SoundTuner
Extension to manipulate background audio. Can lower/increase volume, add pan and mono per tab. Can also save background sounds per website for future visits.
Вам понадобится Firefox, чтобы использовать это расширение
Метаданные расширения
Скриншоты
Другие расширения от Abhinav Neelam
Some web pages use audio elements on a different source domain than the main domain so we can't modify these audio elements and must use default controls.
There's no practical way to detect media elements that are CORS restricted. Therefore, some elements may be missed and you may have to change them manually. This issue, https://github.com/WebAudio/web-audio-api/issues/2453 explains more details.