Redownloaded the game today and I get the audio issue immediately. It used to work fine before, but now on the x64 client there's no audio from the very beginning - even the intro videos are silent. On x32 there's audio just fine, but it crashes due to being out of memory anytime I try to load into any map (got a paging file over 10 GB in size, checked to be sure based on previous comments). Tried windows vista compatibility, reinstalled directx libraries linked in another thread, experimented with the engine.ini audio pool - nothing works, the x64 executable just refuses to play sound. Kinda makes the whole thing unplayable, which is a shame.
Windows 10 here.