Google Chrome adjust volume per tab

Sounds like Volume Master (Chrome extension) does exactly what you want: https://chrome.google.com/webstore/detail/volume-master/jghecgabfgfdldnmbfkhmffcabddioke

I am the author of this product.

You can active one of chromes flags on chrome://flags

Simply enable the called: Tab audio muting UI control. This works for Mac, Windows, Linux, Chrome OS.

Then if you're using an old browser restart Chrome but on newer ones simply right click on the tab and the option to mute the tab should be there.

Reference: http://www.omgchrome.com/how-to-enable-tab-mute-chrome-feature/