122 CMU J. Nat. Sci. (2019) Vol.
18(1)
Effects of Newly-Developed Superimposed Binaural Beat
on Anxiety in University Students in Thailand:
A Randomised Controlled Trial
Wuthichai Chairinkam1, Lakkana Thaikruea1*,
Jakkrit Klaphajone2, and Peerasak Lerttrakarnnon3
1
Department of Community Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai
50200, Thailand
2
Department of Rehabilitation Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai
50200, Thailand
3
Department of Family Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai
50200, Thailand
*Corresponding author. E-mail: lakkana.t@cmu.ac.th
https://doi.org/10.12982/CMUJNS.2019.0010
Received: July 14, 2018
Revised: October 12, 2018
Accepted: October 21, 2018
ABSTRACT
This study aimed to investigate the effects of superimposed binaural beat in reducing
anxiety among university students and to compare the effects of superimposed binaural
beat to those of receptive music listening and relaxation treatment. The 134 participants
who participated in the double-blind randomised controlled trial were randomly selected
from 539 students with anxiety. According to block randomisation, the participants were
assigned to superimposed binaural beat (n = 45), receptive music listening (n = 45), and
blank audio (Control, n = 44) groups. All three groups received general relaxation treatment
in 20-minute daily sessions over a period of 5 consecutive days. The median differences
in anxiety level were measured by the self-administered State-Trait Anxiety Inventory
form-Y before and after treatment for the superimposed binaural beat, music listening,
and control groups at -20.00, -16.00, and -15.00, respectively. The differences between the
superimposed binaural beat group and the control (P = 0.04) and music listening (P =
0.02) groups were statistically significant. Anxiety levels were effectively reduced in 100%
of participants in the superimposed binaural beat group, which was higher than the rate in
the control group (84.09%: P < 0.01). Superimposed binaural beat-based interventions may
reduce anxiety in university students more effectively than the music listening and general
relaxation methods. The research findings are potentially beneficial for policymakers and
for developing interventions aimed at reducing anxiety in university students.
Keywords: Anxiety, Student, Music listening, Superimposed binaural beat, Relaxation,
Randomised controlled trial, Effect
CMU J. Nat. Sci. (2019) Vol. 18(1) 123
INTRODUCTION
Anxiety problems in university students have been increasing due to academic pressure
such as graduation expectation, academic achievement and financial problems (Saipanich,
2003; Vaez et al., 2006; Shamsuddin et al., 2013; Yusoff et al., 2013). Study in the United
States found 12.00% of students to have experienced anxiety issues in the previous year. Over
50% of university students reported feeling hopeless and overwhelming anxiety over the past
12 months (Regehr et al., 2013). In Egypt, medical students have indicated that anxiety has
great impact on well-being in terms of studying for and participating in examinations (Yusoff
et al., 2013). These negative effects bring concern physical and mental problems as the data
claimed by the health care centre of each university, where increasing numbers of students are
requesting services (Alzahem et al., 2011; Galbraith and Brown, 2011). Moreover, 11.40%
of university students were found to require psychological help from university counselling
centres, and this number is likely to increase (Grasgreen, 2012). Approximately 40.00% of
university students have stated that their mental health problems required psychological help
beginning with anxiety, which is one of the main causes of mental health problems. Anxiety is
recognised by medical professionals as a causal factor of mental health problems (Grasgreen,
2011). In Thailand, anxiety has a negative impact on the academic performance and emotions
of medical students (Saipanich, 2003).
Common anxiety treatments include medication, which is associated with both physical
and economic short- and long-term burdens (Department of Mental Health, 2013). Anxiety-
relief medication is commonly used to help reduce anxiety. Other treatments such as muscle
relaxation, listening to music, and psychotherapy, which requires specialist guidance, are
available, but might be inconvenient to access. One study indicated that music was able to
reduce anxiety (Shamsuddin et al., 2013) and there has been an evolution in the application of
music with a binaural beat.
Binaural beat arises from the interaction of bilateral input at higher levels of the
ascending auditory pathway (Tobias, 1963; Rutschmann and Rubinstein, 1965). The
mechanism of action is two-way with effects on the limbic system, which regulates mood,
and on brainwave entrainment. Binaural beat is reportedly generated within the brain. The
superior olivary complex is believed to be the first nucleus to receive auditory information
from both sides of the ears and binaurally activated phase-sensitive neurons are also found in
the inferior colliculus (Spitzer and Semple, 1998; Schwarz and Taylor, 2005). The fluctuation
in frequency equals the difference in the two pure tones presented. However, a classic study
reported that the maximum difference in two tones that humans can perceive as a beat is 35 Hz;
otherwise, two separate pure tones are perceived instead (Oster, 1973).
