I've been having the same issue, but when I try using IndirectSound to fix it, I get the error message that I lack the X3DAudio1_7.dll file needed to run the program. Anyone found a fix for this issue?
Maybe DirectX related? Try updating DirectX: https://www.microsoft.com/en-us/download/details.aspx?id=35&
Copy & paste the url. GoG's url tags apparently break at &.
I also have problem with that file missing. I got DirextX 12, should be the latest as far as I know.
I wrote the the guy on IndirectSound about C3, maybe he has time to look at it.
But as I read here it seem to work for some people.
What Windows and DirextX do you have ?