The sound problem is related to semi-updated Miles and Bink libraries in v1.4 (that is, the versions of those libraries don't like each other, and make problems for many users). I got similar problems (the game crashed when tried to reproduce .bik clips, and also EAX didn't work).
Some guy took working dlls from version 1.3 and placed them in the tech support section of the official forum.
Here's the link:
TheWitcher1.4EE_EAX_fix_TRY3.zip
Just extract them into Witcher/System folder, overwriting the existing files. Tried this, works great.
You can also take these dlls from version 1.3 if you have first, non-EE Witcher. Also update DirectX to the latest november version, just in case.