Listening to 7–10 Hz binaural beats may be beneficial in reducing mild anxiety (Le
Scouarnec et al., 2001; Wahbeh et al., 2007) and improving self-reported relaxation (McConnell
et al., 2014). For clinical interventions, binaural beat has the potential of decreasing acute
preoperative anxiety in patients undergoing general surgery (Padmanabhan et al., 2005) and
reducing anxiety in moderately-anxious patients in the emergency department by 10–15%
(Weiland et al., 2011). Binaural beat embedded in music listening may have benefits in music
interventions alone by decreasing anxiety in patients undergoing operative cataract surgery
(Wiwatwongwana et al., 2016) and may be useful in reducing preoperative anxiety in dental
124 CMU J. Nat. Sci. (2019) Vol. 18(1)
surgery (Isik et al., 2017). However, another study found that binaural beat showed positive
effects on anxiety among anxious populations, but the difference was statistically insignificant
(Le Scouarnec et al., 2001).
Superimposed binaural beat is a new binaural beat technique in which additional
binaural beats are synthesised on the basis of frequency shifting of the sound waves from
each traditional Thai musical instrument, except for drum sounds (due to their extremely low
frequency), in addition to the original binaural beats created by the standard method of pure-
tone sine wave-frequency differentiation. It is expected that superimposed binaural beat’s
quality and efficiency will be better than that of traditional binaural beat. Currently, traditional
binaural beats are used to reduce anxiety in patients in clinical trials, but none of these trials
have employed superimposed binaural beats.
This study aimed to investigate the effects of superimposed binaural beats on reducing
anxiety among university students and to compare the effects of superimposed binaural beat
to the effects of music listening and relaxation treatment.
METHODS
Participants for anxiety assessment
The data collection of this research was conducted with a sample of 1,245 from among
6,480 university students based on stratification of faculty and academic year over a 4-week
period from October to November 2016. The prevalence of acute anxiety was determined
among 1,245 health-science students using the State-Trait Anxiety Inventory (STAI) form Y-I
(state anxiety) with a cut-off score of 40 or higher (Kennedy et al., 2001). After drawing lots,
a random sequence of numbers was computer generated and used in each stratum of simple
random sampling. Overall, 539 of 1,245 students had anxiety scores of 40 or higher (eligible
for the randomised control trial (RCT)).
Participants for the RCT
No student had a history of epilepsy, severe heart disease, or depressive symptoms
(which were the exclusion criteria applied before sampling for the RCT) and 134 of 539
students were randomly selected (a random sequence of numbers was computer generated)
to participate in the double-blind RCT (neither the researcher nor the participants knew what
treatment was received). According to block randomisation, the participants were assigned
to one of three of the following treatment groups: superimposed binaural beat (45 students),
music listening (45 students), and blank audio (44 students). All three groups received general
relaxation treatment, which involved resting while sitting in a comfortable chair in a room at a
pleasant temperature and wearing stereo headphones; this treatment is basic therapy received
by everyone and prevents confounders.
The superimposed binaural beat, music listening, and control groups listened to Thai
Lanna music with superimposed binaural beat tones (with 10 Hz difference), Thai Lanna music
without superimposed binaural beat, and blank audio, respectively. They received 20-minute
daily treatments for 5 consecutive days. The participants were excluded if any complications
CMU J. Nat. Sci. (2019) Vol. 18(1) 125
arose, including anxiety events or other treatments. Anxiety levels were measured by the self-
administered STAI Form-Y (STAI-S) before and after treatment. The STAI-S is a 20-item self-
reported measure of state or current anxiety; all items were rated on a 4-point scale. Internal
consistency coefficients for the scale range from 0.86 to 0.95; test-retest reliability coefficients
range from 0.65 to 0.75 over a 2-month interval (Spielberger et al., 1983; Julian, 2011). The
researchers prevented the interference of time-dependent confounders (alcohol use, receipt of
other treatments, and use of anti-anxiety medication) and major confounders (physical illness
or tragic events causing anxiety) by notifying all participants at the recruitment stage and
monitoring using a daily questionnaire.
