I recently covered an extension that will automatically mute background tabs in Chrome, keeping them from distracting and annoying you. However, as Ghacks.net points out, Chrome has added a developer feature that will let you mute tabs natively. This means you don't need a third-party extension to get this feature.
For now, the mute button feature is only available in Chrome Dev or Chrome Canary builds. Not sure about your current version? You can check by clicking the hamburger icon (the three lines) in the top right-hand corner and then choosing About Google Chrome from the menu. You should see something like this with the Developer or Canary version name:
If you don't have the correct version, you can always download it from the appropriate link here.
Now that you're using the necessary browser, follow these steps to enable a mute button on each tab that is making noise:
Step 1: Enter chrome://flags/#enable-tab-audio-muting into the omnibox.
Step 2: The setting you need to enable will be highlighted. Click Enable under Enable tab audio muting UI control.
Step 3: Restart your Chrome browser.
There's no guarantee that this feature will make it into the stable build of Chrome, but for a feature this useful, it seems likely.