Effect of OM Chanting of 528Hz Frequency on Heart Rate Variability, Psychological Wellbeing, and Quality of Sleep in Patients of Hypertension: A Randomised Controlled Trial

Abstract

Background

Hypertension (HTN) is associated with lower heart rate variability (HRV) and multiple psychological and sleep disturbances. OM chanting, a scriptural form of meditation, has been shown to improve multiple cardiac, psychological, and autonomic factors in different cohorts.

Purpose

To investigate the effects of listening to OM chanting composed at 528Hz on heart rate, blood pressure, HRV, psychological general wellbeing, and quality of sleep in patients with HTN.

Methods

Sixty patients with diagnosed Stage 1 HTN were randomised into control and intervention groups. Patients in the experimental group listened to an audio recording of OM chanting daily for one month. Patients in the control group received standard care. Outcome measures were assessed immediately after the first session and at the end of one month.

Results

After one month of intervention, a significant (p < .05) reduction in the pulse, systolic and diastolic blood pressure (DBP), a significant increase in RMSSD, SDNN, PNN50, HF, Total power, and LF/HF ratio was observed at the end of the first session and at the end of the intervention. No adverse events were reported during the trial period. Repeated-measures two-way ANOVA results indicate that significant time-dependent effects of OM chanting on pulse and SBP, and a marginal positive trend of effects on SDNN and RMSSD. Pearson correlation analysis indicates that the intervention group showed decoupling of the BP-sleep link, hinting at a beneficial effect.

Conclusion

Listening to 528 Hz frequency OM chanting for one month reduces pulse and blood pressure, and enhances parasympathetic dominance on HRV analysis. It also improves psychological wellbeing, reduces perceived stress, and improves the quality of sleep. OM can be considered an important non-pharmacologic therapy in HTN. It is convenient, socially, and culturally acceptable, harmless, and in sync with deeply rooted religious/spiritual practices of the community.

Introduction

Scientific studies on Yoga-based therapies play an important role in building beautiful bridges between modern and ancient healthcare approaches, thereby making care tenor inclusive and care-components integral. Meditation and yoga have been shown to reduce blood pressure in hypertensive individuals. ¹ OM chanting, which originated in Hinduism, is a meditation that involves constant repetition of three syllables (A, U, and M) silently or aloud while passively disregarding any internal or external distractions. ² In this process, the particular body vibration that the three phonemes induce is believed to calm and focus the mind and body without the need for intense concentrative efforts. ³ Neurophysiological studies show that it can modulate individuals’ affective evaluations of the emotional stimuli and alter early visual and late neural processing of the stimuli, which results in reduced unpleasant and arousal ratings for the negative stimuli. ⁴ Verbal chanting or listening to ‘OM’ chanting has been shown to facilitate flexible switching between various specific resting-state networks, such as the attentional network, frontoparietal control network, and default mode network, to induce a relaxed state and could improve attention simultaneously. ⁵

Acceptance of OM chanting as an effective means for harmonising the mind, body, and spirit dates to the prehistoric era. The word ‘OM’, symbolically written as ‘ॐ’ in the Sanskrit language, is viewed and revered as much greater than a word or vibration; it is regarded as signature of the Lord. ⁶ It is regarded as an essence of the supreme Absolute, consciousness. Indeed, the symbol ॐ is regarded as ‘Signature of the Divine’. Ancient scriptures state that OM chanting can lead to a state of consciousness called ‘Turiya’ in Hindu philosophy, which is a state of consciousness beyond the three common states of consciousness: waking, dreaming, and deep sleep. ⁷

Heart rate variability (HRV), that is, variation in the time intervals between successive heartbeats, is an important physiological indicator for physical and mental status, and for broad-scope diseases. ⁸ It reflects the dynamic interplay between sympathetic and parasympathetic nervous systems, serving thereby as a window into the adaptability and resilience of the cardiovascular system. HRV has emerged as a valuable non-invasive tool for assessing autonomic regulation, emotional regulation, and overall cardiovascular health. Low HRV has been associated with various adverse health outcomes, including an increased risk of cardiovascular disease, hypertension (HTN), diabetes, and mortality. Conversely, an optimal level of HRV is associated with health and self-regulator capacity, and adaptability or resilience. ⁹

The present study investigated the effects of listening to OM chanting specifically composed at 528 Hz on blood pressure, HRV, psychological wellbeing, and quality of sleep in participants with HTN.

