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Impact of Himalayan Singing Bowls Meditation Session on Mood and Heart Rate Variability
Saharsh Panchal1, Fariburz Irani2, Gunjan Y Trivedi3,*
1Public Health Specialist, Intern, Society for Energy & Emotions, Wellness Space, Ahmedabad, India
2Psychology Major, School of Liberal Studies, PDPU and Intern, Society for Energy & Emotions, Wellness Space,
3Co-founder, Society for Energy & Emotions, Wellness Space, Ahmedabad, India
Introduction: Scientific evidence has established the benefits of meditation and sound vibrations on emotional
and physiological health.
Aim of the Study: The study explored changes in mood and Heart Rate Variability (HRV) after HSB Sound Bath
Meditation on healthy individuals. The objectives of the study were to understand if a 40-minute-long seated
HSB Sound Bath Meditation results in changes (a) in mood measured via Positive And Negative Affect Scale
(PANAS) and Abbreviated Profile of Mood States (POMS) Survey and (b) in physiological parameters, as
measured by HRV.
Methods: The psychological parameters were measured with PANAS (N=77) and Abbreviated POMS, (N=17).
The physiology was measured with HRV parameters such as Heart Rate (HR), Stress Index (SI) and Root Mean
Square of Standard Deviation (RMSSD) using the EmWave Pro device (N=15). HRV data analysis was conducted
with Kubios HRV Premium and analyzed using a paired T-Test.
Results: All the subjects after meditation showed improvement in Positive Affect (PA) and a reduction in
Negative Affect (NA). The HRV parameters showed a trend showing overall relaxation with a significant
reduction in HR, SI and an increase in RMSSD. Consistent with changes in positive, negative mood and HRV, all
the participants showed a reduction in tension, anger, fatigue, depression and confusion and improvement in
esteem related affect and vigor.
Conclusion: The findings show that seated HSB Sound Bath Meditation session has a positive impact on mood-
related measures and physiology. Future work in this area could explore comparison with a control group and a
longer study duration comprising multiple sessions.
INTERNATIONAL JOURNAL OF PSYCHOTHERAPY PRACTICE AND RESEARCH
ISSN NO: 2576-612X
Corresponding author: Gunjan Y Trivedi, Co-founder, Society for Energy & Emotions, Wellness Space,
Ahmedabad, India, Email: firstname.lastname@example.org
Keywords: Singing Bowl, Himalayan Singing Bowls (HSB), Meditation, Sound Bath Meditation, Heart Rate
Variability (HRV), Stress, Mood, Emotions, Sound Healing
Received: Feb 15, 2020 Accepted: Mar 13, 2020 Published: Mar 23, 2020
Editor: Elbaih zico, Suez Canal University, Ismailia, Egypt.
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Scientific evidence has demonstrated the
negative impact of emotional stress on the mind and the
body [1, 2]. Stress doesn’t just impact the nervous
system and endocrine system but also results in the
impairment of the immune system, cognitive function
and an increased risk for chronic disease [3, 4]. One
pathway impacted by stress is the autonomic nervous
system, specifically, increased activity of the sympathetic
nervous system (fight-or-flight) and decreased
activity of the parasympathetic nervous system
(rest-digest) [5, 6]. Meditation, in general, has
demonstrated a significant positive impact on the
nervous system, i.e. parasympathetic nervous system,
thereby, reducing overall stress . Studies of the
meditation practices (especially, mindfulness-based
stress relaxation), Yoga Nidra (A form of Yogic
relaxation), and singing bowl meditation show a
significant impact on the mood and overall well-being,
with improved physiological homeostasis and reduction
in anxiety and stress [8, 9, 10, 11, 16, 13].
Many ancient cultures use sound as part of
prayers, rituals, meditative practices or other activities.
