We know that from our experience when we tear up a piece of paper, we can hear a characteristic sound. What is the underlying mechanism behind it? What does the dominant frequency and intensity of the sound depends on? The explanation should agree with the real life cases, here is a few that I observed:

1. Dry paper makes greater sound and higher frequencies than wet paper
2. Paper produces greater sound and higher frequencies if we tear it faster
3. It is hard to tell which one produces greater sound, folded paper or single layer paper
4. Folded paper produce lower frequencies than single layer paper

and also is it the same mechanism that explains the sound produced when we are cutting paper using a scissor?

I expect awesome qualitative answers, or even better with some experimental proves/predictions that everybody can try himself/herself since it is very easy experimenting with paper, for example "if we tear it this way, then you can see the peeling trace..blah2...". I already torn so much paper just to help myself thinking about it.