That sounds cool... but it's a CD game with Red Book CD audio (from what I can see). Totally different to the voice samples in this game, I'm afraid. I would love to do some voice acting too, looks like I was too late for that project (though it seems they got plenty of people to respond).
Actually, most of the VO in the first LoX game is ADPCM embedded in the data track, and not CD Audio ... but that's not really important.
Replacing sample data in the Knight Rider HuCard might not be too
horrible. There are only a couple of sane ways to store it in a HuCard.
The "fun" would be in trying to figure out where it's stored, and how long it is.
If you're running Mednafen, then you'd put a breakpoint on the Timer IRQ or the HBLANK IRQ, and trace through the code to find out where the pointer to the sound data is stored.
It depends upon just how comfortable you are in assembly code.
Getting replacement data into the appropriate format is unlikely to be too hard.
Sample playback is usually much
simpler than the font hacking that you guys had to do.