Good for you, but in case someone else wonders in.
To use soundpack you can either use launcher(windows) to download it or download them yourself.
If you used the laucher it will auto place the soundpack in the necessary folder so you need to go to the game > settings > options and right at the bottom there should be “Choose soundpack= Basic” (by default), you need to select the soundpack wich you downloaded and then restart the game.
Now if you dont use launcher or the soundpack inst covered in the laucher (Mine for example…gratuitous self ad is gratuitous).
Download the pac, go to cdda folder > data > sound and just drop the soundpack(unzipped) in there. Then you need to go to the game > settings > options and right at the bottom there should be “Choose soundpack= Basic” (by default), you need to select the soundpack wich you downloaded and then restart the game.