The selection of 528 Hz frequency was based on several studies which provide a neurohormonal basis of the effect of this frequency in reducing anxiety, increasing happiness and improving cell survival in humans and animals.^{10, 11}

While the positive effect of OM chanting/listening of non-specified frequency on individual parameters has been reported, this is the first study, to the best of our knowledge, which evaluates immediate and long-term (one month) effects of OM chanting composed at 528 Hz in hypertensive individuals.

Materials and Methods

Study Setting and Patient Selection

This randomised control trial was conducted in a rurally based, medical college-associated tertiary care centre in western India after obtaining approval from the Institutional Ethics Committee (IEC/BU/141/Faculty/18/279/2022 dated 28/11/2022).

Informed consent was obtained from all individual participants included in the study. Clinically stable participants of HTN of Stage 1 in the age group of 18–80 years were considered eligible to participate. Exclusion criteria comprised of acute cardiac failure, acute renal failure, symptomatic IHD, hypertensive urgency/emergency, acute or chronic illness, chronic obstructive pulmonary disease, and hyperthyroidism. Out of 60 participants who volunteered for the study, 30 each were randomised into intervention (I) and control (C) groups with the help of the WINPEPI software. Baseline parameters like systolic blood pressure (SBP), diastolic blood pressure (DBP), HRV, psychological general wellbeing index-short (PSWBI-short) ¹² and Pittsburgh Sleep Quality Index (PSQI) were measured after following all standard precautions. The control group received standard care. Intervention group received standard care and listened to OM chanting daily for 15 minutes for one month. The outcome variables were recorded and compared immediately post-intervention and after four weeks.

OM Chanting

The OM chanting was specially composed and recorded at the frequency of 528 Hz by one of the authors of the study, a music therapist and spiritual seeker. Participants were provided an audio recording and a quiet room for listening in the OPD area on Day 1. Subsequently, they were asked to listen daily for 15 minutes at home for four weeks. Compliance was ensured using regular telephonic follow-up.

Outcome Variables

Cardiovascular parameters like SBP, DBP and pulse rate were recorded by a Welch-Allyn digital monitor. HRV was recorded using the Elite HRV CorSense finger probe machine. HRV parameters like RMSSD (Root mean square of successive RR interval differences), SDNN (Standard deviation of NN intervals), PNN50 (Percentage of successive RR intervals that differ by more than 50 ms), Total power, LF power (low frequency power), HF power (high frequency power) and LF/HF ratio (ratio of low frequency-to-high frequency power) were recorded after following all standard precautions. Perceived stress scale, PWBI-short PSQI were used for the assessment of stress, psychological wellbeing, and quality of sleep. ¹³

Analysis

Statistical analysis was done using the study of frequencies, mean and standard deviations, study of correlations with dependent samples using the paired T-test method. A p value of <.05 was considered statistically significant. All demographic data were analysed descriptively. Wherever relevant, for comparing different components paired t-test was used for the same, and p value was derived. The software used was STATA 14.2.

Results

Demographic and Anthropometric Characteristics

The mean ages in the I and C groups were 60.83 ± 12.73 and 58.53 ± 13.93 years, respectively. Male-to-female ratios were 2:1 and 1.5:1 in I and C groups, respectively. BMI was 27.47 kg/m² and 27.46 kg/m² in I and C groups, respectively. Three participants from the intervention group and two from the control group were lost to follow-up. No adverse effects were reported by participants.

Physiological Effects

Detailed results of the physiological effects of OM chanting on HRV parameters of each group are presented in Tables 1 and 2. Comparison of results between the two groups is provided in Table 3. Repeated-measures two-way ANOVA results are provided in Table 4.

Table 1. Comparison of Blood Pressure and Heart Rate Variability Parameters in Control Group.

