Im getting the dialog and the music but most of the game sounds arent working. Sometimes i hear sword noises but a lot of the time theyre silent. I also couldnt hear the roaring at the cave.

Anyone have a fix please?

I'm having exactly the same problem.

As I am playing Silver atm I've just stumbled upon the same problem. The only way I found, to get those missing sound effects (like opening doors, swinging swords etc), was turing "compatibility mode". Problem is, though it brought back all sound effects, it also broke the quality of dialogs and music which is very similiar to the problem from that thread:
http://www.gog.com/en/forum/silver/stuttering_sound