Fixing Sound in Ubuntu

If your sound quits working randomly after installing updates via the apt system (via sudo apt-get update && apt-get upgrade) or via the Software & Updates graphical program, it's possible that some of the drivers have not been installed with the latest kernel updates.

To fix this, try running the below command:

sudo apt install linux-modules-extra-$(uname -r)

Reboot.  Your sound should hopefully work again!

If the above command doesn't work (older versions of Ubuntu do not have this package), please see the generic information here:

https://itsfoss.com/how-to-fix-no-sound-through-hdmi-in-external-monitor-in-ubuntu/