Some web pages start playing ads and bellowing at you when you load them. I HATE it. On Chrome I have to right click the tab and select "Mute tab". The result is that the little speaker icon on the offending tab shows a slash across it.
To allow the tab to play again, you have to right click it, and select "un-mute tab".
It sucks. I hate it and I wish muted tabs were the default. Short of that, this is a quicker way to shut the tabs up...
Use the Mute Tab Shortcuts extension.
- Type chrome://flags/#enable-tab-audio-muting into your address bar and press enter.
- Click Enable and restart Chrome.
Now, when you encounter a lousy, people hating noisy tab, you can just click the audio icon on the offending tab to mute or un-mute it.

Update: 1/5/2018
I have noticed lately that just clicking on the sound icon no longer mutes the tab. You now have to right-click the tab and select "Mute Tab".