Noise at school is not just discomfort. What research tells us about its effects on children’s health and functioning

The teacher gives an instruction, a pupil looks up - and a moment later asks the child next to him what he was supposed to do. His hearing is fine and he is not inattentive: in a room where conversations hum, chairs scrape and reverberation lingers, he had to put far more effort into separating the teacher’s voice from the background than his classmate in the front row. That effort is invisible from the outside, but it has a price - cognitive and health-related. Below we summarise what the research says on the subject, and what does not yet follow from it.

Why public health concerns itself with noise at school

Public health bodies study noise not because it can be irritating, but because it is a measurable environmental factor with documented non-auditory effects. Annoyance is only one of them - and is itself treated as an important indicator of quality of life. Alongside it, the literature describes sleep disturbance, stress responses, cardiovascular effects in adults and cognitive effects in children [2].

This has to be said plainly: the noise levels found in a typical classroom are not levels that damage the hearing organ. The problem lies elsewhere. The modern definition of health also covers wellbeing and the capacity to communicate, rest and do mental work - and these are precisely the areas that noise at school affects first.

For that reason the World Health Organization sets out a separate recommendation for classrooms. Its Guidelines for Community Noise state that the background noise level in a classroom during lessons should not exceed about 35 dB(A) (L_Aeq), and that reverberation time in a typical room should be of the order of 0.6 s [1].

A child can hear and still not receive the whole message

Signal and background

Speech intelligibility is determined not by how loud the teacher’s voice is, but by how far it rises above the background - the signal-to-noise ratio (SNR). If the teacher speaks 10 dB louder than the background, conditions are good; if the difference falls to zero, the listener receives voice and noise with similar strength. Several things work on that difference at once: conversations in the room, the corridor behind the wall, ventilation, chairs being moved, and reverberation - sound energy reflected off hard walls and ceilings, which smears successive syllables over one another. Reverberation is particularly troublesome because it degrades intelligibility even when the measured sound level seems moderate.

Listening effort

An adult listener usually does not notice that part of a distorted message is reconstructed by the listener - from knowledge of the language, the topic and the context. Younger children are less practised at this: their vocabulary and language experience are smaller, so filling in the missing fragments is harder. They therefore have to devote more attention to deciphering what was said at all. This is described as listening effort. Cognitive resources are limited, so whatever is spent decoding the signal cannot at the same moment be used to understand the content, link it to prior knowledge and remember it. This is not a disorder or a diagnosis - it is the normal cost of working in difficult acoustic conditions, borne by everyone, only to a greater degree by children.

What the research shows

World Health Organization (WHO). Guidelines for Community Noise (1999) is not an empirical study but an expert document summarising the state of knowledge on environmental noise at the time; a separate chapter is devoted to schools and nurseries [1]. From it comes the indication of acoustic conditions that support teaching - background level and reverberation time. The later Environmental Noise Guidelines for the European Region (2018) do review the scientific evidence and set out recommendations for road, rail and aircraft noise, identifying reading comprehension in children as one of the significant effects of exposure to aircraft noise [2]. What cannot be derived from these documents: a specific threshold value above which a given child develops a given health effect.

European Environment Agency (EEA). The report Environmental noise in Europe 2025 estimates the health burden of transport noise on Europe’s population from data reported under the Environmental Noise Directive together with risk functions taken from scientific reviews. For children and young people the report gives - on 2021 data - over 560,000 cases of impaired reading comprehension, some 63,000 cases of behavioural problems and some 272,000 cases of overweight attributable to noise exposure [3]. An earlier EEA briefing devoted solely to children puts it this way: more than half a million children in Europe experience reduced reading ability because of environmental noise from road, rail and air transport (EEA, The effect of environmental noise on children's reading ability and behaviour in Europe, 2024) [4]. That sentence is sometimes quoted misleadingly, so it needs a comment: this is not a count of children individually diagnosed by specialists, but a modelled estimate of the population burden - the number of exposed children multiplied by the risk calculated from epidemiological studies. The estimates also concern transport noise, not the noise generated inside the classroom.

The RANCH study (Stansfeld et al., The Lancet, 2005). An international team studied 2,844 children aged 9-10 from 89 schools around three major airports - Heathrow near London, Schiphol near Amsterdam and Barajas near Madrid [5]. It was a cross-sectional study: exposure to aircraft and road noise at school was determined from noise maps and models and from on-site measurements, while cognitive and health outcomes were measured with the same standardised instruments in all three countries; parents completed questionnaires on socio-demographic factors. The study found an association between chronic exposure to aircraft noise at school and poorer reading comprehension, which persisted after adjusting for some socio-economic factors. What cannot be concluded: that noise was the sole or direct cause of the poorer results. A cross-sectional study describes co-occurrence at one point in time, and schools near airports may differ from others in ways the model did not capture.

Systematic review with meta-analysis (Schiller et al., Journal of Speech, Language, and Hearing Research, 2022). A team from the University of Liège analysed 31 studies of children aged 6-18, examining how noise and impaired voice quality in the speaker affect speech processing [6]. The results were organised along three dimensions: speech recognition, comprehension of longer spoken passages, and auditory working memory. The meta-analysis found that noise reduces accuracy on listening tasks in all three dimensions, and that the size of the effect depends on the signal-to-noise ratio - the worse the SNR, the larger the drop. The effect of a teacher’s hoarse or tired voice was analysed separately and proved weaker than that of noise alone, but not zero. Limitations: these are mostly laboratory or simulated-condition studies of varying methodology; they measure immediate task performance, not long-term educational outcomes.

