sudo add-apt-repository ppa:ubuntu-audio-dev/ppa; sudo add-apt-repository ppa:team-iquik/alsa; sudo apt-get update; sudo apt-get dist-upgrade; sudo apt-get install linux-sound-base alsa-base alsa-utils gdm ubuntu-desktop linux-image-`uname -r` linux-alsa-driver-modules-$(uname -r) libasound2; sudo apt-get --reinstall install linux-sound-base alsa-base alsa-utils gdm ubuntu-desktop linux-image-`uname -r` linux-alsa-driver-modules-$(uname -r)  libasound2; killall pulseaudio; rm -r ~/.pulse*

Run this

Source:
https://help.ubuntu.com/community/SoundTroubleshootingProcedure