Normally the speakers of your laptop is automatically in mute state when you plug the earphones or headphones, and if you're having problem with the aut-mute function when your plug a headphone or earphones on ubuntu or any linux operating system, means both speakers and headphones are all having
the sound from your machine here is a simple fix :
- Open terminal and hit this command line :
sudo gedit /etc/modprobe.d/alsa-base.conf
- add this line at the end of the line :
options snd-hda-intel model=auto probe_mask=1
- Reboot and done.