This includes the use of instruments such as Gongs,
Singing Bowls, Bells, Didgeridoo or human voice in the
form of mantra or just simple vibrations as in case of
Yogic practice of Bhramari Pranayama. Research in the
area of singing bowls has also reported a positive
impact on the psychological and physiological
parameters [12, 13]. The physics of Singing Bowls and
Gongs have been reported in various papers to
understand the mechanism involved [14, 15]. There is
an opportunity to enhance the understanding of the
impact of singing bowls on the mind and the body.
Review of literature identified the opportunity to study
the mind-body impact of a seated meditation session
with Himalayan Singing Bowls. Earlier studies have
either focused only on the psychological measurements
or worked with subjects in supine positions and even
compared with a control group (silence) [16, 13]. Most
of the studies involved 60 minutes long sessions with
only one study measuring the impact of a short duration
session of around 20 mins . The psychological
impact of the previous research indicates some
inconsistency with one study showing a decrease in both
positive affect and negative affect using PANAS while
demonstrating a reduction in heart rate and blood
pressure and another has shown a reduction in Positive
Affect while combining sound with relaxation
though both studies show a reduction in negative
moods [13, 18]. This indicates an opportunity to
understand the mood changes (including the impact on
specific moods) along with physiological changes during
a single session of HSB seated meditation [17, 18].
Based on the outcome of this study, further work can
focus on the longer term measures with the addition of
the control group.
The primary objective of the study was to (a)
validate that seated single 40 mins long HSB Sound Bath
Meditation session has a statistically significant impact
on the mood (positive affect and negative affect, as
measured by PANAS survey) and (b) physiology (as
measured by HRV parameters such as HR, RMSSD, and
SI). The secondary objective was to do a preliminary
assessment of specific changes in positive and negative
affect parameters (as measured by POMS). The study
methodology is captured in Figure 1.
Materials and Methods
Participants and Design
This study was conducted across two months at
a Wellness Center where free group meditation with
Himalayan Singing Bowls is offered twice a month to
anyone who is interested. The participants who
volunteered to join the study signed informed consent.
Ethics committee approval was not required since the
free meditation is open to the public and the
interventions were non-invasive, consistent with earlier
work in this area [13, 18]. A room with good soundproof
interiors was used while maintaining 25 Degree
Centigrade temperature (Figure 2). This ensured the
minimum impact of outside sound and a pleasant indoor
temperature. The exclusion criteria included the
presence of (a) chronic disease (b) epilepsy (c)
pacemaker in the body and (d) metal parts due to any
surgery inside the body.
Total 105 subjects signed the informed consent
form for PANAS forms, 21 subjects signed POMS form
and 20 subjects agreed to undergo the measurements of
HRV. Those who agreed for PANAS and POMS
completed the self-administered survey 5 minutes before
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and 5 minutes after the meditation and individuals who
agreed to wear the HRV device wore it throughout the
meditative practice lasting 40 minutes.
The meditation took place from sharp 7:00 PM
to 7:40 PM, twice a month and on the dates
communicated in advance. The participants were
instructed to sit in a cross-legged meditative posture on
a meditation chair that provides back support. After
completing the signed consent, the participants were
given brief instructions specifying the duration of the
meditation (exactly 40 mins) and required to focus the
attention on the sound vibrations of the singing bowl or
observe their breath - especially when their mind gets
diverted. The meditation is conducted by a trained
therapist with the use of (a) 7 handmade singing bowls
ranging from 18cm to 29cm diameter and (b) one
Ting-Sha (as shown in Figure 3) . No gongs or other
music or sound instruments were used. Participants
were instructed to do three humming sounds at the
beginning and end of the meditation and throughout the
process, they are requested to keep the eyes closed
while maintaining the attention on observation of the
sound vibrations or their own breath. No other
instructions are given. In the beginning, after the three
humming sounds, the participants were instructed to
follow the session leader’s instruction on progressive
muscle relaxation (PMR), lasting maximum 3 mins
requesting the participants to relax all body parts
starting with toes, legs and so on. For the balance of the
session, only the sound vibrations of the bowls and
Ting-Sha were used, i.e. No more verbal instructions
were provided. As mentioned earlier, the sessions ended
with three humming sounds. At the end of the session,
the participants were requested to slowly observe the
changes in the mind and the body and open the eyes
when they were comfortable. The lights in the room
were closed throughout the meditation. During the
mediation, the sound vibrations of the bowl followed a
simple pattern of maintaining a gap of about 4-5
seconds between the successive hitting of the bowl and
periodically, all the bowls were hit a bit faster to create
louder sound from all bowls together (every 8-10
minutes). The bowls were hit by a hammer and the
rimming used a wooden stick covered by leather at one
end. The entry to the room was closed throughout the
practice and air conditioning was maintained at a
constant temperature (Figure 2 shows the room). The
bowls (shown in Figure 3) were placed in one corner of
a long room with a seating capacity of 20 individuals.
