MuteTab is a Chrome extension that helps you manage the sound coming from tabs in Google Chrome. It helps you to find which tab(s) are making sounds and provides browser-wide management of tab muting (calling JavaScript functions where available, otherwise hiding it from the page), including automatically muting all background tabs.
It does not, however, universally allow muting a video or game so that it can be played silently while listening to background sounds coming from another tab. (This is not possible in Chrome without either plug-ins such as Flash being updated or Chrome's plug-in architecture undergoing an unlikely major redesign.)
