# The Impact of Noise on Learning in Children and Adolescents: A Meta-Analysis
## 4 Discussion and Conclusions  
The aim of this meta-analysis was to analyze the impact of noise on learning through the academic and/or cognitive performance of non-university students, specifically children and adolescents. To achieve this goal, the following research questions were addressed:  
(a) What is the overall effect of noise on the academic or cognitive performance of students? The results, based on 21 studies and 152 effect sizes, show that noise has a significant negative impact on academic and cognitive performance, with a moderate effect size of \(-0.46\) according to [PERSON]'s guidelines. This finding suggests that as noise levels increase, performance decreases. The statistical significance of this effect, supported by a 95% confidence interval that does not include zero, highlights the importance of considering noise as a critical factor in educational settings. (b) How do characteristics such as noise intensity, noise type, and the age of students influence this effect? The coefficient analysis revealed that the \"Children\" age category (between 6 and 12 years old) led to highly significant results, with an estimate of \(-0.350\) (\(p=0.007\)), indicating that younger students perform significantly worse under noisy conditions. This finding emphasizes the need for effective policies and strategies to mitigate noise in classrooms, especially for younger students, who are particularly vulnerable. Although classroom noise was not statistically significant, it showed a negative trend, with an estimate of \(-0.161\) (\(p=0.436\)), indicating a possible negative relationship between this type of noise and academic performance. Similarly, memory and language functions also showed negative trends, with estimates of \(-0.127\) (\(p=0.461\)) and \(-0.152\) (\(p=0.318\)), respectively. Figure 2: Funnel plot. It is also worth noting that traffic noise showed a positive estimate of 0.477 (\(p=0.088\)), but this result was not statistically significant. This inconsistency may be due to complex interactions with other variables that were not adequately controlled in the included studies. This study has several limitations. First, despite including multiple studies in this meta-analysis, the high degree of heterogeneity among the studies may have influenced the results. Second, variability in the measurement of noise and academic/cognitive performance across studies may have introduced biases. Differences in noise measurement methods (e.g., objective decibel levels vs. self-reported exposure) and variations in the cognitive and academic processes assessed (e.g., reading comprehension, memory, mathematical reasoning) contribute to this heterogeneity. Similarly, differences in participant characteristics (e.g., age, educational level) may influence the extent to which noise affects learning. While this meta-analysis provides a general estimate of the effect of noise on learning, the heterogeneity within it suggests that noise does not impact all students and cognitive functions in the same way. Third, there is evidence of publication bias, as studies reporting significant results are more likely to be published. This may have led to a slight overestimation of the overall effect size. Fourth, the use of the REML method, while appropriate for estimating random effects, assumes that effect sizes follow a normal distribution and may be sensitive to extreme heterogeneity or moderators. Although the REML method provides a robust variance estimation, these assumptions should be considered when interpreting the results. Additionally, there were challenges in categorizing age groups, as the age ranges defined in the studies sometimes overlapped, although they were organized in the most useful way possible for analysis. Lastly, although a meta-analysis aims to generalize results for a broader population, the diversity of the educational contexts and populations studied may limit the universal applicability of these findings.