"Hi. Oh, right. I can't actually hear you now; I'm not plugged in." [gesture to ear]

I often leave my hearing aids (for lack of a better, all-encompassing word) off when I leave my room at night. My glasses go on - I can barely see in the dark without them - but I don't need to hear to find food or the bathroom. I wonder what the experience is like for a hearing person, running into this situation for the first time? Last night, I ran into a new housemate, and went through the usual dance. Too foggy to lip read; took me a second, too, to figure out that something needed to be said. I feel, though, like I may have left her confused about something.

Not that this bothers me, really. It just seems to come up every now and then. Is there an explanation that might leave people less confused? On the other hand, I also don't want to launch into a lengthy one-sided conversation about why I'm not currently hearable, as my roommate puts it.