Birdsongs and audio-guided mindful breathing: Comparable sadness-reducing effects in the lab.

Natural sounds have shown potential for emotion regulation, with birdsong often identified as a salient and meaningful element. This study investigated the psychophysiological effects of birdsong on sadness, using audio-guided mindful breathing as an active control among participants with and without depressive symptoms. The study included 187 participants (Mage = 21.47, 66.3% female), categorized into 4 groups based on depression levels (depressed, non-depressed) and intervention type (birdsong, mindful breathing). Emotional responses were assessed after each phase (baseline, sadness induction, and birdsong/mindful breathing intervention). Heart rate variability (HRV) indices were used to measure physiological changes. Results show that (1) each stage elicited the target emotions, with hit rates exceeding 75%; (2) sadness induction was effective; (3) both birdsong and mindful breathing interventions effectively reduced sadness, as evidenced by the reversal of sadness effects in both groups; (4) subtle differences in the effects of birdsong and mindful breathing were observed in valence and short-term fluctuations in HRV; (5) no other significant differences were found between the groups. The findings indicate that birdsong has been shown to alleviate sadness similarly to mindful breathing. Although mindful breathing was more effective in enhancing valence, birdsong offered greater benefits for physiological recovery in depressed individuals.