Annoying browser tricks

From Instapundit:

THE BROWSER UPGRADE I’D LIKE TO SEE: One where the tab that’s the source of the autoplay audio flashes or something so I know which one to shut down.

To  which I'd like to add a hearty Amen.  When I open a whole list of bookmarks in tabs, and one of them starts playing an annoying advertisement, I have no alternative but to hit the mute button as fast as humanly possible.  I'd like to avoid that.  Some alternatives:

1. Mute all tabs except the one in the foreground. While simple and direct, there are situations where you might want to listen to sound in a background tab.  While listening to music from a browser-enabled cloud player.
2. Mute a tab until a user interacts with it. This would allow a tab to start playing music, but only after you click on it.  Of course, this would be annoying with YouTube's autoplay videos, but I find those annoying anyway.