I'm posting this because I have not found a fix in the forums regarding this issue other than the unofficial patch.

I had a problem where the sound was messed up: chipmunks, looping over and over, stuttering, etc.
What fixed it for me is to simply specify your sound driver then disable 3D Sound Buffers and EAX:

1. Right click your The Suffering shortcut (the one created by installer) then click properties.
Note: If you have none, go to The Suffering directory and create shortcut for SUFFERING.EXE
2. Add -setup at the end of target (see screenshot)
3. Click OK.
4. Run the shortcut.
5. The setup will show up, go to Sound tab.
6. Instead of Primary Sound Driver, specify your sound driver (see screenshot).
7. Uncheck "Use 3D Sound Buffers" and "Enable EAX (Environmental Audio)". (see screenshot)
8. Click OK.

Tx helped me nowadays!

Thank you! This solved my issues! For the record, all you need to do is uncheck the 3D sound buffers and it fixes the problem.