How to mute and unmute audio in Safari tabs in macOS High Sierra
<p>macOS High Sierra's Safari lets you mute audio in any open tabs. You can do this right from the Smart Search field, so there’s no need to click through all your tabs to locate the one you want to silence. If you’re viewing a tab that’s not playing audio, the Audio button in the Smart Search field is white with a blue outline. If the tab is playing audio, the Audio button is solid blue.</p>