Last year, Google added a handy feature to Chrome: a speaker icon that show which tabs are playing sounds so you can quickly spot them. A hidden experiment builds on that, allowing you to mute them all with one click.
To enable the feature, enter “chrome://flags/” – the special URL for experiments – and search for ‘tab audio mute control. Once you’ve enabled it, you can simply click the speaker icon in one tab to mute them all.
It’s just a test right now, so the feature may disappear or ultimately be integrated into the browser. I certainly hope it sticks around.