Ubuntu – How to make the microphone unmuted on startup

Every time I boot the microphone is muted. I want it to be unmuted instead.
Of course I can do it by 6 easy steps every time:

1. press sound icon in the upper right of the screen.
2. press "Sound settings…" item in the bottom.
4. switch to input tab.
5. uncheck "Mute" checkbox near a microphone icon.
6. close the window.

But I want it to be unmuted by default.

I guess that in linux world this should be changing 0 to 1 in some line in some configuration file, but I don't really know, where is this line located.

sudo nano /etc/modprobe.d/alsa-base.conf

options snd-hda-intel model=auto enable=yes

BTW, if you prefer to use the gnome editor rather than text editing in the terminal, you could also run gksudo gedit /etc/modprobe.d/alsa-base.conf. As far as I know, it is still better to run gksudo rather than sudo to start gnome/kde/unity applications with a GUI in super-user-mode.