My thought is that "stop working" in your situation simply ends up being reverting to the lower quality ,telephone audio. Likely due to some hardware or software limitation. Reverts versus a crash, screen lockup, BSOD, etc.
Have you tried downloading, reinstalling, and reconfiguring any applicable drivers?
Three immediate suggestions:
1) Update your post to include hardware specs and OS with respect to the audio system/setup.
2) Add more details about the software and apps affected.
3) If you have a Windows system look in Reliability History/Management. There may be some error code, warning, or even an informational event that regarding the change back to telephone quality.