Reading Journal With New Book!

Firstly I do want to say that I did finish the Tao Of Pooh, and I simply love it,
it is now one of my most favorite books. Anyways Now I am reading " The Shape Of Water"
I just got it from the Library today! When I was getting the travel book for Japan :)

"When you sit in silence long enough, you learn that silence has a motion.
It glides over you without shape or form, but with weight, exactly like water.
Its color is silver. And silence has a sound you hear only after hours of wading inside of it. The sound is soft, like flute notes rising up, like the words of glass speaking. Then there comes a point when you must shatter the silence, when you must shatter the blindness of it's words, the blindness of it's light."

That has to be the longest paragraph of a quote that I have chosen. I like it simply because it sounds deep. I think it's somewhat random though, or as Miss Kay would say it has a tangent.
Haha, I don't know why I seemed to pick that out, but I did. :)

My question is, "How does silence have a sound?"
I just don't get it.