A Polish field study (Polewczyk and Jarosz, Archives of Acoustics, 2020). The authors documented a comprehensive acoustic treatment of the entire building of Primary School No. 340 in Warsaw - one of the largest primary schools in Poland [7]. Before the work, reverberation times in many rooms were 3-4 times higher than the values permitted by the applicable Polish standard PN-B-02151-4:2015-06 [8], and speech intelligibility was very poor (an STI of 0.31 in the worst case). After the treatment, average STI values in classrooms rose from about 0.5 to about 0.7, and measured sound levels fell most in the canteen (about 10 dB) and in the corridors (about 9 dB). In parallel, 378 pupils and 44 teachers completed a scale of perceived change designed by the authors. Teachers reported improvements in pupils’ understanding of instructions, in concentration, in work pace and in short-term memory, and - as the authors summarise - a clear reduction in pupils’ tiredness and in their own vocal effort. An important caveat: the measurement part is objective, but all these changes in functioning come from questionnaires completed after the refurbishment, in which respondents rated the “before” and “after” from memory. This is therefore not medical evidence but a consistent, though subjective, assessment by the users. One discrepancy is telling: teachers saw a clear drop in pupils’ tiredness, while the pupils themselves reported no difference on that point.

Noise from outside and noise from inside the classroom are not the same problem

Discussions about schools usually blur four different phenomena. The first is environmental noise - road, rail and air - reaching the building from outside; it is the subject of directives, noise maps and EEA reports, and is limited through siting, the building envelope and action at source. The second is noise generated inside: conversations, group work, furniture being moved, equipment. The third is the background level - what can be heard in the room when nobody is speaking. The fourth is reverberation, a property of the room itself, independent of how much noise is made in it.

These phenomena overlap: reverberation amplifies the class’s own noise, and noise from outside raises the background against which the teacher’s voice has to work. They are not, however, the same problem; they are not measured the same way and are not solved by the same means. A finding about aircraft noise is not evidence about the effects of noise during break, and a well-treated classroom offers no protection from through-traffic under the windows. A sound diagnosis in a school requires these layers to be separated.

Who pays the highest price for poor acoustics

The effects of poor acoustic conditions are unevenly distributed. Research on speech intelligibility shows that, under the same conditions, younger pupils lose more - they are less able to fill in an incomplete message from linguistic context [6]. Pupils learning in a language that is not their first are in a similar position: in noise, knowing the language stops supporting comprehension. Conditions are also harder for children with hearing loss, including unilateral or temporary loss, and for pupils with language difficulties, for whom reduced intelligibility compounds existing limitations. Research on school acoustics additionally points to the particular vulnerability of pupils with special educational needs, those using hearing aids, and those still acquiring the language of instruction [7].

This is not a list of medical diagnoses, nor of groups who can be diagnosed with anything on the basis of classroom behaviour. It is a way of saying that a room’s acoustics act as a filter: conditions that are merely a nuisance for some pupils become a real barrier to the content of the lesson for others.

Summary

The research does not entitle anyone to claim that noise at school makes children ill. It does entitle us to a far more practical claim: in poor acoustic conditions the same lesson costs a pupil more attention and a teacher more voice. The evidence varies in strength - from WHO expert documents, through EEA modelled population estimates and observational studies showing associations, to meta-analyses of experimental work and field observations after acoustic treatment - but it points in the same direction.

Good acoustics will not replace good teaching, counselling support or a sensibly organised school day. What they do create are conditions in which the teacher’s voice can be heard and understood, and in which children need not spend so much of their attention fighting the sound background. It is a necessary condition, though not a sufficient one - and that is why it deserves to be taken seriously.

References

1. World Health Organization, Guidelines for Community Noise, red. B. Berglund, T. Lindvall, D.H. Schwela, WHO, Geneva 1999. iris.who.int/handle/10665/66217
2. WHO Regional Office for Europe, Environmental Noise Guidelines for the European Region, Copenhagen 2018. who.int/europe/publications/i/item/9789289053563
3. European Environment Agency, Environmental noise in Europe 2025, EEA Report, Copenhagen 2025. eea.europa.eu/en/analysis/publications/environmental-noise-in-europe-2025
4. European Environment Agency, The effect of environmental noise on children's reading ability and behaviour in Europe, EEA Briefing, 2024. eea.europa.eu/en/analysis/publications/the-effect-of-environmental-noise-on-children
5. Stansfeld S.A., Berglund B., Clark C. i in., Aircraft and road traffic noise and children's cognition and health: a cross-national study, „The Lancet” 2005; 365(9475): 1942-1949. DOI: 10.1016/S0140-6736(05)66660-3; PMID: 15936421.
6. Schiller I.S., Remacle A., Durieux N., Morsomme D., Effects of Noise and a Speaker's Impaired Voice Quality on Spoken Language Processing in School-Aged Children: A Systematic Review and Meta-Analysis, „Journal of Speech, Language, and Hearing Research” 2022; 65(1): 169-199. DOI: 10.1044/2021_JSLHR-21-00183; PMID: 34902257.
7. Polewczyk I., Jarosz M., Teachers' and Students' Assessment of the Influence of School Rooms Acoustic Treatment on Their Performance and Wellbeing, „Archives of Acoustics” 2020; 45(3): 401-417. DOI: 10.24425/aoa.2020.134057.
8. PN-B-02151-4:2015-06 Building acoustics. Protection against noise in buildings. Part 4: Requirements for reverberation conditions and speech intelligibility in rooms, and guidance on testing, Polish Committee for Standardization, 2015.

This article is for information only and does not replace an acoustic measurement or a consultation with a room-acoustics specialist.