[Cialug] Tracking down an audio problem

[c]

On ubuntu 14.04 and 16.04, I have a recurring problem that occurs across my
3 main machines.

After video and/or audio have been playing for a period of time (it could
be 1 hour, it might be 15 hours split over several days) Suddenly I get no
sound output.
- sound settings do not show anything is muted.
- Occurs whether I am trying to stream media via a browser, or just play a
flac or mp3 in vlc.
- As soon as I reboot the system, sound returns.

I don't know where to start tracking this down, can anyone suggest things
to check or a strategy to follow in figuring this out?

Machines:
- Desktop running ubuntu 16.04
- NUC running ubuntu mate 16.04 (primarily used to stream video and music)
- Work VMs running ubuntu 14.04 and 06.04

*Machines all have 16+GB of RAM and 240GB+ SSDs

Thanks,
Purcell