To troubleshoot a sound issue with RetroArch, follow these steps:

1. Check that DirectX 9 is installed on the PC. DirectX 9 is not part of Windows 11 by default and if you are running retroarch via an external drive, i.e. usb key, on a new machine it may not have the necessary runtime installed. It can be downloaded here: LINK Note: when the installer is run it will ask what folder to use. This folder is just a temp folder, essentially it is asking where the contents should be extracted. Once the process is finised navigate to the folder you chose and run the DXSETUP.exe file. Once this file has run you can delete the temp folder.
2. Check if the RetroArch program is muted by pressing random keys on your computer. If it’s muted, go to Settings > Audio and turn off Mute.
3. If the sound issue persists, try setting the default audio driver to Wasapi and unchecking WASAPI Exclusive Mode and WASAPI Float Format.
4. If the volume mixer is the culprit, check if it’s listed on the volume mixer and check if RetroArch was set to low volume or muted. If it’s not listed, try downloading a new copy of RetroArch from their website and extracting it into a new directory.
5. Restart after trying the solutions above.