One of the most popular misconception about "OM" is that it is religious. On the contrary, it is the most universal syllable because it neither refers to any particular religion nor God. There have been several theories behind the OM mantra with the most popular explanation being that it was the cosmic sound which initiated the creation of universe (big bang theory). But that alone would not have been sufficient to turn it into a regular practice in Indian culture.
As with most of the traditional practices followed in India, this also has a scientific and practical explanation (based on the physics of sound, vibrations & resonance) with some long term benefit and we shall find out what it really is.
What is mantra? In its most rudimentary form, a mantra is made of syllables which exert their influence by means of sound (vibrations). As one would have personally experienced, different syllables have different vibration patterns which affect different parts of the body. Each syllable resonates with certain organ or part of the body.
For example, by chanting "aaaaaaa", one can feel the sensation and hence resonance of nervous system in the stomach and chest region. Chanting "ooooo" creates sensations in throat & chest region and resonates with them. Similarly, chanting/humming "mmmm" resonates with the nasal cavity as well as skull/brain region.
What happens when we concatenate (join together) the above syllables into one mantra? We get the AUM mantra which when chanted sequentially activates the stomach, spinal cord, throat, nasal and brain regions. The energy moves from the abdomen all the way up to the brain, thereby channelizing energy and activating the spinal cord & brain.
Following is an excerpt from a research paper which shows the waveform of A-U-M mantra made up of 3 syllables.
One of the most popular claims made by Yogis is that chanting Om mantra improves our concentration, gives peace and steadiness to our mind, reduces mental stress and clears all worldly thoughts. Although those who practice it regularly would have experienced it first hand and affirm the same, scientists were curious to find out more about it and verify such claims with the help of science & technology.
Few years ago, scientists conducted an experiment in which participants who had never chanted Om mantra were asked to chant it for few minutes and each of their chants were recorded. The time frequency analysis of it showed irregular waveforms which indicated unsteadiness in the mind. They were asked to chant the mantra on a regular basis and after few days, the experiment was repeated. The time-frequency analysis this time had some startling revelations. The waveforms were improved with regular spacing, had almost perfect symmetry and harmony. Not only had these participants witnessed dramatic improvements in focus, concentration & steadiness, but found themselves to be in peace, witnessed reduction in mental stress & could remain calm all the time.
In another such instance, scientists conducted experiments to study the effect of Om mantra on nervous system through repeated practice. Using sophisticated software tools, mathematical transforms were applied to raw samples of the chantings and similar results (improvements in focus concentration, steadiness, peace, reduction in stress etc) were observed. Research paper: http://paper.ijcsns.org/07_book/200901/20090151.pdf
In another experiment, scientists analyzed functional Magnetic Resonance Imaging scans (f-MRI scans) before & after Om mantra chanting and concluded that regular chanting of Om mantra can treat depression & epilepsy as well.
Hence, based on scientific experiments & research studies, we can now confirm the age old claims made by Yogis that chanting Om mantra reduces mental stress, cures depression, improves focus & concentration, calms the mind and leads to better well-being, peace & happiness.