How loud is a classroom?
An empty classroom should be no louder than 35 dBA under the ANSI/ASA S12.60 classroom acoustics standard, but occupied classrooms are far louder: commonly 65 to 77 dB(A) during teaching according to a 2026 review, and 61.2 to 67.8 dBA in a Quebec classroom study.
- Level
- 35–77 dBAA-weighted sound level
- Daily limit
- No daily limitNIOSH, at the loud end
- Versus conversation
- 1/4.5 energyabout 1.6× quieter
What the numbers mean
How it was measured. 35 dBA is the ANSI/ASA S12.60 maximum for an unoccupied classroom; occupied classrooms during teaching measured 61 to 68 dBA (Quebec case study) and 65 to 77 dB(A) across studies (2026 review).
Classroom acoustics standards set a quiet baseline so that a teacher's voice stands out. The ANSI/ASA S12.60 standard caps unoccupied background noise at 35 dBA, a figure derived from a +15 dB signal-to-noise target and a minimum speech level of 50 dBA. The WHO likewise recommends that background noise in unoccupied classrooms not exceed 35 dB(A).
Real classrooms rarely meet it even when empty. A Quebec case study measured 38 dBA in an unoccupied classroom, and during instruction mean LAeq values ranged from 61.2 to 67.8 dBA. A 2026 review in Noise & Health found classroom exposure levels commonly between 65 and 77 dB(A), with field surveys in primary classrooms at 70 to 77 dB(A) during teaching.
Most of the noise comes from the children themselves, amplified by hard surfaces. Reverberation matters as much as level: S12.60 also limits reverberation time to 0.6 seconds for classrooms smaller than 283 cubic metres (0.7 seconds for larger ones), because echoey rooms blur speech.
How long is safe?
Below 85 dBA, the level NIOSH allows for a full 8-hour day.
| Level | NIOSH limit (85 dBA, 3 dB rule) | OSHA limit (90 dBA, 5 dB rule) | UK/EU 80 dB(A) action value reached after | UK/EU 85 dB(A) action value reached after |
|---|---|---|---|---|
| 77 dBA | No limit | No limit | Not reached in 24 h | Not reached in 24 h |
Times are for a whole day’s exposure, with the rest of the day quiet. The workplace limits were written for adults at work, not for children. Work out a mixed day with the noise dose calculator.
Protecting your hearing
Hearing damage is not the usual concern; understanding speech is. Soft furnishings, acoustic ceiling tiles, felt pads on chair legs and seating children with hearing difficulties near the teacher all help.
Earplug and earmuff ratings (NRR in the US, SNR in the UK and EU) are lab figures; real-world protection is usually lower. How to read the ratings.
Compared with sounds nearby
Using midpoints of each range. Energy multiplies by 10 every 10 dB; perceived loudness roughly doubles (why).
- Open-plan office (49–55 dBA): this has about 2.5× its sound energy and sounds about 1.3× as loud.
- Snoring (45–61.7 dBA max): this has about 1.8× its sound energy and sounds about 1.2× as loud.
- Neonatal intensive care unit (55–63 dBA): it has about 2× the sound energy of this and sounds about 1.2× as loud.
- Dishwasher (38–85 dBA): it has about 3.5× the sound energy of this and sounds about 1.5× as loud.
- Normal conversation (55–70 dBA): conversation has about 4.5× the energy of this.
Questions
What is the recommended noise level for a classroom?
ANSI/ASA S12.60 sets 35 dBA as the maximum for an unoccupied classroom; WHO also recommends 35 dB(A).
How loud is a classroom during lessons?
Measured levels are typically about 61 to 77 dB(A) during teaching.
Sources
- The Auditory Environment at Early Intervention Groups for Young Children With Hearing Loss: Signal to Noise Ratio, Background Noise, and Reverberation, Ear and Hearing. Supports: dB_low: 35 dBA unoccupied (ANSI/ASA S12.60).
In the revised version, ANSI/ASA S12.60-2010 Part 1, the recommendation of 35 dBA was retained
Checked 2026-11-02. - Acoustic Conditions and Student Perceptions in a Québec Classroom: A Case Study, Noise & Health. Supports: 61.2 to 67.8 dBA during teaching.
during instruction, all mean LAeq values ranged from 61.2 to 67.8 dBA
Checked 2026-11-02. - Acoustic Conditions and Student Perceptions in a Québec Classroom: A Case Study, Noise & Health. Supports: 38 dBA unoccupied.
Background noise in the unoccupied classroom, measured over a 1-hour period, was 38 dBA.
Checked 2026-11-02. - Integrated Effects of Environmental and Classroom Noise on Attention and Learning in School-age Children, Noise & Health. Supports: dB_high: 77 dB(A).
Field surveys in primary classrooms measured sound levels between 70 and 77 dB(A) during teaching activities
Checked 2026-11-02. - Integrated Effects of Environmental and Classroom Noise on Attention and Learning in School-age Children, Noise & Health. Supports: 65 to 77 dB(A).
Classroom exposure levels commonly ranged between 65 and 77 dB(A)
Checked 2026-11-02.
This page is general information, not medical advice. If you have ringing in your ears, muffled hearing or any change in your hearing, see an audiologist or your doctor.