Exploring acoustic environment and soundscape in urban courtyards: A systematic review

Courtyards are widely used as semi-open spaces that can support restoration and regulate microclimates in densified urban environments. However, urban soundscape research has focussed on urban open spaces. Following PRISMA guidelines, this systematic review synthesises evidence from 90 studies (retrieved from Scopus up to June 2025) to map the methodological trends, thematic focus, and interdisciplinary intersections of the field. The analysis reveals a gradual shift towards the soundscape approach. (1) Despite acoustic characterisation predominantly relying on sound level parameters (90%, e.g. LAeq), their predictive power for acoustic comfort remains inconsistent within relatively low SPL ranges (IQR = 49.2–59.1 dBA). (2) An increasing number of studies incorporate affective quality attributes (44%) for soundscape assessment. The synthesis (94% of cases) indicates significant associations between acoustic environments and perceptual attributes, though it highlights a context-specific model for the urban courtyard soundscape. (3) While path/infrastructure interventions (92%, e.g. spatial planning) demonstrate quantifiable impact on acoustic mitigation (median attenuation = 2.5 dBA), integrating sound sources with these strategies can enhance overall soundscape quality. (4) In parallel, emerging studies prioritise multi-domain interactions, particularly with thermal environments. Current synthesis reveals complementary cross-sensory effects, in which specific natural sounds can moderate thermal perception. (5) By integrating the climate adaptation framework, the courtyard soundscape can contribute to urban well-being. While spatial factors (e.g. openness) demonstrate comparable impacts on acoustic and other environmental exposures, background sound level (LA90) is specifically associated with restorativeness. Advancing this potential requires developing a multi-domain, resource-efficient approach to soundscape design.