It's a small software that I developed for my classroom. It's super effective for younger students.
It shows monitor the loudness of the classroom. I run it on my laptop to project it on the board.
The classroom starts with 100 points. If they get loud points go down and when they are quite points go up.
I use it when I want my students to work individually and quietly.
You need a mic to be able to use this software. (Most laptops have it.)