D is for dials

...dials, knobs, meters, and speaker covered one whole wall, and which at the moment was playing nothing.

"Isn't that lovely?" she sighed. "It's my favorite program - fifteen minutes of silence - and after that there's a half hour of quiet and then an interlude of lull. Why, did you know that there are almost as many kinds of stillness as there are sounds? But, sadly...

If you keep up with the challenge from A to Z, you might be able to figure out what book the passage is from. But, shhh... don't share your guess with the rest of us until we get to Z. Let's see how many of you know it!!!