Elminage Series Sound Effect Problems

[Skies2500]

Title: Elminage Series: Elminage Original, Elminage III, Elminage Gothic, Elminage Ibun
Genre: Japanese Wizardry Clone
Region JP
Format: ISO
The only game that works properly is Elminage II
Tested on windows 7 & Linux

There are 5 games in this series on PSP. And 4 of them have problems with the sound effects. It's like they play too fast and sound too high pitched and weird. And everytime you click something in the menu or move your characters it makes a sound effect. This issue is preventing me from playing them with the emulator.

There is an issue opened on github but it seems no one has found a solution:
github.com/hrydgard/ppsspp/issues/9819

Can anyone look into this?

It sounds like it's because the game uses sceVaudio, but I don't know what that means or how to implement any kind of fix.