I recently found what was up with it when I wanted to record some screencasts
of my day to day typing with voice control. The default audio device
was randomly being selected from the speaker, the headphone jack on my
microphone and a mystical sound card. All I needed to do was select my
speaker by looking at
aplay -l and exporting the environment
variable ALSA_CARD accordingly (in my case
Now I just keep the speaker unplugged because it has a huge plug that gets way too hot and because audio is for the unsophisticated.