Is your classroom too loud? Use this free classroom noise monitor to find out: it listens through your laptop, tablet or board computer and shows a big green, amber or red traffic light that the whole class can see. Pick the activity, adjust the limits in decibels and put it in full screen.
Below you’ll find recommended classroom noise levels and practical ways to bring them down.
Classroom Noise Monitor
Show your class how loud it is. Choose the activity, press Start and put the traffic light on the board in full screen.
Ready
dB
Press Start and allow the microphone.
Sound is analysed in your browser; nothing is recorded or uploaded.
- Time in green
- –
- Too-loud moments
- 0
- Quiet streak
- 00:00
- Average level
- –
- Session time
- 00:00
Levels are A-weighted estimates from your device microphone. Place the device where it hears the whole room (not next to one table), then adjust the limits until the light matches what you want.
Related Tools
- Sound Decibel Meter
Measure the room level in detail: average, maximum and peak.
- Background Noise Test
Check the empty room's background noise against the 35 dB(A) guideline.
- Noise Monitor & Logger
Log noise over a whole lesson or day and download a report.
- Decibel Chart
Show students how loud everyday sounds are.
- Volume Level Comparator
Compare two levels, for example before and after new rugs.
How to Use the Noise Monitor in Class
- Place the device where it hears the whole room, not right next to one table or the teacher’s desk.
- Choose the activity: quiet work, partner talk, group work or whole class. Each sets sensible amber and red limits, which you can fine-tune with the sliders.
- Press Start, allow the microphone and press Full screen to show the traffic light on the board.
- Keep Calm reaction speed so a single dropped book doesn’t turn the light red; switch on the gentle chime if you want an audible cue.
- Use the stats (time in green, too-loud moments, quiet streak) as a positive goal, for example “beat yesterday’s quiet streak”.
Levels are A-weighted estimates, like other dB(A) readings, and devices differ, so treat the limits as a starting point. For more accurate numbers, calibrate the microphone once; see also online decibel meter accuracy.
Recommended Classroom Noise Levels
| Measure | Recommended | Source |
|---|---|---|
| Background noise, empty classroom | 35 dB(A) or less | ANSI/ASA S12.60 and WHO |
| Reverberation time (small classroom) | 0.6 seconds or less | ANSI/ASA S12.60 |
| Teacher’s voice above background noise | at least 15 dB | Common guidance for children’s speech understanding |
A quiet empty room at 35 dB(A) lets a normal teaching voice (about 60 dB at a few metres, like normal conversation) stay well above the background. For comparisons with other rooms, see room noise levels.
Typical Classroom Noise Levels
| Level | Typical situation | Effect |
|---|---|---|
| 30–35 dB(A) | Empty classroom, quiet ventilation | Ideal background |
| 35–45 dB(A) | Quiet individual work | Easy to hear the teacher |
| 45–55 dB(A) | Class discussion | Noticeable background |
| 55–65 dB(A) | Partner and group work | Voices start competing |
| 65–75 dB(A) | Very active class, transitions | Hard to hear; see is 70 dB loud? |
Why Classroom Noise Matters
- Hearing speech: children need a clearer signal than adults to follow speech, especially younger pupils and those with hearing or attention difficulties.
- The noise spiral: in a noisy room people raise their voices to be heard, which makes the room louder still (the Lombard effect).
- Teacher voice strain: talking over noise all day tires the voice.
- Concentration: background talk makes reading and writing tasks harder.
How to Reduce Classroom Noise
- Soften the room: rugs, soft pinboards, curtains and felt pads on chair legs reduce echo and scraping.
- Close the gaps: keep doors closed during lessons and check noisy ventilation or projectors.
- Agree voice levels: a simple 0–4 voice-level scale (silent, whisper, partner, group, presenter) matched to the monitor’s presets.
- Use signals, not shouting: a hand signal or chime brings the room down without adding noise.
- Measure before and after: test the empty room with the background noise test, make a change, and test again.
Can Classroom Noise Damage Hearing?
Ordinary classrooms stay far below the level where hearing damage becomes a risk, which is 85 dB(A) averaged over a working day (is 85 dB dangerous?). Sports halls, music rooms and assemblies can get much louder, so check them and see the safe noise levels chart.
Frequently Asked Questions
What is an acceptable noise level in a classroom?
An empty classroom should be 35 dB(A) or quieter. During lessons, 40–55 dB(A) is typical for teaching and discussion; group work is often 55–65 dB(A).
How do I measure the noise level in my classroom?
Start the monitor above, or measure with the sound decibel meter from the middle of the room for a few minutes. Measure the empty room separately to check the background level.
Does the monitor record the class?
No. Sound is analysed in the browser to calculate a level; nothing is recorded, stored or uploaded.
What is a decibel?
A unit for sound level on a logarithmic scale: every 10 dB sounds about twice as loud (what is a decibel).