Loona Classroom Noise Meter — See the Noise, Calm the Room
Asking for quiet works better when the room can see its own noise. The meter makes volume visible and impersonal — the bar, not the teacher, says it is too loud — and classes quickly start policing themselves to protect their quiet streak.
Your browser will ask for microphone permission. The sound is analysed on this device only — nothing is recorded, stored or sent anywhere. The meter shows a relative level, not decibels (dB): microphone sensitivity varies, so use it to compare quiet and noisy moments, not as a scientific measurement.
How to Use It
- Press Start and allow microphone access when the browser asks. (Nothing is recorded — see the honesty note below.)
- Set the red-zone threshold to suit the activity: lower for silent reading, higher for group work.
- Project the screen. The bar updates live; the label switches between "Lovely and quiet", "Getting lively" and "Too loud".
- Quiet streaks count the seconds the room stays in the green — challenge the class to beat their record.
How It Works
The meter reads your microphone through the WebAudio AnalyserNode and computes a root-mean-square level from the raw waveform, scaled to a 0–100 bar. Honesty matters here: this is a relative level, not a decibel (dB) measurement — phone and laptop microphones have different sensitivities and automatic gain, so the number cannot be compared between devices or treated as a scientific reading. Within one device and one lesson, though, the comparison between quiet and noisy is real and useful. The audio stream is analysed in memory only: it is never recorded, saved or transmitted.
Frequently Asked Questions
Is any sound recorded or sent anywhere?
No. The microphone stream exists only in this page's memory while the meter runs, is analysed sample-by-sample, and is discarded. Close the tab and it is gone. There is no server involved at all.
Why is it not in decibels?
Because honest decibels need a calibrated microphone. Classroom meters that show "dB" from a laptop mic are inventing precision. This tool shows a relative level — perfect for its real job: helping a class notice and manage its own volume.
The bar jumps around a lot. Is that normal?
Yes — speech is spiky. Judge by the zone the bar keeps returning to, not single spikes like a dropped book or a laugh.