Switch audio output from keyboard

Is it possible to switch the sound output(from external display to internal speakers) w/ a command from the keyboard? Or just mute the external display from the keyboard? It's a dell monitor, so keyboard volume controls don't work

I watch sports online and like to mute it during commercials, but it opens ads whenever i try to change it, so i either need to switch volume or mute the output with a keyboard command. Is this possible?