I'm sorry to hear that you're experiencing audio issues in Firefox on Windows 11. Let's try some troubleshooting steps together to resolve this. First, please check if there are any updates available for Firefox. Updating to the latest version might fix the problem. If that doesn't help, try restarting your computer in Safe Mode and check if the audio works there. If it does, it could indicate that an extension or add-on is causing the issue. Additionally, you can try clearing your browser cache and cookies. If the problem persists, we might need to look into your audio settings on Windows. Go to Windows Settings > Sound > Advanced Sound Options and make sure Firefox is not muted or set to low volume. Also go to the sound settings which can be available in the start menu and check if the correct speaker are selected. Let me know how it goes, and we'll continue to assist you until we find a solution.

None of the above worked for me. I did however uninstall all audio drivers which worked.

Windows Settings > Sound > Advanced Sound Options has no option to select any program; no program is listed as muted Chrome works fine, all video is audible, but not in firefox. It happened quite suddenly - listening to Coursera, no sound. Copy link to Chrome, all ok. Have rebooted. No updates pending. Only Google translate, Zhongwen Translate and Downloadhelper are enabled, but have been for years.

Can you hear sound with Developer Edition?