BZZ of course, I’ll give it to you step by step,
1. Opened the menu of batocera and clicked on sound settings
2. Look for output device in sound settings (should be the last one)
3. Scroll through the options given to you. it gives you the audio output ports on your computer. mine had: auto, hdmi0,hdmi1,hdmi2,hdmi3,hdmi4, and something called ALC221ANALOG which was my vga output device. There was also a preset called custom
4. I rebooted the system and went on my GameCube page and clicked super Mario sunshine
Then it ran to my surprise. Since mine was vga it was easier for me to find the right output device. For hdmi users, I think it’s gonna take a little more trial and error to find the right one but there are only 5 hdmi output devices to choose from. Auto is what the preset was on and that did not work. I don’t know about custom. I don’t think anybody should really touch that setting. So that’s how it was done. Hope this helps.