Superimposed binaural beat Creation
The superimposed binaural beat innovation in the present study used Thai Lanna
music, which is familiar to students in northern Thailand. Additional binaural beats were
synthesised on the basis of frequency shifting of the sound waves from each traditional Thai
musical instrument, except the drum sounds (due to their extremely low frequency), apart
from the original binaural beat, which was created by the standard method of pure-tone sine
wave frequency differentiation via a self-hypnosis and relaxation machine (SHARM, Cyber
Team Ltd., USA) (Version 2.4). The continuous sounds, namely, strings and organs, were also
arranged to be inserted into all songs in order to render continuous the frequency difference
between the ears with the least interruption between the songs. All eligible tracks of each
musical instrument were set to produce 10-Hz differences between one ear with a lower
carrier frequency and the other with a higher carrier frequency. The therapeutic frequency of
10 Hz was sustained for at least 20 minutes to ensure sufficient time to entrain the brainwaves
at the alpha level (Chiang Mai University copyright on the synthesis of superimposed binaural
beats).
Statistical analysis
Descriptive analysis included frequency, percentage and mean. Univariate analysis
included Fisher’s exact test and the chi-squared and and Kruskal-Wallis tests, depending on
the data distribution. A P-value of below 0.05 was considered statistically significant. Data
management and analyses were performed by using Epi Info for Windows (Version 3.5.4;
Centers for Disease Control and Prevention, Atlanta, GA) and STATA version 11 (Statacorp
LP. College Station, TX).
Ethical consideration
All methods were carried out in accordance with relevant guidelines and regulations.
All experimental protocols were approved by the Ethics Committee of the Faculty of
Medicine, Chiang Mai University, and cooperation was received in collecting information
from the School of Health Science, University of Phayao, (Study Code: COM-2559-03951/
Research ID: 3951 Ethics Approval Number 319/2016). Informed consent was obtained from
all participants.
126 CMU J. Nat. Sci. (2019) Vol. 18(1)
RESULTS
Baseline characteristics
One hundred and thirty-four students with anxiety were enrolled in the study. The
participants were subsequently assigned to the superimposed binaural beat, music listening,
and control groups with 45, 45, and 44 students with anxiety in each group, respectively.
Most participants were first-year female students (Table 1). The participants were comparable
in terms of demographic characteristics (Table 1). The median trait anxiety scores of the
superimposed binaural beat, music listening, and control groups were 43.00 (range: 34.00 to
69.00), 43.00 (range: 35.00 to 62.00), and 43.50 (range: 32.00 to 64.00), respectively.
Table 1. Baseline characteristics of the participants by treatment group.
Group*
Variables SBB ML Control
n = 45 n = 45 n = 44
Sex n (%)
Male 6 (13.33) 6 (13.33) 8 (18.18)
Female 39 (86.67) 39 (86.67) 36 (81.82)
Year
1 17 (37.78) 21 (46.67) 18 (40.91)
2 15 (33.33) 11 (24.44) 10 (22.73)
3 12 (26.67) 12 (26.67) 16 (36.36)
4 1 (2.22) 1 (2.22) 0 (0.00)
Faculty n (%)
Medical 27 (60.00) 26 (57.77) 26 (59.09)
Pharmaceutical 2 (4.44) 3 (6.67) 4 (9.09)
Nursing 4 (8.89) 4 (8.89) 3 (6.82)
Medical Science 2 (4.44) 3 (6.67) 3 (6.82)
Allied Health Science 10 (22.23) 9 (20.00) 8 (18.18)
Note: SBB = Superimposed Binaural Beat; ML = Busic Listening; Control = Blank audio.
Effects of treatment on anxiety levels
During the treatment period, there were no reports of alcohol use, receipt of other
treatments or anti-anxiety medication, physical illness, or tragic events. The median difference
in the STAI-S score between after and before treatments of the superimposed binaural beat,
music listening, and control groups was -20.00, -16.00, and -15.00, respectively. When
comparing the median differences among the groups, the superimposed binaural beat group
versus the control group and the superimposed binaural beat group versus the music listening
group had statistically significantly different scores (Table 2).
CMU J. Nat. Sci. (2019) Vol. 18(1) 127
Table 2. Anxiety levels among participants by treatment group.
Different STAI-S scores*
Groups P-value
median (range)
SBB -20.00 (-3.00 to -40.00) SBB versus ML: 0.02**
ML -16.00 (1.00 to -32.00) ML versus Control: 0.81
Control -15.00 (0 to-50.00) Control versus SBB: 0.04**
Note: SBB = Superimposed Binaural Beat; ML = Music Listening; Control = Blank audio; * Different median
STAI-S pre- and post-test scores; ** Statistically significant difference using Kruskal-Walis test.
