Of all the PSX games I have tested and played using retro arch the one game that has issues is TOMBA. There is a very noisy crackling sound that gets very annoying and forces me to use another emulator to play this game, however other emulators do not have the same smoth performance as retro arch so please fix the sound issue.
You should post this here instead -
https://github.com/notaz/pcsx_rearmed/issues?state=open
that is the actual dev that works on the PSX emulator.