Visual TimerPut the noise meter on the board and let the class see how loud they are. The balls bounce higher as the room gets noisier; when they keep jumping into the red zone, the screen turns red and a short alarm plays. It turns "please keep it down" into a game students can watch — and win.
Press Start and allow the microphone. Then pick how quiet the room should be: Silent work for reading and tests, Quiet talking for partner work, or Group work for centers — the red zone moves up or down to match. The counter shows how many times the class got too loud, which works well for rewards ("under 3 times and we get extra recess").
Ideas for using it
- Silent reading and independent work (set the line low)
- Group work and centers — keep the buzz at a working level
- Lunchroom, library and indoor recess
- Class rewards: fewer alarms earns points or extra time
Tips
- Try it for a minute with normal talking. If the alarm goes off too often, choose a louder mode; if it never does, choose a quieter one.
- If the balls barely move when students talk, open Adjust and raise the microphone sensitivity — the microphone may be far from the students.
- Press Full screen (or F) to show it on a projector or smartboard. The page requests a screen wake lock where supported. Browsers or devices can still suspend it; keep the page visible and test your setup before class.
- Pair it with a classroom timer for timed quiet work.
Add this classroom noise meter to your website
Teachers can put it on a class website or Google Sites page: paste this free, ad-free embed code into a page that allows iframes. Full screen also depends on the host page and browser allowing it. Check the preview and adjust the iframe height in your site editor if it is clipped; test the published page before an activity.
More classroom tools
Frequently asked questions
Is anything recorded or uploaded?
No. The browser only measures how loud the room is, many times a second, and throws the sound away. Nothing is recorded, stored or sent to our server.
Does it show real decibels?
No — it shows a relative loudness. Every microphone and room is different, so pick the mode that fits the activity, and raise the microphone sensitivity under Adjust if the microphone is far from the students.
Why doesn’t the alarm go off when someone claps once?
The noise has to stay in the red zone for most of a second before it counts, so a single bang or cough won’t set it off. After an alarm it waits a few seconds before it can go off again.
It says the microphone is blocked. What do I do?
Click the microphone or lock icon at the left of the address bar, set the microphone to Allow, and press Start again. On school Chromebooks an administrator may need to allow microphone access.