Can you get used to noise? Half a century of research on children and chronic exposure

“I don’t even hear it any more” - a sentence heard in almost every school beside a busy road or a railway line. A teacher says it after fifteen years in the same room; pupils who have been here since year one repeat it. It sounds like good news: if nobody notices the trains any more, the problem has evidently solved itself. But the sentence describes a perception, not the conditions - and the question behind it is one researchers have been asking for over half a century. Has full adaptation taken place, or have only some responses become less visible?

What “getting used to it” actually means

The everyday “I’ve got used to it” gathers several very different phenomena into one phrase. Separating them is a condition for understanding the rest of this text.

Habituation is a reduction in the response to a repeated stimulus - the simplest and best-described mechanism. It concerns a specific response to a specific stimulus, not the whole organism and not all behaviours at once.

Adaptation is broader: an adjustment of functioning to long-term conditions, covering behaviour, how work is organised and how one copes. It is possible to adapt to difficult conditions while still paying their cost.

Coping strategies are conscious or semi-automatic ways of reducing disruption: sitting nearer the teacher, watching their face, holding a question until it goes quiet, pausing mid-sentence while a train passes. They are a sign of resourcefulness, not of the problem disappearing.

Masking or ignoring a sound is something else again and should not be equated with habituation - consciously turning attention away from a stimulus can cost effort even when it looks like indifference.

An after-effect is a change visible in a task performed after direct exposure has ended. It matters methodologically: it shows that the moment of noise does not exhaust its significance.

And finally learned helplessness - the term requiring the greatest care. In classic psychological experiments it referred to reduced persistence or difficulty initiating action after earlier experience of a situation the participant could not control. It is a description of behaviour in a particular research paradigm, not a personal trait, not a diagnosis and not a synonym for depression. We return to it in a separate section.

Why the absence of a reaction can mislead

After a few months in the same place a pupil comments on the trains less often, stops turning towards the window, reacts less to the repeated stimulus. They develop strategies for holding concentration and learn to predict when the sound will come - and predictability in itself reduces disruption. These are real changes and there is no reason to question them.

None of them, however, implies that every task is performed as it would be in a quieter place, that communication is undisturbed, that the effort required has stayed the same, or that all physiological responses have ceased. Different systems and behaviours can adapt to different degrees and at different rates - and that spread is the main finding of the studies we now turn to.

Back to 1973

The first question about chronic noise and children concerned the home, not the school. Cohen, Glass and Singer (1973) studied children living in tower blocks built over a busy artery [1]. The methodological idea was simple and ingenious: since road noise weakens with height, the floor of the flat can serve as an indicator of exposure. Children living lower and higher in the same buildings were compared on auditory discrimination and reading, with length of residence and some social factors taken into account.

The authors observed that children on lower floors - and thus more exposed - performed worse on tasks discriminating speech sounds, and that this was related to reading ability. Their interpretation was that certain consequences may persist despite subjective adaptation to noise. That is the authors’ 1973 interpretation, not an undisputed present-day fact - it is best treated as the hypothesis that set later research in motion.

The limitations are significant and typical of the period. Exposure was estimated indirectly, from the height of the flat, not measured. The study was observational - families were not randomly assigned to floors, and floor level may have been linked to rent, and so to a family’s means. Control of confounders was more modest than would be accepted today. Even so, the design proved robust enough to set the direction for decades.

A school cut in half by noise

Two years later came a study whose design would be hard to invent. Public School 98 in New York stood directly beside an elevated railway line - but on one side only. Classrooms on the track side regularly experienced passing trains; those on the opposite side of the same building were markedly quieter. Bronzaft and McCarthy (1975) compared the reading scores of pupils taught on each side [2].

The methodological value of such a design is that many factors are equalised automatically: the same school, the same district, the same staff, the same curriculum and a similar intake. What differs is mainly the side of the building. The comparison found lower reading scores among pupils taught on the side exposed to the trains.

Alternative explanations still have to be considered. The allocation of classes to rooms may not have been random - if, say, particular year groups were systematically placed on one side, the difference could have another source. The rooms on the two sides may also have differed in ways other than noise: daylight, size, furnishings. We do not quote the size of the difference expressed “in months behind” until we can confirm exactly how it was calculated in the full publication.

What happened later at the same school

The story has a sequel, and it is probably the most interesting passage in the whole classic literature. After the findings were published, action was taken at P.S. 98: resilient track components were installed to reduce the noise of passing trains, and acoustic ceiling treatment was carried out in three classrooms. Bronzaft and Lehman (1981) examined what had changed [3].

Before the intervention, reading scores were lower on the noisier side of the building. After it, the difference between pupils on the two sides was no longer observed. It is hard to imagine a more suggestive result: the conditions changed and the difference disappeared.

