Classroom Noise Meter — manage the volume without raising yours

Why a noise meter works when "shhh" doesn't

Telling a loud room to be quiet adds one more voice to the noise. A meter on the screen changes the game: volume stops being the teacher's opinion and becomes something the class can watch and regulate themselves. Group-work classrooms use it as a contract — "keep the bars under the line and the music stays on" — and the feedback loop does the rest. It's the same reason speed-display signs slow traffic where speed-limit signs don't: people self-correct when they can see the measurement.

Set it up in twenty seconds

Tap Start the meter and allow the microphone. Talk at the level you want as the ceiling, watch where the bars sit, and drag the LIMIT slider just above it. The SENSITIVITY slider compensates for quiet laptop mics or echoey gyms. When the room crosses the line, the meter flashes a gentle red tint — capped well inside accessibility flash limits — and, if you want it, plays one quiet tick at the moment of crossing. Deliberately never a horn: the room is already loud, and the signal that works is the one the class sees.

The privacy part, plainly

School tech has to clear a higher bar, so here is exactly what happens: the microphone stream feeds a Web Audio analyser inside the page, which reads a running loudness number — that's the height of the bars. No audio is recorded, stored, or sent anywhere. There's no account, no analytics on the sound, and closing the tab ends everything. If the mic is blocked (or the machine hasn't got one), the meter runs a clearly-labeled DEMO animation instead, so you can preview it before granting anything.

Beyond the classroom

Libraries and study halls run it as the ambient referee; indoor recess gets a "green bars" target; drama teachers flip it around and use it as an applause meter for bows. On the free GOGO dashboard it sits as one tile among your timers and scoreboards, so the whole lesson lives on one screen — and the free GOGO iPhone app adds live scoreboards you can drive from your phone when the games start.

Frequently asked questions

Which microphone does it use?

Whatever the browser offers — the laptop's built-in mic is fine. Room position matters more than quality: put the machine where the class is, not behind the teacher's monitor, and adjust sensitivity to suit.

Does it work offline?

The dashboard version does once the page has loaded — the analysis is entirely local. Nothing about the meter needs a connection.

Is the flashing safe?

Yes — the warning is a slow, gentle tint pulse well under the WCAG three-flashes-per- second threshold, and it becomes a steady tint for users with reduced-motion settings.