Noise Meter for Classroom
Put the level of the room on the wall. Pick a display, set the limit with the class, press Start and go fullscreen on the projector. Audio is processed on this device — nothing is recorded or uploaded.
Press Start and allow the microphone to begin.
Three ways to show the noise
The traffic light is the calmest signal: green under the limit, amber as the room approaches it, red over it. The bouncy balls react to every sound and are the crowd-pleaser for younger classes — just know that making them bounce is fun, so save them for activities where some noise is fine. The meter is the plain number, best for older students and silent work.
What limit should you set?
Useful working targets: under 45 dB for silent tests and independent reading, 65 dB for group work, and treat anything sustained above 70 dB as a reset moment. The reasoning behind those numbers, and routines that make the meter stick, are in our guide to monitoring classroom noise levels.
Does it work on a Chromebook or smartboard?
Yes. It is a web page, so it runs on anything with a current browser and a microphone: Chromebooks, Windows and Mac laptops, iPads and the computer behind an interactive board. It listens through whatever the device uses as its default microphone. One thing to watch for: a board connected over HDMI or USB can register itself as the default microphone even though it cannot hear the room. If the display sits still while the class is talking, switch the input back to the computer's own microphone in the system sound settings. On a school-managed Chromebook, IT may need to allow microphone access for this site.
Is the microphone recording my class?
No. The meter measures how loud the signal is and nothing else. Audio is turned into a level on this device, frame by frame, and discarded immediately — it is never recorded, stored or uploaded, and there are no accounts or ads behind it. The browser asks for the microphone once and remembers the answer, and the microphone is released the moment you press Stop or close the tab. That is the short version for a parent or an administrator who asks.
Readings are estimates from the device microphone rather than a calibrated instrument. For measuring rather than managing — averages, peaks and a level trace — use the full sound decibel meter.