Volume Master for Chrome allows you to set separate volumes for different tabs and even boost the sound up to 600%.

To use Volume Master for Chrome, click on the icon and you are shown if there's any audio playing. From there, you can slide the volume bar from 0-600%.

Volume Master for Chrome is effortless to use, lightweight and unobtrusive. Volume Master for Chrome is a pleasantly simple extension that only does the one thing promised. We loved this one.