Classroom Noise Meter
A free classroom noise meter that turns your microphone into a live volume display the whole class can see. No audio is recorded, stored or uploaded — the sound is analysed inside your browser and nothing ever leaves the device.
- No signup
- Nothing to install
- Free forever
No audio is recorded, stored or uploaded. The sound is measured in your browser and thrown away immediately.
The microphone is off.
Your browser will ask for permission. Measures loudness only.
Ordinary classroom working noise. Ask the class for quiet, then calibrate to set what silence sounds like here.
How teachers use a noise meter
A noise meter makes volume visible. Instead of you telling a class they are too loud — which is one voice against thirty and rarely lands — the room can see for itself when the bar creeps into the red. Most classes self-correct within a few seconds, without anyone being told off.
It works best when the expectation is set before the task, not during it. Say what level the activity needs, set the sensitivity to match, and let the meter do the reminding.
- Independent writing at Strict sensitivity, where the bar should stay green
- Paired talk at Normal, where working noise is fine but shouting is not
- Practical science or DT at Relaxed, where a busy room is the point
- Whole-class challenges: keep it green for the whole task and the class earns a point
- Guided reading, where you need the rest of the room to stay low
Your microphone, your browser, nothing else
This matters enough to say plainly. The meter asks for microphone access only when you press start, and only to measure loudness. The audio is turned into a single number many times a second and immediately discarded. Nothing is recorded, nothing is saved, and nothing is sent anywhere — there is no server involved at all.
That means it is safe to use with children present, and it is straightforward to explain to a headteacher, a DSL or a parent who asks. Close the tab and there is nothing left. If you want to be certain, the microphone indicator in your browser goes out the moment you press stop.
Getting an accurate reading in your room
Every room and every microphone is different. A laptop next to a projector fan reads a quiet room as noisy; a good external microphone at the front reads it as silent. That is why the meter can listen to your room for a few seconds while it is quiet and set its own floor from what it hears — so "green" means quiet for your classroom, not for an average one.
Sensitivity is separate from that floor. It sets how loud the room has to get to fill the bar, so you can change what you are asking for without re-measuring the room.
Frequently asked questions
Does this noise meter record or store any audio?
No. The microphone signal is converted into a loudness number in your browser and thrown away immediately. No audio is recorded, saved, uploaded or sent to any server, and there is no recording to recover afterwards.
Why does it ask for microphone permission?
Measuring how loud a room is needs a microphone, and browsers rightly require your permission before any page can use one. The prompt appears only when you press start, never on page load, and you can revoke it at any time from the padlock icon in the address bar.
Is it safe to use with children in the room?
Yes. Because nothing is recorded or transmitted, there is no pupil data involved at all — the page never learns anything except how loud the room is at this instant, and it forgets that a fraction of a second later.
The meter says the room is loud when it is quiet. What can I do?
Your microphone is probably picking up background hum from a fan, a projector or the laptop itself. Use the calibrate option while the room is quiet: it listens for a few seconds and treats that level as silence from then on.
Does it work on an iPad or a phone?
Yes, in any modern browser that can reach a microphone. On an interactive whiteboard, check that the board has a microphone — many do not, in which case a laptop at the front works better.