Caution is nonetheless needed, for several reasons. This was not a randomised experiment - nobody assigned classes to conditions at random. More than one element was changed: the track treatment and acoustic work in some rooms, so the effect cannot be attributed to a single action. Successive year groups need not have matched their predecessors in composition or prior attainment. And finally, a result obtained in one school does not prove that exactly the same measure will work in another. Despite these caveats it was one of the first intervention studies in the field, and it is still cited as a model: diagnosis first, then the change, then the check.

Children near an airport: from the laboratory into the field

By the late 1970s there was a substantial body of laboratory experiments on noise, but it remained open whether their findings bore any relation to reality. Cohen, Evans, Krantz and Stokols (1980) attempted to move this research into a real environment [4]. They studied third- and fourth-grade pupils: 142 children from schools exposed to aircraft noise and 120 from matched quieter schools. Blood pressure, cognitive task performance, persistence on difficult tasks and sense of control were measured.

One recorded finding was that children from the noisier schools more often gave up on a difficult task before their time was up. Interpretation calls for great care. It does not mean the children “became helpless” in the sense of a personality trait - it was an observation of a specific behaviour on a specific task, used as an indicator within the research paradigm of the day. Persistence on a laboratory task is not the same as school motivation, or as anything that could be identified in an individual pupil.

The same goes for the blood pressure results: differences between groups recorded in a population study are not hypertension, and the authors did not call them that. They are an indicator of an average difference between groups, measured under particular conditions - not a medical diagnosis in anyone.

A year later the researchers came back

The central question of this article - whether children get used to chronic noise - was put directly in the same team’s next study. Cohen, Krantz, Evans, Stokols and Kelly (1981) re-examined some of the same children a year later, using the same or equivalent measures [5]. Noise-abatement measures taken in some classrooms were also analysed.

The finding was this: in this particular study, over one year, little evidence of full adaptation was found in the indicators analysed. Differences between groups largely persisted. The abatement measures were associated with a small improvement in some outcomes, including hearing the teacher and certain tasks.

The wording matters and the caution is not excessive. This study does not show that children never get used to noise. It shows that in this sample, over this period and on these particular indicators, full adaptation was not observed. A year is not long in a school career, and a defined set of responses was measured, not everything that might change.

The 1990s: the picture grows more complicated

Evans, Hygge and Bullinger (1995) took a broader approach, measuring several kinds of response at once in children chronically exposed to aircraft noise: physiological indicators, reading scores, memory, quality of life, persistence on difficult tasks, response to auditory distraction and perceived noise annoyance [6].

The most interesting thing is the spread between measures. On some indicators the children showed signs of habituation to auditory distraction - their response to the stimulus weakened, exactly as theory predicts. At the same time other differences between groups were still observed. Both in the same study, in the same children.

This finding is the heart of our question: adaptation of one kind of response does not automatically mean adaptation of all the others. The organism does not “get used to it” as a whole - individual responses habituate, to different degrees and at different rates. The reverse caveat matters just as much: this study does not establish a rule that physiological consequences always occur despite psychological habituation. It shows that the two can coexist - not that they must.

A prospective study: before and after an airport opened

The methodologically strongest project in this set exploited a change nobody planned for research purposes. Evans, Bullinger and Hygge (1998) collected data from children aged about 9-11 before and after a new airport opened, comparing an exposed group with a comparison group over two years [7]. Resting blood pressure, overnight epinephrine and norepinephrine excretion and quality-of-life indicators were measured.

The value of a prospective study lies in the order of events: the baseline was measured before conditions changed, so a difference cannot be explained by the groups having differed from the outset. That is a much stronger design than a cross-sectional comparison.

It does not remove every doubt, though. There was no randomisation - the children were not assigned to conditions; their surroundings changed. The communities around the two locations may have differed in other respects too, and more than one element in the area changed along with the airport. The physiological results have to be read in the context of the whole project rather than as isolated numbers - and, to repeat, they do not allow any individual child’s health to be assessed. These are group-level findings.

What “learned helplessness” meant in these studies

The term appears often enough in the classic literature to need separate explanation - because in everyday use it sounds far stronger than it meant in the research. Evans and Stecker (2004) synthesised this line of work in a review of the motivational consequences of environmental stress [8].

This research examined above all a sense of control: whether a person learns that their own action can change a situation, or rather that it cannot. In the classic experiments, participants who had previously encountered an uncontrollable stressor gave up sooner on a subsequent difficult task. Persistence at a task was a measurable indicator within that paradigm - and nothing more.

The correct formulation is therefore: some studies used the learned-helplessness paradigm and observed behaviour consistent with its predictions. Not: “noise causes learned helplessness in children”. It is not a diagnosis, not a stable trait and not clinical depression - equating these does a disservice both to the research and to people diagnosed with depression.

Do old studies still matter?

A publication date neither invalidates a study nor makes it more credible. An older work retains its value if it was well designed, answered an important question, had its findings re-examined by others, and used a method useful enough for later researchers to adopt. The P.S. 98 study [2][3] meets most of these conditions - which is why it is still cited half a century on.

