No matter how well my students work within their cooperative learning teams, there are always days when I wish they were working a little bit quieter. Here is a great visual for students to monitor their noise level. The app is called TooLoud? and is available through Apple App Store. The version I have is free, but contains ads. For a small price, you can purchase the app without ads.
When I use this with my students, we set a limit for the current dB. I soon found my class monitoring their own noise level and reminding others around them when they noticed the current number was too high. This handy app may not solve the noise level, but it will definitely help create an awareness!