The sound of silence.

Can anybody explain me what the sound of silence actually sounds like?
I imagine it to be the sound of nature, with all rustle of us, humans, excluded. Shouldn’t it be the breeze of wind in your ear, maybe interrupted by a buzzing bee or mosquito flying by? The twittering sound of birds, warning each other that an unwanted visitor is approaching, is something I’d allow to be part of the sound of silence. Or the sudden “plop” you hear when a fruit falls from a tree. The pattering of a rabbit fleeing into the bushes, ok, I can live with that being part of the sound of silence.

Last week, I did a 20 kilometer walk in the neighbourhood where I live. For the most part of those kilometers, I found myself in a nature reserve. I saw deer, birds, frogs, mice, ants, you name it…

The one thing I didn’t find, was the sound of silence. There’s always something interfering with it. I heard the noise of cars on the motorway nearby, I crossed the path of chatting people, I noticed playing children somewhere in the distance, a carpenter hitting the nail on the head, the loud growling of a motorcycle…

And just when I thought I didn’t hear anything anymore, at the moment that I thought all side-sounds had died, I start hearing this zoom. I look up, and 15000 feet above me, an airplane has started its descent to Brussels Airport.

Well, here’s my question again: Can anybody explain me what the sound of silence actually sounds like?