You could do it in a fairly simple 2-step process with
DVD Decrypter and
Super.
Open DVD Decrypter and choose your dvd location. Then under "mode" chose "ifo". Then go to tools/settings and chose the "ifo mode" tab. Go to where it says "file splitting" and chose "by chapter". Click ok. Now in the main window go to where it says "stream processing" in the upper right hand corner. Coose "enable stream processing". Deselect everything except your audio track. Make sure "demux" is selected. Now click the dvd icon in the lower left corner. It will give you a ".vob" file (or files) that contains only the audio track.
Open up Super and drag and drop the .vob file(s) to the area at the bottom. Now go to the top left corner where it says "select output container" and choose aac or mp3. Then in the middle, where it says "audio" choose what birate you want. Then right click and choose "output file saving management" to choose the output directory. Then just click "encode active files" at the bottom, and you should be good to go.
Hopefully my instructions were ok enough, and let me know if I can clarify anything.