Short-term effects of passive listening to an Indian musical scale on blood pressure and heart rate variability among healthy individuals – A randomised controlled trial

Abstract

Objectives: Listening to music is entertaining but also has different health benefits. Music medicine involves passive listening to music, while music therapy involves active music-making. Indian music is broadly classified into Hindustani and Carnatic music, each having its system of musical scales (ragas). Scientific studies of Indian music as an intervention are meagre. The present study determines the effect of passive listening to one melodic scale of Indian music on cardiovascular electrophysiological parameters. Materials and Methods: After informed consent, healthy individuals aged 18–30 years of either gender were recruited and randomly divided into two groups (n = 34 each). Group A was exposed to passive listening to the music intervention (Hindustani melodic scale elaboration [Bhimpalas raga alaap]), while Group B received no intervention except for a few natural sounds (played once in every 2 min). Blood pressure (BP, systolic, SBP; diastolic, DBP) and electrocardiogram in Lead II were recorded with each condition lasting for 10 min (pre, during and post). Heart rate variability (HRV) analysis was done. Data were analysed using SPSS 18.0 version and P ≤ 0.05 was considered significant. Results: In Group A, the SBP did not change during the intervention but increased mildly after the intervention (P = 0.054). The DBP increased in both the groups during the intervention, significant in Group A (P = 0.009), with an increase of 1.676 mmHg (P = 0.012) from pre-during and 1.824 mmHg (P = 0.026) from pre-post intervention. On HRV analysis, mean NN interval increased and HR reduced in both the groups, but was significant only in Group B (P = 0.041 and 0.025, respectively). In Group A, most of the HRV parameters were reduced during music intervention that tended to return toward baseline after the intervention, but the change was statistically significant for total power (P = 0.031) and low frequency (P = 0.013); while in Group B, a consistent significant rise in parasympathetic indicators (SDNN, RMSSD, total power and HF [ms2]) over 30 min was observed. Conclusion: Unique cardiovascular effects were recorded on passive listening to a particular Indian music melodic scale. The scale, raga Bhimpalas, produced a mild arousal response. This could be due to attention being paid to the melodic scale as it was an unfamiliar tune or due to the features of this melodic scale that led to an arousal or excitation response. In contrast, the control group had only a relaxation response. Exploring electrophysiological effects of different genres, melodic scales and their properties after familiarising with the music may thus be illustrative.