Classroom Noise Meter

About the classroom noise meter

Every teacher knows the moment: group work starts, and two minutes later nobody can hear anything. Saying "quieter, please" again and again does not work for long.

This noise meter shows the class how loud the room is. Put it on the board or the projector. When the room is calm, the screen is green with a smiling face. When it gets louder, it turns yellow. When it goes over your limit, it turns red, shows Too loud! and can play a short beep. The class sees it at once, without you saying a word.

It also counts how many times the room was too loud — useful for a class goal, like "fewer than 3 times this lesson".

How to use it

• Press Start the noise meter and allow the microphone
• Talk at a normal level and watch the bar
• Move Too loud above to the level you want as the limit — the dark line on the bar shows where it is
• If the bar barely moves, or is always full, change the Microphone sensitivity
• Press Full screen and show it on the board

Setting it up for your room

• Start in a quiet moment. Let the class work quietly for a minute and see where the bar sits. Set the limit a bit above normal working noise.
• Sensitivity depends on the microphone. A laptop mic in the middle of the room needs a higher sensitivity than a headset or a USB mic on your desk.
• Put the computer in the room, not in a corner. The microphone hears the voices closest to it most.
• The meter only counts a "too loud" when the noise stays over the limit for more than half a second — one dropped book does not count.
• After a "too loud", the room must be calm for a second before the next one counts. That way the beep itself never counts as noise.

Ideas for the classroom

• Group work: yellow is fine, red is not
• Silent reading or tests: set a low limit and turn the beep off
• Class goals: reset the count at the start of the lesson, and reward the class if it stays low
• Transitions: "everyone back to green in 10 seconds"
• Pair it with a Timer or a Sand Clock for timed tasks

Private by design

The microphone sound is measured, not recorded. The page looks at how loud the sound is, many times a second, and throws the sound away. Nothing is saved and nothing is sent anywhere. There is no sign-up and no account. Your limit and sensitivity are remembered on this computer only.

Frequently asked questions

Is this a real decibel meter?

No. It shows a level from 0 to 100, not certified decibels. Every microphone hears differently, so the number is for comparing "louder" and "quieter" in your own room. That is all a classroom needs.

Does it record the class?

No. Nothing is recorded or saved. The sound is only measured, and the measurement is thrown away straight away.

Why does the bar not move?

Check that the browser is allowed to use the microphone (the icon in the address bar), and that the right microphone is the default in your computer's sound settings. Then raise the Microphone sensitivity.

Does it work on an interactive whiteboard or a tablet?

Yes — in any modern browser with a microphone: Chrome, Edge, Firefox and Safari, on Windows, Mac, Chromebook, iPad and Android.

Will the screen go to sleep?

On most browsers the page keeps the screen awake while the meter is running.

Can I turn off the beep?

Yes. Choose No sound, colour only under "When it is too loud".

Good to know

• The microphone works only on a secure (https) page — this site is one
• Full screen works on most devices; on an iPhone the meter fills the window instead
• To check that the microphone works at all, use the Microphone Test

Related tools

• Timer — a countdown for any task
• Sand Clock — a visual timer for the board
• Scoreboard — points for teams
• Spin the Wheel — pick a name at random
• Team Generator — split the class into groups
• Microphone Test — check your microphone