I am still waiting for a fix to this myself, or at least a reply to my post which is almost 100% Identical

Have you tried disabling every "advanced" sound option (3D sound, EAX etc)?

These are known to not work on Vista and later due to changes in Windows audio subsystem. Thus, try running it in "software sound" and in 2.0 stereo configuration just to see what happens.

Try this: https://www.gog.com/forum/neverwinter_nights_series/help_with_nwn2_sound_problems/post4.

I went to "C:\Program Files (x86)\GOG Galaxy\Games" and moved the NWN2 complete folder to the desktop, all files and sub folders were moved along with it. I opened the folder on my desktop and launched the game like normal....no sound issues, the sound worked perfectly fine. This might be considered a fix, however i would like to know why it only works from desktop, and how to have the same effect without having to move the NWN 2 game entirely to desktop

As we see, strange things can happen. :)

Maybe it has something to do with file privileges. Desktop is under C:\Users\YourUserName\Desktop so programs launched by you have full read/write access to all files and DLLs. Program Files is a protected operating system folder and you have to run programs as administrator to avoid issues.

As a rule of thumb, since Windows 7 you should avoid installing games under Program Files, it's best to have separate folder outside, and even better if it's on a different disk (i.e. D:\GoG, D:\Steam etc).

I just had this on my Win 10 Pro x64 system recently. A totally mute NWN 2.

I installed the latest version from GOG galaxy to no joy and then tried several different fixes listed on the forums which also failed. I then downloaded the backup copy and did a manual install as admin which worked fine until I restarted and the mute issue returned.

The only way I resolved this was to install an older manual installer version (2.1.0.6) that I had saved a couple of years ago. It's still working fine now. I wonder if there maybe something screwy with the latest version of the installer.