Comparative study on birdsong and its multi-sensory combinational effects on physio-psychological restoration

People obtain a host of benefits and increased well-being from multi-sensory experiences in natural environments. In order to examine the effects of multi-sensory combinations, this study thus measured physiological (ST, SCL, α-EEG, β-EEG) and psychological (STAI-S) restoration and the overall perceived quality evaluation with four independent plant landscapes (lawn, rose garden, osmanthus garden and pine forest). Participants (308) were recruited and randomly assigned to 14 independent groups to experience one of the following stimuli: (1) only birdsong; (2) birdsong + photo (4 types); (3) birdsong + odor (4 types); and (4) birdsong + photo + congruent odor (4 types). Note that one group served as a control group. The main findings showed that: 1. Integrating visual stimuli of birdsong improved physiological restoration, and the overall perceived quality evaluation but held no psychological effect. 2. Introducing olfactory stimuli of birdsong had an adverse restoration physiologically and no significant effect on psychological restoration and the overall preference, but enhanced the perceived overall feelings of attraction to the landscape and a sense of overall harmony. 3. Introducing a combination of visual-olfactory stimuli led to increased physiological restoration (only for β-EEG) and overall perceived quality evaluation but also had no significant effect psychologically. These findings indicate that multisensory stimuli resulted in greater physiological and psychological restorations, and positive and negative interactive effects on human well-being, providing insights to further study examining the interaction of different sensory experiences in urban parks.