Silence is almost never silent.

I used to live in a pretty decently sized city. The quietest I ever experienced was in an old high-rise apartment after the power went out. I climbed up the seven or so flights of stairs because I needed to get into my unit to grab something, nearly all the residents of the building had vacated or were out of the building for one reason or another, so I was probably only one of about a dozen people inside during the power outage. I don't really know how many were still inside, but I'm sure it wasn't many.

Anyways, after I got into my unit I had to stop and listen for a minute. The windows were all closed and there was nothing. It was so quiet that I couldn't hear anything. At least to my ears that were numbed from the droning of the city. It was a marvelous experience. Normally you hear the buzzing of transformers, rumbles from steps and wheels and other things being moved around, the feint trumming of someone listening to music, and the constant mechanical whirr of the elevators working away. All of that was quiet. It was so still and calm.

I didn't experience that again until I moved into my current residence away from the city. Here I'm so used to the much quieter silence that I can hear the rush of air when the fans from the furnace turn on, I am acutely aware of the bubbling from the pet water fountain we have for our cat in the next room. Even the familiar pattering of my cats paws as he trots down the hallway.

Silence is almost never silent.