Firefox: Mute Media

You middle-click a few youtube videos and all start shouting against each other. You enter a website and it immediately slaps sound in you face. How annoying…

But there may be help.

Enter about:config and set

• media.block-play-until-visible to true to only play media that is also in the current tab an do not play the stuff from the background
• media.autoplay.enabled to false to stop autoplaying of some of the media (doens’t work everywhere, not sure why..)
• dom.audiochannel.mutedByDefault sets the audio muted by default – essential for offices
• plugins.click_to_play requires a click to run plugins, such as flash (which you are anyway not using!)