Data Measurement & Analysis
The psychological parameters were captured
using PANAS and abbreviated POMS forms. The HRV
data were collected to measure physiological parameters
using the Emwave Pro device (HeartMath, LLC) with PPG
(Photoplethysmogram) ear sensor during the entire
session. The HRV data was analyzed using Kubios HRV
premium software on a Windows 10 PC. The features
available in Kubios HRV Premium software (version
3.3.0) were used to export the parameters in a. txt file
Figure 1. The study methodology
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which included Heart Rate, Stress Index and RMSSD.
Each .txt file was tabulated and analyzed using Microsoft
Excel pivot table. The data was integrated for each of
the 5 minutes of the 40 minute long sessions. Microsoft
Excel features, specifically function TTEST, were used to
do statistical analysis of the data. The analysis used
Paired T-test to compare the changes between various
intervals for each method (details are captured in the
77 out of the 105 subjects who filled up PANAS
forms properly were included in the study. 17
participants completed the abbreviated POMS forms to
assess Tension (TEN), Anger (ANG), Fatigue (FAT),
Depression (DEP), Confusion(CON), Esteem Related
Affect (ERA) and Vigor (VIG). All the forms were filled by
the participant before and after the meditation and
entered into Microsoft Excel sheet for further analysis.
15 participants completed the full HRV recording during
the meditation process to measure the physiological
parameters like heart rate, and stress index, etc.
Demographics of the subjects and the number
of subjects attended the various data collection
methods, i.e. PANAS, POMS, and HRV recorded are
captured in Table 1.
PANAS is a self-report psychometric
questionnaire that can be used across a diverse sample
group, measures two segments or moods of an
individual. Each segment has 10 terms in which the
subject can rate from 1 to 5. Eventually, we can
measure the positive and negative affect of the subject
before and after any intervention [20, 21]. PANAS has
been widely used in the areas ranging from overall
mood change in areas ranging from clinical studies
involving patients as well as in the areas involving
healthy individuals doing various activities such as
creative work . PANAS has also been used to
measure psychological changes in mood in studies
related to meditation and also singing bowls. While
PANAS provides valuable insight about the mood,
additional validation of the changes in mood via
physiological data could add more credibility to the
overall conclusion [23, 24]. The abbreviated POMS is a
simple and effective self-reported questionnaire to
understand changes in specific moods . The
expectation was to understand the specific impact on
positive and negative mood with the use of PANAS and
additionally understand the changes in specific moods
with the help of abbreviated POMS.
HRV is a beat-to-beat interval between
successive heartbeats (also known as RR or NN interval)
and indicates a physiological state. It has been used to
evaluate the impact of the singing bowl during supine
position13 17. HRV is also emerging as a meaningful
marker of autonomic nervous system imbalance, stress,
metabolic syndrome and chronic disease. For this study,
we used (a) Heart Rate (b) RMSSD (The RMSSD reflects
the beat-to-beat variance in heart rate and is the
primary time domain measure used to estimate the
vagally-mediated changes reflected in HRV) and (c)
Stress Index (The Baevsky’s stress index is a rather
widely used index of cardiovascular system stress and is
strongly linked to sympathetic nervous activity).
