For modern OS like Windows 7, 8 and 10.
The first patch is to have Surround sound 7.1 working, which is only available when using EAX as sound provider in the audio settings:
-Download IndirectSound and extract the files to /path-to-your-game.
-Open dsound.ini and change eax1 = false to eax1 = true.
-Start the game and set the sound provider in the audio settings to "Creative Labs EAX ™", choose your speaker configuration and click "Save" to confirm the changes.
The second patch is to sort the missing some audio issues, like radio commands and vehicle music on all Windows OS since Windows Vista. The fix below consist of lying about the windows version:
Install compatibility profile
-Download and install the compatibility profile.(upload soon)
-Remove any compatibility mode setting on the games executable.