My SO snoring in the other room, and the A/C running, and my laptop fan coming on and off. Other than that...silence. Have you ever noticed that even silence is not silent?
All the kids are asleep, the house is clean, the SO is asleep and leaves at 4am, and I have a candy bar with my name on it in the silence of the early night. I think my muse just woke up, the nocturnal night crawler.