MuteTab is a free Chrome extension which offers various ways to control noisy tabs.

Clicking the MuteTab button lists all the tabs which are playing sounds now, or have done so recently, and you can mute any of these with a click.

Another click adds sites to a blacklist, ensuring you'll never hear their audio in future. There's also a whitelist for sites you don't want to be muted.

If you're in a hurry, a "Mute all tabs" turns off Chrome audio immediately, or clicking "Mute all background tabs" disables sound on everything but music sites (you can choose what these are).

The Options dialog provides even more control. You could set up Chrome to mute sounds by default, for instance, only playing them on approved sites. Defaulting to "Background muted" means you'll only hear audio from the current or approved tabs, and there are various other settings to explore.

Verdict

Chrome is getting better at managing annoying audio, but MuteTab's whitelist and blacklist features are valuable extras which more than justify the download.