Noise.

So I've been listening to the pipes gurgle, especially this weekend, since its been so cold outside. (I have hot water heat and radiators, so there are lots of pipes.) and I thought that they were awfully loud, especially in this room, until I realized that I've never really listened to them before, because my computer has always been on, drowning out background noises. And now that its hum isn't always in the background, I hear the gurgle of the pipes and radiators, a sound that has always been present but not noticed quite as much... until now.