Just encountered something strange (bug?) with the sound option in the emulator itself. When I start a game with the option sound off (--no-sound). The sound is indeed turned off.

When I start the game again with sound on (--sound), the sound stays off. It looks like the info is stored in the related state file (state/<gamename>.sv10). After removing the state file, sound is restored to default.

It is not related to Cps2-gui, but keep this behavior in mind when choosing to turn sound off. I will see if I can find more info on this.

Edit : cps2-gui can now be found in the extra-devel repo (cpse2emu 0.7 is not)