At the same time older works carry the limitations of their era: smaller samples, weaker exposure modelling (often indirect, like the floor of a flat), less extensive control of confounders, different reporting standards, older psychological instruments, no pre-registration, limited representativeness, and different urban and construction realities - different windows, different insulation, different traffic volumes.

The right attitude is therefore neither to dismiss a 1975 publication nor to treat it as final, but to set it against what has been established since.

Has modern science confirmed the classic claims?

The answer is: partly - and that “partly” is more honest than a simple “yes”. Later research, including the large international projects discussed in our article on transport noise, has confirmed some of the earlier observations about the association between chronic exposure and certain cognitive outcomes and children’s experience. The direction set by the researchers of the 1970s proved sound.

The picture is, however, more complex than the most-quoted sentences suggest. Not all functions show consistent associations. Effect sizes are often small. The type of noise matters - results for road and air traffic are not identical. Findings depend on the methods and measures used. And the notion of adaptation itself turned out to be far more complex than a “got used to it / did not” dichotomy: different responses adapt to different degrees, as the 1995 study already showed [6].

The main limitations

Most of the studies discussed do not meet all the methodological standards accepted today - and that has to be said plainly, though it does not remove their historical value. Adaptation was not measured the same way in every study, and the word “habituation” can refer to very different responses: from an orienting turn of the head to a change in a physiological indicator. Comparing these results calls for caution.

Individual measures have their limits too. Persistence on a laboratory task is not a direct measure of school motivation. Blood pressure is not a stand-alone indicator of chronic stress - it is one parameter among many, dependent on the time of day, activity and the circumstances of measurement. Group results do not establish an individual child’s response; an average difference between groups says nothing about a single pupil.

Differences between the studies themselves come on top: the noise sources differed (road, rail, air), some works concerned the home environment and others the school - and those are not the same. The populations of the 1970s and 1980s lived in different social and construction conditions from today’s. And most importantly: observational associations do not prove a single cause, and most of the works discussed are of exactly that kind.

Summary

Let us return to the sentence we began with: “I don’t even hear it any more.” From a research point of view it is very interesting - it describes a real phenomenon, described and measured many times. It does not, however, answer the question about the quality of the environment, because it speaks of what someone notices, not of what is happening. Research over the past half century shows that different responses habituate to different degrees, and that the weakening of one need not mean the disappearance of the others. It also shows - the school-by-the-tracks study is the best example - that conditions can be changed, and that the change can be visible in the results.

Habituation is one of the ways people adjust to their surroundings, and there is nothing wrong with it in itself. A good school should not, however, require children to make learning to ignore poor conditions their only response to them.

References

1. Cohen S., Glass D.C., Singer J.E., Apartment Noise, Auditory Discrimination, and Reading Ability in Children, „Journal of Experimental Social Psychology” 1973; 9(5): 407-422. DOI: 10.1016/S0022-1031(73)80005-8.
2. Bronzaft A.L., McCarthy D.P., The Effect of Elevated Train Noise on Reading Ability, „Environment and Behavior” 1975; 7(4): 517-528. DOI: 10.1177/001391657500700406.
3. Bronzaft A.L., Lehman H.H., The Effect of a Noise Abatement Program on Reading Ability, „Journal of Environmental Psychology” 1981; 1(3): 215-222. DOI: 10.1016/S0272-4944(81)80040-0.
4. Cohen S., Evans G.W., Krantz D.S., Stokols D., Physiological, Motivational, and Cognitive Effects of Aircraft Noise on Children: Moving From the Laboratory to the Field, „American Psychologist” 1980; 35(3): 231-243. DOI: 10.1037/0003-066X.35.3.231; PMID: 7377650.
5. Cohen S., Krantz D.S., Evans G.W., Stokols D., Kelly S., Aircraft Noise and Children: Longitudinal and Cross-Sectional Evidence on Adaptation to Noise and the Effectiveness of Noise Abatement, „Journal of Personality and Social Psychology” 1981; 40(2): 331-345. DOI: 10.1037/0022-3514.40.2.331.
6. Evans G.W., Hygge S., Bullinger M., Chronic Noise and Psychological Stress, „Psychological Science” 1995; 6(6): 333-338. DOI: 10.1111/j.1467-9280.1995.tb00522.x.
7. Evans G.W., Bullinger M., Hygge S., Chronic Noise Exposure and Physiological Response: A Prospective Study of Children Living Under Environmental Stress, „Psychological Science” 1998; 9(1): 75-77. DOI: 10.1111/1467-9280.00014.
8. Evans G.W., Stecker R., Motivational Consequences of Environmental Stress, „Journal of Environmental Psychology” 2004; 24(2): 143-165. DOI: 10.1016/S0272-4944(03)00076-8.

This article is for information and historical context only. It does not replace an acoustic measurement or a consultation with a specialist.