The problem is, when you do want to listen to something, if you're a 200+ open tabs across 10 windows in FF/Chrome user like me, tracking down the individual tabs that are playing audio is damn near impossible.

And please someone don't say I'm doing it wrong....why can't browser programmers expose a list of tabs playing audio, and allow navigation to each from that list? (And the same goes for tabs consuming excessive CPU - in FF, I can see the offending websites in about:performance, and I can close the tab from there, but what if I wanted to navigate to the tab instead?)