I've been trying different things to get sound in Rayman. Psxvcd did not help. Isobuster neither. Next up is cdmage as per this reddit post
Oh and Tombi EU Pal runs perfectly fine at 50fps with frameskip set to 1. It's one of those games where it isn't too noticeable.
I've tried cdmage without succes with rayman.
Used it before converting to .pbp before, no dice.
This exact issue has been dealt with for other platforms some time ago.
Seems it didn't fix the 3ds port yet.
There's still an open issue referencing this on github.