Audio Periodically turns Into a Squared-Off Electronic Noise?

Lately something has been driving me crazy. I'm recording a long audio book. And I'll look over and see the wave form has turned into a squared-off solid rectangle instead of the obvious normal wave forms. I stop the recording and listen to what happened. And it just started recording some horrible electonic static for some reason. There is no corresponding noise in my computer anywhere, and certainly nothing in the room or anywhere else.

Has anyone else had this happen? I'd sure love to figure out and prevent this.

I neglected to take a screen pic of it. But next time it happens, I'll add it.