How to change the sounds of the game
In this tutorial we'll change the main menu music with the song of Nightwish "Nemo". Changing the games music is really simple.
With the following method you can change:
1.Sound.pak files       (items sounds)
2.Music.pak files        (backround music)
3.SpeechEnglish.pak (english dialogs)
Step 1  : Download G3Pak, a "ogg" file converter-like this one and media player ogg codec so that you can hear the ogg files
Step 2  : Run the G3Pak program go "file>open-GothicIII>Data>Music.pak"
Step 3  : Press "extract dir"
Step 4  : A new folder "music" will be created in game's data directory
Step 5  : Open the folder. As you can see there are two folders in it. Open "fragments"
Step 6  : Here you can find every "backround" music file of the game. We want to change the main menu file so open the "myrtana_title_day_01.ogg". Right click>open with>media player and check the "open always those files with this program". Hear it to check that it is the right song.
Step 7 
: Now it's simple. You have to find the song you want to replace this ogg file. I found "Nemo" in my music folder. Now you have to convert it!:
IF YOU HAVE DOWNLOADED THE PROGRAM I TOLD YOU:
Step 8 
: Open it. Click "Evaluate" and then click mp3 to ogg (or whatever your file is to ogg)
Step 9 
: Click "add" , find your song and double-click it so that you'll go back to main window and your song will be there.
Step 10
: Click "convert". It'll convert the mp3 to ogg. You can find the ogg file in the place you have choose to extract the files in the installation.
Step 11
: Now that you have the file you just have to rename it to myrtana_title_day_01.ogg and copy-paste it to the GothicIII>Data>Music>fragments folder!. That's it replace the texture and run the game!
Here it's a video where you can see what we did in this tutorial in combination with the gui tutorial. Isn't it nice?
VIDEO
Hint: If you want to disable, stop and delete the  the sound of a file PB has a nosound.ogg in Sound directory. Just copy the file nosound.ogg to the folder where the other ogg is (the one you want to stop the sound). Then rename the nosound.ogg and write the ogg's ,you want to stop, name.