You must open the "data" file in a hex editor
and you must remove everything that is before:
"ktss". Then unzip it with Cethleann.
You need a tool to extract and compress "KTSS", I don't know if you can find it, although you should look for tools on Koei Tecmo games like Cethleann to manipulate these files. You can still use Foobar's VGMStream Plugin to play them back and convert them into a recognizable audio format.
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Apparently they are audios in DPS (Nintendo) compressed in Ktss. Converting Audio to DPS and compressing them to Ktss with this tool will it work?
https://github.com/SlowpokeVG/DSP-to-KTSS-converter
And compressing it to Data with Cethleann back (and finishing adding what you removed in the HEX tool)
PS: It would be crazy if all this I'm saying works lol
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Support for Nintendo scrambled audio
https://github.com/Thealexbarney/VGAudio
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(You will need the SDK to convert the desired audio to DSP)