Perceptual and psychoacoustical characteristics of birdsongs

Birdsongs are widely recognized for their positive effects on human perception and well-being, making them valuable components of soundscape design. This study investigates the perceptual and psychoacoustic characteristics of birdsongs and their potential application in soundscape designs. A total of 100 birdsongs were collected and analyzed using psychoacoustic indicators (loudness, sharpness, roughness, and fluctuation strength). Subjective assessments of the birdsongs were then conducted using 13 semantic differential attributes in a laboratory setting to identify the main perceptual components of the birdsongs and to cluster them based on these components. Principal component analysis identified three principal perceptual components: PC1 (Gentleness), PC2 (High-pitch), and PC3 (Liveliness). Psychoacoustic analysis revealed that gentleness was negatively correlated with loudness, sharpness, and roughness, whereas liveliness exhibited positive associations with these parameters. Cluster analysis based on the perceptual components categorized the birdsongs into four distinct clusters, with Clusters 3 and 4 being most suitable for soundscape enhancement due to their calm and engaging qualities. Linear discriminant analysis classified birdsongs into clusters with moderate accuracy (64%), demonstrating the potential of psychoacoustic parameters for predicting perceptual characteristics. Cluster 3 achieved the highest classification accuracy (73%), while Cluster 4 had the lowest (50%), suggesting overlapping psychoacoustic attributes. These findings provide a perception-driven approach for incorporating birdsongs into soundscape design.