice in both C++ and arma's codebase.