Did you know you can mute Chrome tabs? You can right click on the tab and select mute. But there is more. With a little tweak to Chrome you can make the speaker symbol that shows up on a tab (for sites with media) a button that you can use to turn the sound on and off a tab without having to right click or go into the tab.
First: Copy and Paste the text below into the omnibox (you might know it better as the address bar)
Second: Click Enable and then click Relaunch Now
Now you will be able to click the speaker symbol on the right side of any tab to mute/unmute the tab