Together, these three physiological measures provide an
understanding of the relaxation process as compared to
heart rate alone and provide a more comprehensive
perspective about the changes in the autonomic nervous
system. Specifically, changes heart rate and stress
index could provide an indicator of the reduction in
sympathetic nervous system activity. The increase in
RMSSD denotes a pronounced parasympathetic nervous
system activity .
Pre and post meditation data of PANAS for 77
enrolled participants showed a statistically significant
increase in the positive affect (pre=33.25, post=36.26,
p<0.00) and a statistically significant reduction in the
negative affect (pre=19.92, post= 14.21, p<0.00)
The above results confirm the primary objective
(a) of the study that there is a statistically significant
reduction in negative affect and a similar increase in
Table 3 shows the key HRV parameters
captured every 5 minutes during the Seated HSB Sound
Bath Meditation for 15 individuals (Mean Age=37.20,
SD=12.69). Paired T-Test calculations between the first
(0-5 min) and the last interval (35-40 min) of the
meditation indicates a statistically significant change in
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Mean PA SD PA Mean PA SD PA p-value Mean NA SD NA Mean NA SD NA p-value
Before Before After After PA* Before Before After After NA*
77 33.25 7.42 36.26 6.80 0.00 19.92 6.68 14.21 4.08 0.00
Table 2. PANAS Change in Positive Affect and Negative Affect for all participants with * denoting statistically
significant changes (for both PA and NA).
Time Mean HR* Mean RMSSD* Mean Stress Index*
0-5 min 79.99 38.17 11.53
5-10 min 79.08 36.48 12.42
10-15 min 78.06 40.12 12.58
15-20 min 77.81 40.29 12.24
20-25 min 77.56 39.69 11.75
25-30 min 77.07 42.62 11.27
30-35 min 76.44 44.79 10.98
35-40 min 78.17 55.98 9.65
Table 3. Changes in key HRV parameters during the meditation (* denotes a statistically
significant change in the parameter during 35-40 min as compared to 0-5 min, despite
the use of PMR during 0-5 mins).
PANAS HRV POMS
n Mean Age SD n Mean Age SD n Mean Age SD
Male 36 35.53 13.78 9 35.00 13.19 8 29.25 7.83
Female 41 38.49 12.60 6 38.67 12.92 9 35.78 11.13
Total 77 37.10 13.16 15 37.20 12.69 17 32.71 10.13
Table 1. Demographics of the individuals who participated in various measurements
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(a) Heart Rate (b) RMSSD and (c) Stress index. As
captured earlier, the Baevsky’s stress index is a rather
widely used index of cardiovascular system stress
and is strongly linked to sympathetic nervous
activity . Hence, reduced Heart Rate and Stress
index indicate a statistically significant reduction in
sympathetic nervous system activity. The RMSSD
reflects the beat-to-beat variability in heart rate and is
the primary time domain measure used to estimate the
vagally-mediated changes reflected in HRV . The
trend of these key parameters is shown in Figure 4.
These results indicate (a) overall stress level increases in
the early part of the meditation and eventually begins to
reduce after about 15 mins and continues the downward
trend, consistent with other changes i.e. an increasing
trend in RMSSD (b) overall heart rate, however,
continues to reduce every 5 minute interval. From
statistical perspective, the p-value of Heart Rate, RMSSD
and Stress index show statistically significant changes
when we compare the last 5 minutes of the meditation
with the first 5 minutes. A significant increase in RMSSD
denotes a likely increase in parasympathetic tone while a
reduction in heart rate and stress index indicates a
likely decrease in the sympathetic tone of the
participants - when we compare the first 5 minutes with
the last 5 minutes. The trend (Figure 4) also validates
The above results confirm the primary objective
(b) of the study that there are statistically significant
changes in physiological i.e. HRV parameters towards
the end of the meditation as compared to the beginning.