Anxiety level rates reached by treatments
The students were considered to have acute anxiety when their anxiety scores were
40 points or higher. Thus, the participants who had anxiety scores lower than 40 points
after treatment were considered as normal. All participants (100.00%) in the superimposed
binaural beat group, 43 participants (95.56%) in the music listening group, and 37 participants
(84.09%) in the control group experienced reduced anxiety at the end of the 5-day treatment
period, (see Table 3).
Table 3. Comparison of anxiety normal rates after completed treatment in the SBB, ML, and
control Groups.
Groups n Normal P-value*
n (%)
SBB 45 45 (100.00) 0.045
ML 45 43 (95.56)
Control 44 37 (84.09)
Note: SBB = Superimposed Binaural Beat; ML = Music Listening; Control = Blank audio; * Statistical
significance by Kruskal-Wallis test.
DISCUSSION
Binaural beat has been used to reduce anxiety levels in numerous studies (Padmanabhan
et al., 2005; Weiland et al., 2011; Wiwatwongwana et al., 2016; Isik et al., 2017), yielding
both effective and ineffective results (Le Scouarnec et al., 2001). No previous study has used
binaural beat with music by shifting the frequency of the sound of each instrument, using a 10-
Hz difference between the left and right spectrums with pure binaural beat tones on one track.
In the present study, combining the additional superimposed binaural beat innovation with
the original binaural beat was expected to enhance the power of brainwave entrainment in
participants who listened to this music continuously. The results revealed that all participants
in the superimposed binaural beat group experienced reduced anxiety, whereas fewer
participants improved in the other two groups. The STAI-S scores decreased dramatically in
the superimposed binaural beat group (median -20.00), and the difference was statistically
128 CMU J. Nat. Sci. (2019) Vol. 18(1)
significant compared to the control group scores. At the same time, the difference in STAI-S
scores between the music listening and the control groups was not statistically significant. The
reasons proposed for the effects of music listening include music composition passing into the
nervous system, neurotransmitters and limbic system resulting in both physical and emotional
changes (Weiland et al., 2011) including parasympathetic nervous-system activation such as
slowing the heart rate, dilating blood vessels, and lowering blood pressure (Wahbeh, et al.,
2007). The alpha wavelength reflects the relaxation state.
Original binaural beat produced by the machine mentioned in previous study, was
also used in this study to investigate the anxiolytic effects of binaural beat among patients
undergoing cataract operations. The patients in the music listening and binaural beat groups
showed significantly lower STAI-S scores compared with the control group. However, the
difference between the music listening and superimposed binaural beat groups was statistically
insignificant. The mean STAI-S score of the music listening group was -7.00 and that of the
superimposed binaural beat group was -9.00 (Wiwatwongwana et al., 2016). Although the
findings of the present study indicated that the superimposed binaural beat group showed higher
different scores was believed to enhance the power of brainwave entrainment. There are some
studies used superimposed binaural beat to reduce anxiety in some patients (Padmanabhan
et al., 2005; Wiwatwongwana et al., 2016). However there is no study in university student
before, the result of this study will be useful for decreasing anxiety in students population.
The limitation of this study might be that the study explored anxiety among a subgroup
of students studying in the field of health science with high anxiety. Therefore, it may not
be appropriate to generalise the findings to other populations. The advantages of this study
were the research design, large sample size, and double-blind methodology. The study was an
RCT with time-dependent confounder control to provide immediate interventions in the least
amount of time for effectively reducing anxiety levels. Thus, we contest that these dependent
confounders had no effect on the anxiety levels. The participants were selected by simple
random sampling to ensure highly homogenous characteristics. The RCT was double-blind to
prevent selection and information biases. The major confounding variables were monitored
daily during the study period. It is believed that the results of the experiments were due to the
power of the superimposed binaural beat.
The findings of this study are potentially useful for policymakers and for developing
interventions aimed at reducing anxiety in university students by tailoring the methodology to
an adolescent context. Superimposed binaural beat-based interventions may reduce anxiety-
relief medication use, as well as the cost and side effects of medical treatment. This type of
intervention can also be conducted in large numbers of target groups in settings with few
student-affair officers, as is the case in nearly all universities in developing countries. It
is worth exploring the possibility of using superimposed binaural beat paradigms in other
population groups.
In conclusion, the findings of this double-blind RCT illustrate that superimposed
binaural beat-based interventions may reduce anxiety in university students more effectively
than the music listening and general-relaxation methods. These findings will potentially
contribute to inexpensive and safe treatment options to address high demands in university
settings.
CMU J. Nat. Sci. (2019) Vol. 18(1) 129
ACKNOWLEDGEMENT
The researchers would like to express sincere gratitude to the School of Health Science,
University of Phayao for supporting the study. We would also like to thank the students for
participating in the study.
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