Abstract
In recent years, music has been attracting attention as a factor that improves the sleep environment. Most studies thus far have examined the effects of music on nighttime sleep or the effects of music therapy; however, the effects of music on napping have not yet been sufficiently examined. This study aimed to investigate the impact of listening to music with a known relaxing effect before napping on the subsequent nap, based on various indices (ex. physiological and biochemical indices). The study was designed as a within-participant experiment, with 13 participants (21.2 ± 0.6 years old) each in the control (silent) and music-listening conditions. In the music-listening condition, music was played over loudspeakers at 50 dB, followed by a 20-minute nap beginning at 14:00. Although the music used in the previous study was found to significantly decrease respiration and heart rate, no significant changes in subjective mood, autonomic nervous system activity, sleep variables, salivary cortisol levels, or performance on cognitive tasks after napping due to music listening were observed in the present study. Furthermore, the results of this study showed that, opposite to expectations, subjective sleepiness was significantly stronger after napping than before napping in the music-listening condition. However, it was suggested that this was not an effect of the music itself but instead the setting of the nap time. This study only examined the effect of a single piece of music on napping, and further validation is needed, considering the type of music presented, the participants' preferences, and the length and timing of the nap.
https://ror.org/01vvhy971 
