The Google Chrome team is currently testing a new option that will allow users to permanently mute audio coming from a website (URL).
The option is only available via the Google Chrome dev branch, also known as Google Canary.
To permanently mute a website, users have to click the info "ⓘ" button to the left side of each URL. In the dropdown that appears, users must select the "Sound" option at the bottom of the list, and choose one of the three settings.
This option is not available by default in Chrome Canary, and a small trick is needed to make it appear in current distributions. Just follow the steps below:
Step 1: Find your Google Chrome Canary icon/shortcut and double click on it.
Step 2: Select "Properties" from the drop-down menu.
Step 3: In the "Target" field, add the following text "--enable-features=SoundContentSetting" and hit "Save."
This is not a final feature, and because it made it into testing under the Canary branch doesn't mean it will be included in the Chrome Stable version.
You can follow how work and discussions go around this feature's implementation on this Chromium source code review page.
Previous "under testing" features that made it in the Chrome Canary builds include pop-up warnings for when malicious Chrome extensions hijack the browser's proxy settings or its new tab page.