	Baseline	After Four Weeks	p Value
Pulse	86.21 ± 11.07	85.14 ± 8.30	.301
SBP	138.29 ± 8.23	142.07 ± 12.63	.074
DBP	84.93 ± 6.831	88.36 ± 7.06	.075
SDNN	52.79 ± 26.05	50.68 ± 28.69	.101
RMSSD	60.61 ± 30.10	56.79 ± 30.55	.173
NN50	29.67 ± 22.68	30.5 ± 20.42	.882
PNN50	5.21 ± 9.79	4.25 ± 6.758	.195
LF	159.39 ± 91.53	157.21 ± 84.339	.768
HF	197.5 ± 104.56	184.64 ± 117.68	.144
Total power	356.96 ± 178.703	342.07 ± 179.543	.157
LF/HF	0.86 ± 0.44	1.039 ± 0.61	.061

Table 2. Comparison of Blood Pressure and Heart Rate Variability Parameters in Study Group.

Variables	Pre-intervention	Immediate Post-intervention	Post-intervention (After Four Weeks)
Pulse	86.52 ± 9.209	71.48 ± 5.480**	75.93 ± 7.221##
SBP	143.85 ± 13.988	122.89 ± 8.437**	133.85 ±13.01##
`DBP	88.44 ± 8.234	76.52 ± 5.591**	83.04 ± 9.036##
SDNN	41.77 ± 21.08	61.52 ± 38.45**	56.81 ± 32.88##
RMSSD	59.11 ± 38.37	82.19 ± 51.61**	87.15 ± 71.33##
PNN50	3.81 ±5.292	4.96 ± 7.046	4.96 ± 7.05
LF	169.48 ± 122.06	189.11 ± 116.83	190.07 ± 145.07
HF	187.11 ± 168.214	299.22 ± 242.186**	265.96 ± 171.215##
Total power	356.26 ± 265.604	488.78 ± 327.370**	456.30 ± 294.633##
LF/HF	1.21 ± 0.785	0.85 ± 0.602*	0.735 ± 0.332##

Notes: *p < .05 and **p < .01 between pre-intervention and post-intervention.

^##p < .01 between pre-intervention and after four weeks.

Table 3. Comparison Between Control and Intervention Groups of Blood Pressure and HRV Measures at Baseline and End of the Study.

	Intervention Mean (SD)	Control Mean (SD)	p Value
Difference in SBP	−10.00 (17.016)	3.79 (10.782)	<.001
Difference in DBP	−5.41 (10.375)	3.43 (9.781)	.002
Difference in SDNN	15.24 (22.76)	−1.98 (6.57)	<.001
Difference in RMSSD	28.19 (42.71)	−3.75 (14.47)	<.001
Difference in PNN50	0.41 (3.43)	−0.96 (3.82)	.16
Difference in LF	20.56 (81.63)	−2.14 (38.739)	.31
Difference in HF	78.93 (37.749)	−12.71 (45.12)	<.001
Difference in total power	100.19 (92.837)	−14.96 (54.05)	<.001
Difference in LF/HF	−0.472 (0.69)	0.174 (0.4575)	<.001

Table 4. Repeated-measures Two-way ANOVA.

Variable	Intervention F (1, 106)	p	Measure F (1,106)	p	Interaction F (1,106)	p
Pulse	6.63	.011*	11.36	.001*	7.57	.007*
SBP	0.33	.568	1.80	.183	8.86	.004*
SDNN	0.21	.649	1.59	.210	2.69	.104
RMSSD	2.76	.100	1.97	.163	3.35	.070
LN	1.19	.279	0.84	.360	2.43	.122

Note: Significant effects are indicated by *p < .05.

At baseline, physiological and psychological parameters were comparable between the I and C groups. After the first session of OM chanting, the I group showed a significant reduction in HR, SBP, and DBP, which further reduced at the end of the intervention period (one month). HRV parameters also showed notable improvements; at both the first session and at the study endpoint, the intervention group had statistically significant increases (p < .05) in RMSSD, SDNN, HF, total power, and the LF/HF ratio. No significant changes were observed in these physiological parameters within the control group across the study period. A mixed-design repeated-measures two-way ANOVA was conducted to evaluate the effects of intervention on physiological variables, including pulse, SBP, standard deviation of NN intervals (SDNN), root mean square of successive differences (RMSSD), natural log of RMSSD (LN), and percentage of adjacent NN intervals differing by >50 ms (pNN50). Significant findings (a) The models for pulse and SBP showed significant overall effects, with notable interactions indicating that the intervention’s impact on these variables varies by time. Pulse decreased significantly over time, with a stronger effect in the intervention group, while SBP showed a significant interaction without main effects, suggesting the intervention’s effect is time-dependent. (b) Marginal Effects: SDNN and RMSSD exhibited marginal interactions and, for RMSSD, a marginal intervention effect, suggesting potential trends that may warrant further study with a larger sample or adjusted analysis (e.g., Greenhouse-Geisser correction for sphericity). (c) Non-Significant Findings: LN and pNN50 models lacked significant effects, indicating no substantial influence of intervention or time on these HRV indices in this dataset. These results suggest that the intervention may be effective in reducing pulse and modulating SBP changes over time, with weaker evidence for HRV indices, supporting targeted clinical follow-up (Post-Hoc Analysis: pairwise comparisons by t-tests demonstrate significant effects within groups over time interactions [pulse, SBP]).

Effects on Psychological Parameters and Sleep Quality

The intervention significantly impacted psychological parameters and sleep quality, as detailed in Tables 5, 6 and 7. Participants in the intervention group demonstrated a marked reduction in perceived stress levels and a decrease in anxiety, as measured by the Visual Analogue Scale (VAS) for anxiety. Significant improvement in overall psychological wellbeing and sleep quality was recorded. Although the baseline data showed considerable variations between intervention and control participants for mean scores of PSS (18.48 ± 5.45 v/s 21.54 ± 6.203; p = .058), PSQI (6.48 ± 2.47 v/s 7.57 ± 2.89; p = .14) and overall total PGWBI (18.85 ± 3.146 v/s 17.39 ± 2.362; p = .057). However, chi-square statistics did not find any statistically significant difference between intervention and control groups for any of these psychological wellbeing scales at baseline. Our analysis did not find any statistically significant difference for any of the PGWBI sub-domains between intervention and control groups at baseline (p > .05). Moreover, there was no statistically significant association between groups for differences in these sub-domains from baseline to the end of the study. However, all PGWBI sub-domains showed statistically significant differences between groups at the end of the study (one-month follow-up). For instance, mean scores for self-control at one-month follow-up were significantly higher (p = .009) in intervention group as compared to control group (3.56 ± 0.8 v/s. 3.0 ± 0.72). Similar observations were noted for being positive wellbeing (3.48 ± 0.58 v/s. 3.04 ± 0.64; p = .009) and anxiety (3.48 ± 0.58 v/s. 3.07 ± 0.72; p = .02) sub-domains as well.

Table 5. Psychological Wellbeing and Global Sleep Score in Control Group.

	Pre-intervention	Post-intervention (After Four Weeks)	p Value
PSS	21.96 ± 5.88	21.15 ± 5.47	.582
VAS	2.37 ± 1.39	1.89 ± 0.97	.126
PGWBI ANXIETY	2.89 ± 0.57	3.07 ± 0.72	.134
PGWBI VITALITY_1	2.82 ± 0.67	3.04 ± 0.74	.136
PGWBI DEPRESSION	2.86 ± 0.71	3.18 ± 0.67	.32
PGWBI SELF CONTROL	2.82 ± 0.86	3.00 ± 0.72	.306
PGWBI POSIT_BEING	2.96 ± 0.58	3.04 ± 0.64	.573
PGWBI VITALITY_2	3.04 ± 0.43	3.00 ± 0.61	.802
TOTAL PGWBI	17.39 ± 2.36	18.32 ± 2.74	.164
PSQI	7.59 ± 2.95	6.96 ± 2.44	.37

Table 6. Psychological Wellbeing and Global Sleep Score in Study Group.

Variables	Pre-intervention	Post-intervention (After Four Weeks)	p Value
PSS	18.48 ± 5.445	15.85 ± 4.72	.001
VAS	2.04 ± 0.76	1.74 ± 0.71	.009
PGWBI ANXIETY	3.07 ± 0.68	3.48 ± 0.58	.009
PGWBI VITALITY_1	2.96 ± 0.76	3.44 ±0.70	.016
PGWBI DEPRESSION	3.19 ± 0.79	3.56 ± 0.70	.067
PGWBI SELF CONTROL	3.15 ± 0.66	3.56 ± 0.80	.009
PGWBI POSIT_BEING	3.22 ± 0.85	3.48 ± 0.58	.129
PGWBI VITALITY_2	3.26 ± 0.71	3.41 ± 0.79	.425
TOTAL PGWBI	18.85 ± 3.15	20.93 ± 2.66	.007
PSQI	6.48 ± 2.47	5.04 ± 2.24	.021

Table 7. Comparison Between Control and Intervention Groups of Psychological Wellbeing Scales and Quality of Sleep.

	Intervention Mean (SD)	Control Mean (SD)	p Value
Difference in PSS	−2.63 (1.98)	−1.14 (2.46)	.017
Difference in VAS	−0.3 (0.54)	−0.54 (0.79)	.198
Difference in PGWBI ANXIETY	0.41 (0.75)	0.18 (0.61)	.22
Difference in PGWBI VITALITY _1	0.48 (0.98)	0.21 (0.74)	.256
Difference in PGWBI DEPRESSION	0.37 (1.01)	0.32 (0.86)	.847
Difference in PGWBI SELF CONTROL	0.41 (0.75)	0.18 (0.9)	.312
Difference in PGWBI POSIT_BEING	0.26 (0.86)	0.07 (0.66)	.367
Difference in PGWBI VITALITY _2	0.15 (0.95)	−0.04 (0.74)	.427
Difference in TOTAL PGWBI	2.07 (2.73)	0.93 (2.32)	.099
Difference in PSQI	−1.44 (1.72)	−0.86 (1.74)	.213

Pearson Correlation Analysis

SBP, DBP, PSQI, and Total Power are shown in Table 8. (a) In control group, there was a notable strong negative diff for SBP-PSQI (changes in SBP and sleep quality move oppositely) and moderate negative correlations for Total Power and PSQI before/after. (b) In the intervention group, there was a moderate positive baseline for SBP-PSQI that weakened post-intervention. Moderate negative diff for Total Power-PSQI, suggesting potential benefits from the intervention (i.e., OM chanting). (c) For all participants, there was a weak positive correlation between SBP and PSQI after the study (higher blood pressure linked to poorer sleep). These findings align with literature linking poor sleep (high PSQI) to higher blood pressure and lower HRV. However, small sample sizes and potential confounders limit generalizability.

Table 8. Pearson Correlation Analysis: SBP, DBP, PSQI, and Total Power.

All Participants (n = 55)	Variable Pair	Before	After	Diff
	SBP and PSQI	0.146	0.297	−0.033
	DBP and PSQI	0.131	0.076	0.079
	Total power and PSQI	−0.160	−0.211	−0.211
Control group(n = 28)	SBP and PSQI	0.052	0.338	−0.663
	DBP and PSQI	0.197	−0.192	0.066
	Total power and PSQI	−0.343	−0.352	0.135
Intervention group(n = 27)	SBP and PSQI	0.334	0.087	0.232
	DBP and PSQI	0.182	0.063	−0.045
	Total power and PSQI	−0.029	0.002	−0.310

Note: Strength interpretation: |r| < 0.3 (weak), 0.3 ≤ |r| < 0.5 (moderate), |r| ≥ 0.5 (strong).

Discussion

Results of our study indicate that listening to OM chanting composed at 528 Hz frequency produces immediate and sustained autonomic modulation, as evidenced by an increase in parasympathetic dominance on HRV analysis, a reduction in HR, SBP, and DBP. These changes are accompanied by an improvement in psychological wellbeing and quality of sleep. A significant difference in HRV of hypertensive and normotensive individuals has been reported in the Indian population. ¹⁴ Changes in HRV document association between psychological processes and physiological reactions observed in many meditative practices, including OM chanting, which enhances parasympathetic activity and reduces sympathetic dominance. Given the bi-directional association between physical and psychological factors in genesis and control of HTN, results of the study provide a significant basis to widen therapeutic approach by incorporating interventions founded on spiritual practices.

The OM recitation used in the study was composed at 528 Hz. Sound of 528 Hz. frequency has been identified as ‘healing music’. Frequency 528 Hz (also known as ‘love frequency’) has been identified as one of the most important frequencies for transformation and DNA repair, which also helps to increase awareness. ¹⁵ While studying effects of listening to two different music compositions of 528 Hz and 440 Hz on salivary biomarkers of stress (cortisol, chromogranin A, and oxytocin), it was found that with 528 Hz music, mean levels of cortisol significantly decreased, chromogranin A tended to decrease, and oxytocin significantly increased after music exposure as compared to music composed at 440 Hz.^{10, 16}

There are many studies demonstrating beneficial effects of OM chanting with or without other yoga practices for short duration on one or two parameters, but simultaneous documentation of listening to OM composed at a specific frequency on physiological, psychological wellbeing and quality of sleep parameters over one month’s intervention is hardly reported. An increase in parasympathetic dominance, as reflected in increased HF power and improved time domain parameters observed in our research, offers a mechanism that indicates a critical role of parasympathetic modulation with its resultant effects.

A 12-minute group chanting of OM through vocal or silent repetition in healthy individuals revealed that both vocal and silent chanting resulted in significant decreases in salivary cortisol levels and self-reported anxiety. ¹⁷ Beneficial effects of OM chanting combined with yoga nidra, offered 5 days a week, have been shown to improve physiological and psychological parameters. ¹⁸ Combination of the two well-known relaxation practices of yoga nidra and OM chanting has been shown to be beneficial in reducing high BP and lipid profile in patients with HTN. ¹⁹ In a study of brief chanting of OM (5 min) in experienced and non-experienced yoga practitioners, it was observed that yoga practitioners demonstrated a significant increase in HF power, a component of the parasympathetic nervous system. This increase is positively correlated with the years of experience in yoga. ²⁰ In contrast, our study observed significant improvements across multiple HRV parameters in participants with no prior experience in yoga or meditation. It has been shown that after six months of OM chanting under the supervision of a yoga teacher, blood pressure, pulse rate, depression, anxiety, and stress decreased significantly. ²¹

It has been reported that poor quality of sleep correlates with the degree of blood pressure and low-density lipoprotein levels. ²² Improving sleep quality has been shown to have potential to lower BP and optimise HTN management at the population level. ²³ Yoga-based interventions have been shown to be effective in improving quality of sleep. ²⁴ However, the effect of OM chanting on sleep quality in large and long-term cohorts has not been reported. We observed significant improvement in quality of sleep in the intervention group, which can be explained on the basis of physiologic changes as well as scriptural explanations.

Pearson correlation of blood pressure and HRV parameters with quality of sleep in the intervention group shows that correlation between SBP and PSQI decreased post-intervention (0.334 → 0.087), suggesting that SBP became less predictive of poor sleep. This may reflect improved autonomic regulation—a hallmark of enhanced HRV—where sympathetic overactivity (linked to elevated SBP) is calmed. A similar decline in correlation between DBP and PSQI (0.182 → 0.063) in the intervention group implies reduced vascular tension and better parasympathetic balance, often seen with meditative practices. According to spiritual insights, OM chanting is not merely a vocal exercise—it is a vibrational alignment with universal rhythm. According to physiological studies, OM chanting induces cardiorespiratory synchronisation, enhancing vagal tone and HRV coherence. This may explain the stabilisation of BP–PSQI correlations and the softening of HRV–PSQI links. It has also been reported that mantric repetition of OM quiets the mind, reducing ruminative thoughts and hyperarousal—key contributors to poor sleep. This aligns with the observed attenuation of BP–PSQI correlations. OM chanting has also been shown to activate the parasympathetic nervous system, fostering a state of restful alertness. The flattening of HRV–PSQI correlation observed in our study may reflect a shift from reactive physiology to equanimous baseline functioning. The intervention group’s trends suggest a harmonisation of physiological and psychological rhythms, likely catalysed by OM chanting. In contrast, the control group showed erratic shifts—perhaps reflecting the absence of a stabilising inner practice.

