It was really annoying when we do whatever we can , alsamixer .. rebooting your machine.. and still you will not hear anything after connecting your headset. Just give the below command : alsactl restore jino@ndz:~$ alsactl restore alsactl: state_lock:125: file /var/lib/alsa/asound.state lock error: File exists alsactl: load_state:1683: Cannot open /var/lib/alsa/asound.state for reading: File exists Found hardware: "HDA-Intel" "Realtek ALC233" "HDA:10ec0235,1179f912,00100002 HDA:80862882,1179f91b,00100000" "0x1179" "0xf91b" Hardware is initialized using a generic method This immediately "restores" the headphones for me. Must be a bug in Ubuntu 16.04. Cheers.