Abstract:
Relaxing music, such as classical music, could improve autonomic nervous system function by reducing sympathetic activity and increasing parasympathetic activity, as indicated by an increase in heart rate variability (HRV). However, it is unknown whether Thai classical music, which is considered to be relaxing music, could induce autonomic alterations. This study investigated the effects of classical, heavy metal, and Thai classical music on cardiac autonomic activity, as determined by HRV, using a crossover design methodology. All subjects were exposed to the three music stimulations. Electrocardiograms (ECGs) were recorded before, during, and after music listening. The results showed that the standard deviation of normal-to-normal R-R intervals (SDNN) and low frequency (LF) power were significantly decreased during listening to Thai classical music. The decreased SDNN might be due to a reduction in parasympathetic activity, as indicated by the reduction in root mean square successive difference (RMSSD) and percentage of subsequent R-R intervals with a duration difference longer than 50 ms (PNN50). However, the decrease in parasympathetic activity was not large enough to induce autonomic imbalance as shown by an insignificant change in high frequency (HF) power. A positive correlation between LF power and HF power was also observed during listening to Thai classical music. This suggests that HF power functioned to counterbalance the change in LF power during the listening session. In conclusion, only Thai classical music affected cardiac autonomic function by decreasing sympathetic activity without altering cardiac autonomic balance.
