Associations between birdsong environments and momentary human affective wellbeing: evidence from real-world

This is the authors' abstract. We don't add key points for this paper.

BACKGROUND: Exposure to birdsong environments benefits mental health. Different types of birdsongs vary in their capacity to promote positive affect; however, the underlying physical acoustic mechanisms within these complex ecological contexts are not yet understood. METHODS: From March 2020 to May 2025, 2,088 participants contributed 11,631 assessments via the smartphone-based Urban Mind platform. Each assessment included self-reported momentary affective states and an audio recording of the surrounding environment. Seventy-six acoustic features characterising birdsong were extracted and screened via univariable and correlation analyses. Associations between birdsong exposure, acoustic features and momentary affective wellbeing were examined using mixed-effect regression models adjusted for individual- and context-level covariates. FINDINGS: Exposure to birdsong environments was associated with higher momentary affective wellbeing compared with non-birdsong environments (adjusted β = 1.34, 95% CI: 0.95-1.74). A modest interaction was observed for mental health status, with stronger associations among individuals with a mental health condition, while no evidence of moderation was found for gender or age. Acoustic analyses identified greater spectral and tonal variability as key characteristics consistently associated with high affective wellbeing. These characteristics were combined into a composite Dynamic Timbre Index (DTI), and higher DTI values were consistently associated with more favourable affective profiles. Species-level analyses across the Americas, Asia, European Union, and the UK demonstrated convergent acoustic characteristics among high-ranking species. INTERPRETATION: Associations between birdsong environments and momentary affective wellbeing may vary according to acoustic characteristics rather than birdsong presence alone. Objective acoustic characterisation offers a complementary approach for traditional green space evaluation to advance sensory-informed environmental health research and nature-based public mental health interventions.