My Thinkpad has a microphone mute button with an indicator light and it works with Ubuntu. I find it very convenient to use.
But I had to configure the shortcut (Setup is i3 + pulseaudio + sxhkd):
/*sxhkd/.config/sxhkd/sxhkdrc (lines 19-20)*/
@XF86Audio{RaiseVolume,LowerVolume,Mute,MicMute}
pulseaudio-ctl {up,down,mute,mute-input}