Noise Meter Traffic Light
Turns your device's microphone into a giant green, amber, and red traffic light so the whole class can see when volume is climbing. Adjustable sensitivity, optional shh sound, wall-display mode.
Built by the AbraCalc team
How to play
- Tap Turn on microphone and allow access when your browser asks.
- Drag the sensitivity slider until green/amber/red feels right for your room.
- Tap Wall display to fill the screen so it's readable from the back row.
- Leave Shh sound on to get a gentle audio cue whenever the light hits red.
Turn on the microphone and a big traffic light shows the class exactly how loud the room is: green for a good working volume, amber as a warning, and red when it's time to quiet down. Drag the sensitivity slider to match your space, from a hushed reading corner to a lively group project. Switch on the wall-display mode to fill the screen for a projector or TV, so it's readable from across the room. All of the listening and analysis happens right there in the browser tab — the audio is never recorded, saved, or sent anywhere, so nothing to worry about with student privacy.
Frequently asked questions
- Does this record or save any audio?
- No. The microphone signal is analyzed live in your browser to measure loudness only — nothing is recorded, stored, or sent to any server. Turning the microphone off (or closing the tab) stops all access immediately.
- What if a student's browser blocks the microphone?
- The tool shows a friendly message and keeps working without crashing. Just check your browser's site permissions and allow microphone access, then tap Turn on microphone again.
- How do I make the red light trigger sooner in a noisy room?
- Raise the sensitivity slider. Higher sensitivity lowers the volume needed to reach amber and red, which is useful for spaces that are naturally louder or echoey.