Installing "PulseAudio Volume Control" solved the issue.
Using "PulseAudio Volume Control" I was able to disable the HDMI as an
audio device and it straightened out the 3.5mm built-in issue.
Now I am able to leave the 3.5mm speakers plugged into the computer and
still have audio through the USB h
Public bug reported:
USB Headphones do not play test audio from the "Sound" section of the
configuration application if either of the following are true:
3.5mm speakers are plugged into port
HDMI Monitor is attached to computer
VLC Media player is able to properly choose and play through the USB
