Survey of national target values on classroom acoustics

This study summarizes National Standards on classroom acoustics in over 50 countries by surveying dozens of experts on targets and design practices. The data collection addressed challenges in the material's accessibility, translation, and interpretation. The research categorized compliance approaches, key learning environment components, and auxiliary space requirements. The findings indicate target values of 0.6 – 0.7 s for the reverberation time in unoccupied state and 35 dBA for A-weighted background noise levels in classroom environments. However, adherence to these parameters may yield divergent acoustic conditions, e.g., active scenarios, depending on different variables, such as occupancy density, local construction typologies, and broader contextual factors. Despite local differences, the comparative analysis of descriptors from National Standards and expert opinions across the continents highlights a common trend in the evolution of technical standardization in classroom acoustics. Identifying target acoustic values provides concrete, evidence-based benchmarks for designers. Furthermore, considering the interplay between acoustic requirements, occupancy, and room geometry allows for the creation of learning environments that effectively enhance speech intelligibility, ultimately improving the educational experience.