ShutUp!Tab is a free add-on and tool for Chrome that allows you to mute the active tab permanently via a blacklist of domains. With this tool, you can also mute active tabs or automatically mute tabs from the blacklisted URLs or domains. It's a great way to avoid annoying audio ads or sounds on websites that you don't want to hear.

To use ShutUp!Tab, all you need to do is add a domain or URL to the blacklist, and the extension will automatically mute any tabs from that domain. You can also mute the active tab by clicking on the extension icon in the Chrome toolbar. However, note that in very old versions of Chrome, you may need to enable the "Enable Tab Audio Muting UI" flag in Chrome's settings.

Overall, ShutUp!Tab is a useful tool for those who want to avoid unwanted sounds while browsing the web. It's easy to use and doesn't require any technical knowledge.