While I most certainly agree that silence(or the illusion of silence relative to the amount of auditory stimulation that we tend to recieve) sometimes is a wonderful contrast and brings as you said "a tranquilizing effect" that I quite enjoy.
However, as others have stated in this thread I am of the philosophy that all those noises are in fact music in and of themselves and I enjoy listening to them.
... but sometimes I really just enjoy not listening to music or any other form of auditory stimulation and just basking in the silence.
I go hiking/kayaking a lot, and when you get out there with no people around, you really realize just how much noisier a community is. During the day I don't really notice all the cars screeching, sirens blaring, and people yelling, but when I get out there it is just completely peaceful.