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/

Running Multiple Channels of Audio Simultaneously in Linux

In Windows, I configure my Realtek audio to play sounds through my headphones (plugged into the front panel jacks) and my speakers (plugged into the rear panel jacks) simultaneously. I noticed in Ubuntu, the default is to mute sound in the rear when a device is plugged into the front. I wanted to stop this behavior, so here's what you have to do. Some people may also be looking to mute the rear speakers when a device is plugged into the front, so I have included both configurations. Download this nifty utility to manage and configure your audio settings by running these commands.

sudo apt-get install gnome-alsamixer
alsamixer

In this application, you can adjust volume and mess with several other settings.

At the bottom of alsamixer, scroll over to the "<Auto-Mute>" option.

To play audio through both headphones and speakers, change Auto-Mute to "Disabled".

To play audio through only one device, change Auto-Mute to "Enabled".

Hope that helps!