Silence is not a mere absence of sound. Thoreau had a good image: Sound, he said, is a bubble on the surface of silence which straightaway bursts. Below a froth of noisome bubbles silence flows like an infinite stream.
Again, Thoreau said: "If the soul attends for a moment its own infinity, then and there is silence." It's an old theme, common to Transcendentalist hermits and medieval monks, to philosophers and religious teachers of all cultures: In silence we are in touch with something infinitely greater than ourselves. Even those of us who eschew the mystical know that a measure of silence is necessary to our happiness.
And now we are in the season of the leaf blower, that most pernicious of modern inventions, and most unnecessary. As I write, I hear the steady, peace-shattering whine of a leaf blower attached to a riding mower tidying up the college quad. With a wide leaf rake I could easily keep up with the fellow on the mower -- who looks like he could use a bit of exercise -- without the noise, the pollution, the wasted gasoline.
It was in the chapter on "Sounds" that the author of Walden made his well-known remark about needing "a broad margin to my life." And now, listen -- just listen -- as our necessary white spaces are scribbled over with needless decibels.