Download the "OSX/Linux" version, which doesn't use the installer.
Open the shs_soundsets_osx.zip file with your favorite archive manager and go through shs#soundsets\soundsets\.
Open each folder you want the sound files for, and extract them to your BG2 - SoA\sounds folder.
Download the attached file, and extract it to your sounds folder as well.
Run oggtobg.bat from inside your sounds folder (it will convert all your ogg files into the right format, then delete the old ogg file).
That should be all you need. I tested it briefly with the first sound set on a clean BG2 backup I have. First sound played, and that was the extent of my testing.
If it works, awesome. If not... well, I'm sure someone else can help you better than I.
thxx a lot, it should probably work, because I managed to make the files ready to BG, and the test without BG (playing with a mediaplayer) was a complete success. The final result (work with BGII/tutu or not) will come tomorrow