Too Noisy Lite is a FREE noise meter for iPhone/iPad. It measures the level of noise in a room and graphically displays whether it is at an acceptable level or not. If the level is acceptable, a smiling face is displayed. If the noise level increases beyond a level of acceptability, the graphic changes to indicate that the noise level is NOT acceptable. In the settings, a teacher/adult can adjust the sensitivity of the meter to go with the activity. A testing situation could be set at a 99% sensitivity level and group work could be set at a much lower sensitivity level. The meter worked when I tried it but, I was not in a large room with a group of kids. By using an Apple Digital AV adapter or a VGA adapter, Too Noisy can be projected on a TV or monitor so kids can learn what noise level is acceptable – cool idea! I would think that the LITE version is worth a try to see if it works for your situation. There is also a PRO version and themed versions available for $.99 each. Check out this great FREE educational app!