Hmm sounds like the install might be set to general midi... You should launch the game into the installer and reset the sound to soundblaster 16 or something like that. (adding a ' -i ' after WC3 should send it into the installer)
I found the solution obviously the the config file created by gog is so messed up, that I had to delete it and setup new soundcards for music and sound fx in the setup. there I also had the chance to calibrate the "ultrasensitive" joystick. I also changed some cpu cycles, so that the game runs smoother.