Need some help

[Shade]

Well, you'll need a JP version of the game, for one thing. Second, you'll need Tinke, which is basically a universal DS ripping tool. There should be a sound pack (usually the easiest files to find/access) somewhere, after you open the game within the program. Then you can extract the sound files to .wav

Forgot to mention, don't know for a fact, but I assume you should be looking for an .sdat file.