Do not use online conversion websites. They are not verifiable. Instead, use offline, open-source tools:
: Drag and drop your .nds or .sdat file into the application.
VGMTrans is the most reliable, open-source tool for this task. It scans DS sound formats, loads the internal sequences (SSYQs) and soundbanks (SBNKs), and allows direct export to MIDI and DLS/SF2 formats. 2. Foobar2000 with the Game Audio Decoder Plugin
A , however, is freedom. It allows you to: