OM, like many Sanskrit words, has various meanings. This symbol is actually
a sacred syllable representing the supreme consciousness or the absolute
the source of all existence. The syllable OM occurs even in English words
having a similar meaning, for instance, omniscience, omnipotent and omnipresent.
As the cross is to Christians, the OM is to Hindus. It is made up of three
Sanskrit letters, aa, au and ma which, when combined, make the sound AUM
or OM. It occurs in every prayer and invocation to most deities begins
with it. As the symbol of piety, OM is often found at the head of letters,
pendants, enshrined in every Hindu temple and family shrines.
Repetition of OM or AUM dissolves the mind in its divine source (Gurjar
and Ladhake, 2008; Gurjar et al., 2008).
If you chant OM several times out loud it is said to purify the atmosphere and
connect you to the universal life force of all creation vibrating at the same
wavelength. Before some decades, Yogis and meditating professional affirmed
that chanting. mantra improves our concentration, gives peace and steadiness
to our mind, reduces the mental stress and clears all worldly thoughts. Although,
its required to verify importance of mantra chanting systematically, no
schemes have demonstrated yet. In this research work, we have confirmed the
significance of OM chanting.
Chanting meditation means keeping a not-moving mind and perceiving the sound
of your own OM. Perceiving your voice means perceiving your true self or nature.
Then you and the sound are never separate, which means that you and the whole
universe are never separate. Thus, to perceive our true nature is to perceive
universal substance. With regular chanting, our sense of being centered gets
stronger and stronger (Khalsa, 2000). However, when
we do chanting meditation correctly, perceiving the sound of our own voice,
we learn that chanting meditation is not for our personal pleasure, to give
us good feeling, but to make our direction clear. At the moment of true perceiving,
there is no thought, no separation, only perceiving sound. This is the crucial
point (Andersen, 2000).
This study is a part of scientific investigations on time-frequency analysis
of acoustic generated by devine sound OM (Gurjar and Ladhake,
REVIEW OF PRIOR WORK
Since, the time of Lord Rayleigh, i.e., the beginning of the 19th century,
there has been a lot of interest in studying the effect of music on the
human system. It is only recently that interest has developed in extending
this work to Mantras also.
Stigsby et al. (1981) conducted a study on the
effect of mantra meditation on the electroencephalograms of experienced mediators.
The results were inconclusive. Seer and Raeburn 4 conducted a similar study
on the effect of meditation training on hypertension. Here also, the study showed
modest reductions in blood pressure, but the results were again inconclusive.
Telles et al. (1994) conducted experiments
on the effect of OM meditation on Middle Latency Auditory Evoked Potentials
of 18 male subjects between the ages of 25 and 45 years, 9 of who had more than
10 years of experience in OM meditation and the other 9 had no experience at
all. The results indicated that the experimental group showed an increase in
the peak amplitude of Na wave, whereas there was a significant decrease in the
control group. They extended this study in 1996, with the experimental group
meditating on OM and the control group meditating on a neutral word one. Mental
repetition of OM showed a significant decrease in skin resistance level of the
experimental group as against the control group. There was also a reduction
in the heart rate and the rate of breathing.
Takahashi et al. (1999) conducted a pilot study
on the effect of low frequency noise on human body vibration. They showed that
the low frequency noise affects the health of individuals depending on the structure
of the body. The frequency range used by them was from 20 to 50 Hz, which is
quite below the frequency of a normal human voice.
Heisnam Jina Devi et al. (2004) conducted experiments
to study signal characteristics of mantra sound patterns. They showed that OM
(A-U-M) signal has two segments, starting with O and gradually tapering off
From the point of view of intonation and the shape and the cavity of
the mouth, the sound O is in between the sounds A and U. The male voices
show 9 sub harmonics in the region of O and 2 in the region of M. In the
case of the female voices, these are 4 for O and 1 for M. Thus, it is
clearly seen that the sound pattern for O in all cases lies between those
for A and U. In the second segment, all sound patterns agree with those
recorded earlier for M.
It is thus seen that attention has so far been focused on the effect
of sound forms, hardly anything having been done on the structure of the
sound forms or mantras.
