Integration of soundscape assessment and design principles into international standards and guidelines for learning environment acoustics

The acoustic environment of schools is critical for effective learning, teaching, and wellbeing, with traditional guidelines prioritizing technical parameters such as noise levels thresholds, reverberation time, and sound insulation. However, the integration of soundscape principles, encompassing perceptual and experiential aspects of the auditory environment, remains underexplored. Gray literature offers a valuable resource for synthesizing reviews, particularly in fields where guidelines and policies are often published outside traditional academic channels. In this review a comprehensive gray literature search plan was developed using four complementary strategies: (1) gray literature databases, (2) customized Google search engines, (3) targeted website searches, and (4) consultation with field experts. Documents were screened for relevance through their abstracts, executive summaries, or tables of contents, followed by full-text reviews. Extracted data included acoustic parameters, user-centered elements, inclusion of wellbeing and soundscape considerations, and mentions of positive auditory stimuli. The search strategy identified 18 guidelines, most addressing traditional metrics like noise level thresholds and reverberation time. However, integration of soundscape principles, positive sounds, and wellbeing was minimal, with only 2 out of 18 guidelines (WELL Building Standard v2 and DQLS Version 3.0) mention soundscape principles, with WELL addressing auditory comfort and DQLS acknowledging natural sounds outdoors. User-specific needs were addressed in 11 guidelines, but user preferences were absent. Wellbeing was linked to acoustics in 6 guidelines, though mostly indirectly. These findings highlight gaps in addressing the experiential and psychological aspects of sound in educational environments.