Mute Tab (WebExtension) от Kelvin

Mute Tab is an addon that helps you quickly mute all tabs with just one button (click).

The toolbar button serves as an ON|OFF switch, once pressed, the icon will change accordingly (the color and shape). Please note that if you want to unmute just one tab, simply right-click on a tab and then click on the "Unmute Tab" item. To mute all tabs except the active tab, please visit the options page. If you manually unmute a tab, the addon will NOT change it, even if you click on the toolbar icon.

Note: to report bugs, please fill the Bug report form on the addon's homepage.