Analysis of Abbreviated Profile Of Mood States
(POMS) questionnaire show all specific variables except
vigor show a significant difference between pre- and
post-meditation (Table 4). All the negative moods show
a statistically significant decrease while Esteem Related
Affect shows statistically significant improvement. Vigor
score showed an increase, however, it was not
statistically significant (p=0.31). A possible explanation
for why Vigor could be that while meditating, people are
likely to become increasingly relaxed. Moreover, the
intervention does not provide any guided imagery that
could cause excitement and active feeling. These could
be the reasons why we believe that Vigor may have not
The study explored the mind-body impact of a
single session of seated HSB sound bath meditation. The
results indicate significant changes i.e. reduction in
negative affect and an increase in positive affect. Unlike
the previous study, this study method has generated a
positive trend in PANAS with an increase in PA and a
decrease in NA18. It is likely that a longer duration
intervention may have contributed to the positive
impact on the mood since as shown in Figure 4, the HRV
changes during the initial 15 minutes indicate some
activation of sympathetic activation due to an increase in
stress index along with a decrease in RMSSD. However,
after the initial 15 minutes, the overall trend in HRV has
changed denoting an increase in parasympathetic
nervous system activity along with a decrease in
sympathetic activity. While this trend in HRV data does
not directly explain the changes in the mood, it still
shows a more relaxed body which may have triggered
the beneficial changes in the mood.
The findings are significant since both the mind
and the body changes are positive and demonstrate a
significant psychological and physiological benefit of
such a session. Such sessions can be very useful for
individuals keen to reduce stress and improve overall
mood. Applications could also include individuals facing
sleep disruption or an inability to relax or generalized
anxiety. Such practice, on a regular basis, could speed
up the relaxation response, known to have a profound
impact on the mind and the body5. Some creative
possibilities for applying sound bath meditation could
include pre-surgery relaxation for subjects as well as
health care professionals, individuals suffering from
depressive mood, anxiety and so on.
This study demonstrates a significant
psychological and physiological impact of a 40 min long
seated Himalayan Singing Bowls meditation, validated
not just through a questionnaire, but also using Heart
Rate Variability measures throughout the session to
understand the impact on the overall physiological
measurement of stress and autonomic nervous system.
This intervention can help in the reduction of anxiety
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Figure 4. Changes in HRV parameters. Parameters with * indicate a statistically significant change
(during 35-45 min as compared to 0-5 min). The X-axis shows the time into the meditative practice. Y-axis
shows the three parameters, i.e. HR, RMSSD (Primary, left) and Stress Index (Secondary, right)
Pre- Meditation Post- Meditation
Measures Mean SD Mean SD %
Tension 17 7.06 2.68 3.76 2.75 -47% 0.00*
Anger 17 4.88 3.43 2.12 2.34 -57% 0.00*
Fatigue 17 6.24 3.58 2.41 2.35 -61% 0.00*
Depression 17 6.82 4.45 2.47 2.83 -64% 0.00*
Confusion 17 7.82 4.42 5.12 3.41 -35% 0.00*
Esteem Related Affect 17 14.35 2.74 16.29 2.71 14% 0.01*
Vigor 17 8.00 3.37 8.41 3.00 5% 0.31
Table 4. Summary of POMS data before and after meditation. Parameters with * indicate a statistically
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and depressive mood and provide mind-body relaxation.
A more detailed study, involving a randomized
trial with a control group, would substantiate the long
term benefits of such an intervention. Future work
could explore if an individual session would be more
effective as compared to a group session and whether
such intervention would have an equal impact on
healthy individuals as compared to individuals who have
metabolic syndrome components or chronic diseases
such as hypertension or diabetes.
The authors would like to acknowledge the help
from Mr. Rajan Shah and Mrs. Dhwani Shah of Wellness
Space for data management, analysis and Ms. Rene
Shah (student volunteer) for help in administering
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