Unless one knows the sound characteristics of mantras in detail, one
will not be in a position to identify the factors, which have been found
to influence the human nerve system. It is this fact, which has motivated
the current study.
Recordings of OM chanting served as a database of this experiment. The
recordings were made in a quite room at 44.1 kHz sampling rate using a
close-talk microphone. All files were segmented manually. Male and female
speakers of age group 30 to 40 did the entire recording in evening time
after a days work before dinner by sitting in a padmasana position shown
in Fig. 1, which is best position for mediation. Recording
is done for about 10 min.
CONCEPT AND TECHNIQUE USED
Here, we give a brief introduction of the concepts and techniques utilized.
||Recording of the OM chant using a close-talk sensitive
microphone in the windows wav format
||Digitizing the analog waveforms with the help of a MATLAB using
a sampling rate of 44.1 kHz
||Start and end point detection to resize wave file
||Segmentation of complete chant into OM samples
||Spectral analysis for each OM in OM chant
The first aim is to extract the useful part from a sound file and hence
for this we start with recording OM in the Windows wav format. We use
PCM coding with 44.1 kHz sampling frequency. While, the file recording
is affected by noise and other disturbances, so, it is important to specify
some threshold and resize the file after defining the start and the end
point of actual sound.
To view the characteristics in frequency domain, we take the Fast Fourier Transform
(FFT) of the samples, between start and end samples (John
and Manolakis, 1999). In order to perform this operation we use the software
MATLAB, which has FFT as a predefined function. The results of FFT are used
to calculate power and a plot of power (in db) v/s. frequency is taken which
is Power Spectral Density (PSD). In statistical signal processing and physics
the Power Spectral Density (PSD), or Energy Spectral Density (ESD) is a positive
real function of a frequency variable associated with a stationary stochastic
process (Rabinar and Schafer, 1993) or a deterministic
function of time, which has dimensions of power per Hz, or energy per Hz. It
is often called simply the spectrum of the signal. Intuitively, the spectral
density captures the frequency content of a stochastic process and helps identify
The analysis results prove that chanting OM attains the steadiness of
mind. To avoid disturbances due to ambient noise or other sources of sound,
a professional recording was preferred.
Therefore, a professional recording of the Divine sound chanting OM was
obtained and used for further scientific investigations. During the OM
chanting, our mind focuses on the repetition of OM chanting. Moreover,
this practice helps us to reach steadiness. The frequency of the chant
signal achieves steadiness following a continuous chanting. This specifies
the attainment of the steadiness in the mind of an OM chanting person.
This provides calm and peace to the stressed mind. The mental stress of
a person gets reduced while the mind reaches steadiness. In addition,
concentration also improves. Power Spectral Density (PSD) waveform of
a single OM in an OM chant of a male and female speaker is shown below
with the data statistics using linear fitting. It is clear from PSD waveform
shown in Fig. 2-5, the sound OM contains
equal power within a fixed bandwidth at any center frequency i.e., it
resembles PSD of white noise shown in Fig. 6.
||PSD of sound OM of female speaker with slope of -0.72
for linear fitting
||PSD of sound OM of male speaker with slope of -0.76
for linear fitting
||PSD of sound OM of female speaker with slope of -0.86
for linear fitting
||PSD of sound OM of male speaker with slope of -0.65
for linear fitting
||PSD of white noise with slope of -0.0089 for linear
A flat PSD is an indication of existence of most sound frequencies in
OM. Due to this reason it is commonly used to mask other sounds. As you
gently allow the OM mantra to flow with the breath, the mind becomes calm.
When the mind becomes calm, the body relaxes and the breath becomes even
soother and slower.
That rate of speed at which the OM mantra is being repeated naturally
slows down. It is not a matter of forcing the mantra to slow, but rather,
this slowing comes quite naturally. Allow the mind to stay wide-awake
and alert, as the OM mantra and breath become naturally slower and slower.
Within minutes your mind and body begin to relax. By this analysis we
could conclude stress gets minimized after OM chant.
A MATLAB code in brief to plot a PSD of white noise is given below:
||randn (N, 1); T = 1;