Script to Google Chrome?

While gambling I like watching twitch streams on my second monitor.

I would like to mute / un-mute a keyboard shortcut with Chrome so I do not always have to tab out of the game. I thought a script is the easiest or best suited for this? I just do not have a plan of that kind.

Does anyone have any advice, or can I write something like that?

Alt + F4

In Chrome webstore there's "Mute Tab Shortcuts" as a plugin.

Here you can define shortcuts for one or all tabs.

However, I find it critical that this works, while another application is in the foreground. Would have to try.