National standards on classroom acoustics: Key descriptors and global perspectives

Adequate classroom acoustics enhance communication, support student concentration, and reduce teachers' vocal effort. Many countries follow standards aligned with international guidelines to meet these needs. The study is the second (and last) part of a review of National Standards, incorporating insights from over 100 experts. Despite challenges such as limited data and complex interpretations, the research synthesizes and standardizes an extensive number of datasets coming from 52 countries. Results are summarized in terms of (1) taxonomy of compliance, (2) key components for learning environments, (3) requirements for ancillary spaces, and (4) interactions between acoustic requirements, occupancy, and geometry of the rooms. The findings try to find common challenges and provide actionable recommendations for improving classroom acoustics globally and locally by two key components, namely, the sound absorption of the room and the control of speech intelligibility. The key descriptors for learning spaces must then be placed in a context of harmonization with ancillary spaces. The work aims to investigate how these requirements are effective in the operational conditions (active and occupied) of the environment. By addressing these issues, the research contributes to advancing acoustic quality in schools, fostering better learning and teaching experiences across diverse educational environments.