I found an interesting article about unearthed Aztec whistles on CNN -

http://tinyurl.com/5rum26

. There are sounds from some of the whistles that made me think of the way I felt during the end of Silk. I think you might find the sounds as fascinating and frightening as I did.

I shortened the URL because I am not sure how to make a link when commenting, regular html didn't seem to work.