Temporal Development of Heartbeat Intervals in Transition of Sound Stimuli Inducing Different Relaxation Feelings

This paper aims to investigate the temporal development of heartbeat intervals in a transition of different sound stimuli. In the listening experiment, two minutes relaxing musical piece and white noise were employed as the different sound stimuli, and the sound stimuli were played twice alternately after five minutes rest. After the exposure of the sound stimuli, a questionnaire asked the subjects relaxation feeling for rest, noise and music sections, respectively. Psychological result showed that music section induced the highest relaxation feeling and noise section induced the lowest relaxation feelings. Average of heartbeat intervals in music section was larger than that in noise section significantly (P < 0.05). Furthermore, after the transition of sound stimuli, it took about 30-s to change heartbeat interval from previous section. These results support the previous findings that investigated the effects of sound stimuli on heartbeat and will contribute to develop musical system reflecting a user's KANSEI information automatically.