music.bin and sfx.bin being the main audio files have been seen in one of the major alternative audio formats commercial DS games have been seen to use
If you just want to rip it then see if the game has an audio test option and go from that. That or find a position in the game where you can do it. You might be able to variously disable or enable the music and/or sound effects (either by modding the files or by disabling the channels it would use in an emulator).
I had a quick fiddle. Importing things into audacity under various settings got some measure of sensible audio playback when it was not bursting my eardrums (should know better than to use headphones at this point). I don't know if anybody properly figured out the format, though if you wanted to try vgmtrans and maybe vgmtoolbox you might get something.