Physiological responses to and subjective estimates of soundscape elements

Soundscapes provide complex auditory experiences with emotional content, but there are few and limited objective tools available to investigate the relative benefits of soundscape elements. As part of the Positive Soundscapes (UK) project, the effects of individual soundscape elements on the subjective assessment of pleasantness and arousal were compared with associated physiological responses: Heart Rate (HR), Respiratory Rate (RR) and forehead electromyography (EMG) levels. Eighty subjects listened to 18 × 8 s sound-clips from soundscapes. HR, RR and EMG were recorded and the subjective pleasantness and arousal were assessed on 9 point scales. The data were analysed via a linear mixed-model ANOVA. Listening to sound-clips lowered HR slightly but significantly. Male subjects had significantly lower HR before and during sound-clips than female subjects. More unpleasant sound-clips caused larger falls in HR, which was greater in males. Listening to a sound-clip raised RR slightly but significantly. The more pleasant the sound-clip was judged the greater was the rise in RR. This direct relationship between pleasantness and RR response was greater in males. The EMG tended to be raised by unpleasant sound-clips, in both males and females. Distinctive relationships were found between physiological measurements and the subjective estimates of the pleasantness of the presented sound-clips.