Set Sound Output Via Command Line.
The problem is the output sound channel keeps changing to the dock. There is no “set as default” setting under settings.
A partial solution is as follows.
Determine the sound Channel
The following command will space separated list the available devices
pactl list short sinks
Set the Sound Channel
pactl set-default-sink 'alsa_output.pci-0000_00_1a.0.analog-stereo'
Create an Alias
The above command is too long to easily remember so create an alias for it