To set the difficulty, use the slider. The higher the number is the more sound is needed to set it off. What we've done is that you can run this on another computer, so you can see the score for the mic that is being used without actually looking at the mic computer. To sum up, two computers, but one stealthy one.
This project was used to help monitor noise at a Homework Center in the United States. It works really well, and thanks for the support to the teachers that help at HWC!