# The Impact of Noise on Learning in Children and Adolescents: A Meta-Analysis
## 3 Results
### Qualitative Synthesis
#### 3.1.2 Impact of Environmental Noise  
Previous findings highlight the complex relationship between environmental noise and cognitive and academic performance. In [23], it was highlighted that environmental noise negatively influences cognitive flexibility and general executive control, with the effect sizes of noisy environments ranging from 0.54 to 0.62. The study [24] examined calculation performance and found that performance is marginally better in silent conditions and worse in the presence of traffic and classroom noise. Similarly, Ref. [12] reported that the effect of noise level on students' reading comprehension had an effect size of 0.29 and that there was an interaction between noise and age.  
In terms of studies on overall academic performance, ref. [13] identified a moderate negative correlation between urban school noise and GPA and MAP scores, indicating that higher noise levels are associated with poorer academic performance. Additionally, ref. [11] investigated various cognitive and academic domains, including arithmetic, vocabulary, and block design, observing effect sizes ranging from 0.12 to 0.47. Regarding visual selective attention errors, ref. [11] also found that background noise affects divided and selective attention, although not all differences were statistically significant.  
A study on the impact of classroom noise found moderate effects on writing, arithmetic, and reading skills favoring the experimental group in most assessments [15]. Previous research has examined nonword repetition accuracy and verbal processing time, observing significant reductions in accuracy, with reduced bandwidth and differences in processing time, under various SNR conditions [14].  
Small to moderate improvements in listening comprehension, nonverbal processing, and spelling were reported in a study on classroom sound field systems [16]. The relationship between noise and academic performance was examined in a study that found weak positive and negative correlations depending on the specific variables analyzed [18]. Significant negative effects on reading and mathematics were observed, particularly among students with socioeconomic disadvantages and those with English as an additional language [10].  
Small but significant differences in reasoning, vocabulary, and perception scores were found between high- and low-aircraft-noise-exposure groups [17]. Speech perception and listening comprehension were investigated, with significant differences observed under different classroom noise conditions [21]. The impact of noise on verbal memory was explored, demonstrating that adequate acoustic conditions improve working memory and reduce omissions and intrusions [22].  
Ref. [25] found a negative relationship between higher environmental noise levels (LAeqN) and math and reading scores, but it also identified positive links with a better signal-to-noise ratio (SNR). It was found that a better SNR significantly improves children's auditory comprehension [26]. Another study highlighted the importance of a good SNR for sentence recognition, with significantly better performance observed under favorable acoustic conditions [27]. The effects of traffic noise and irrelevant speech on reading comprehension and speed, as well as basic mathematics and mathematical reasoning skills, were investigated, showing that traffic noise moderately impairs reading comprehension and speed, while irrelevant speech has minimal effects [28]. Chronic aircraft noise exposure was found to have a small negative effect on students' reading comprehension and sustained attention [29]. Noise level and type were observed to have small effects on attention, short-term memory, and performance in calculation and reading tasks [30].