Back in February 2013, Google has added cool yet useful feature, audio Indicators in Canary Build that shows which tabs are playing audio with animation. Google has disabled this feature by default in Canary on Windows and it has not ported to dev (not sure about this), so no meaning of talking about it in Beta and official stable releases.
Google has disabled it as it needs further tweaks, but you can still enable and use it now by adding a command line flag to Chrome executable on its shortcut Properties.
Enabling Audio Indicators for Chrome Tabs in Canary, Dev, Beta and stable channels
1. Right-click on Chrome shortcut on desktop and select Properties
2. Give space after Chrome.exe in Target field and add –enable-audible-notifications (two hyphens one by one before enable) and click OK to apply the changes.
3. Now launch Chrome from that shortcut, try to visit YouTube.com site and play any video in your browser Chrome tab now shows animation with Audio Indicators.
Using this switch, we’ve successfully enabled Audio Indicators on stable, Beta and Canary channels, its up to you to test and tell this feature is working on dev build as well.