Spirituality is understood as ‘dynamic and intrinsic aspect of humanity through which persons seek ultimate meaning, purpose, and transcendence’ ²⁵ and religion as the search for significance within the context of established institutions oriented to facilitating spirituality.

Hindu scriptures such as Veda, Upanishad, Gita and Patanjali Yoga Sutra abound with the importance of OM chanting for spiritual enlightenment. It has been described as the force behind all thoughts and it has been declared that chanting or thinking about OM will cause a quiet mental state. ²⁶ The practice of OM chanting is interwoven in the daily life of people engaging in many religious-spiritual practices for invocation of Divine Blessings. OM is the initiating syllable pronounced at the outset as a benedictory prelude and sanction to all acts of sacrifice, all acts of giving and all acts of askesis; it is a reminder that our work should be made an expression of the triple Divine in our inner being and turned towards him in the idea and motive. ⁷

OM chanting has transcended its Hindu origins. Its benefits are recognised and practised across various cultures and spiritual traditions such as Buddhism, Jainism, Sikhism, Sufism and Taoism in one or the other simile. This is founded on the acceptance of the power of sound as energy that promotes spiritual growth. New Age and Spiritual Movements include OM chanting, which is a loosely cohesive conglomerate of different spiritual currents. It emphasises both the unity and diversity of the New Age. ²⁷

Our study contributes to the growing body of evidence supporting yoga, meditation, and mantra chanting—particularly OM recitation—as effective, culturally rooted, non-pharmacological interventions in management of HTN. In our study, participants from diverse religious backgrounds engaged with the OM intervention without hesitation and reported positive outcomes.

There are several strengths of the study: This investigation uniquely focuses on the under-researched area of specific frequency (528 Hz) ‘OM listening’. We demonstrated benefits in multiple parameters, namely, HRV parameters, PSQI scale, and PGWBI scale, which provide evidence of comprehensiveness of its effect. Our intervention does not involve any physical activities (like yogic postures/asanas) or daily attending yoga clinics, and therefore does not interfere with their regular schedule of life. It is a no-cost intervention which is convenient, socially, and culturally acceptable. It is harmless. It is in sync with deeply rooted religious/spiritual practices. It is an important mediator of enhancing holistic health, improving the quality of sleep, and controlling blood pressure. Home-based OM chanting may nurture self-care practices for a better quality of life.

Some limitations of the present study provide directions for future research: Additional assessments, such as self-reporting reflective notes, ambulatory blood pressure monitoring at the commencement and end of the study, baroreceptor sensitivity, photoplethysmography, respiratory rate changes along with HRV, imaging techniques, and galvanic skin resistance would have given a better understanding of multidimensional and multilevel effects of OM chanting. An application-based delivery of the OM recording would have helped in documenting time and duration of each OM chanting session. The study’s validity would be further bolstered by extending the intervention period, incorporating extended-term follow-up (over months to years), and increasing the sample size.

Results of present study may be used as small but significant evidence of effect of OM chanting on multiple dimensions of human physiology in hypertensive participants

Conclusion

OM composed at a frequency of 528 Hz has significant effects on autonomic modulation, psychological wellbeing, and sleep quality in participants with HTN.

Recommendations: These findings reinforce the therapeutic potential of a spiritual practice of OM chanting as a non-pharmacological intervention for HTN management. It provides an example of a healthcare intervention which fosters instituting collaborative wisdom of science and spirituality.

Authors’ Contribution

Bhalendu Vaishnav contributed in concept, design and manuscript writing. Arnab Chowdhury composed specific OM recording. Hasmukh Shah contributed in methodology, analysis of HRV and manuscript writing and review. Ankur Bhoot contributed to carry out the intervention, data collection, data analysis and manuscript writing.

Data Availability

Data of the research will be submitted during the review process, prior to final acceptance.

Informed Consent

Written informed consent was obtained from all individual participants included in the study.

Statement of Ethics

The study was conducted after obtaining approval from the Institutional Ethics Committee (IEC/BU/141/Faculty/18/279/2022 dated 28 November 2022).