aplay /usr/share/sounds/*up.wav # test speaker playback
speaker-test -Dplughw:0 -c2 # test all speakders

# close all sound applications ... including gnome-mixer (volume adjuster in at top right)
sudo modprobe -r $(lsmod|grep ^snd|awk '{print $1}') # to see if snd is in use
ps -ef | grep mixer # to find gnome sound mixer
sudo kill -9 <__id-of-mixer__> # enter id of mixer task(s) here
ps -ef | grep mixer # to ensure gnome mixer gone ... don't restart it yet...

sudo rm /var/lib/alsa/asound.state # remove alsa sound settings
sudo modprobe snd_emu10k1 # determine alsa settings again

sudo alsamixer -V all # do a quick check to see if all settings are ok
speaker-test -c2 -Ddefault -t wav #check if sound working again

sudo alsactl store # if sound working again, write settings