In fact, true silence is so rare, it is perceived as noise.
In fact, true silence will make you insane. See: http://en.wikipedia.org/wiki/Sensory_deprivation
Can't find the article right now, but they once put people in a completely soundproof room; their minds started to make up sounds and increased their hearing sensitivity to the point where they could hear their own muscles move. I believe the longest one lasted 45 minutes.
This may be the article you were looking for: http://www.dailymail.co.uk/sciencetech/article-2124581/The-w...
Be it the noise of the ventilation system, or car horns outside, true silence rarely exists.
That said, when I am at home there is little else except for the sound of my computer fans as I read a book. But when I am at work, I most certainly choose to control what background noises I listen to. Music is most certainly a part of that.
As for stimulus shutting down self reflection, I find that quite the opposite is true. Different forms of stimulus encourage different forms of self reflection.