Om is undoubtedly a part and parcel of Indian culture. Practically in almost all the languages Om is drawn as a sacred symbol. Om is respected by spiritual aspirants all over the world. A few decades back, Om was encircled by mystical notions and myth. But in twentieth century, due to scientific research, its universal and secular nature as well as the therapeutic significance was revealed. There are identical type of words in other cultures also viz., Shalom (Hebrew), Salaam (Arabic), Amen (Christian), and Amin (Islam).

Om is a one-word mantra and yet the most powerful mantra in Hinduism. It is the essence of all mantras. As a rule, every mantra begins with Om otherwise it is considered as incomplete. Potency of the mantras increases due to Om hence it is regarded as the king of all mantras. This is an auspicious mantra through which spiritual forces or the vibrations or the special kind of sensations in the body can be experienced. It not only gives material benefits, but the spiritual as well. Om is pronounced and written as Om, Om or even as Omkar.

Indian Tradition and Om
Mandukya Upanishad, Katha Upanishad, Varaha Upanishad, Taittariya, Bhagavad Gita, and Dnyneshwah describe Om in detail. Patanjali, the composer of Yoga sutras says "Tasya vachakah pranavah", Patanjali Yoga Sutra: 1:27. This connotes that Om is a symbol or emblem of God. It is the representative of the divine consciousness (Ishwar). So wherever there is Om, there is God. Therefore it is eternal. Om is surrounded by whatever is auspicious and virtuous. It is a sacred symbol or emblem. By reciting Om (Omkar) the realisation of the existence of Lord Brahma, the divine creator is perceived. As Om is considered as the evidence of the existence of God, Omkar sadhana is regarded as the supreme spiritual practice. Omkar sadhana is also revered in Jainism and Buddhism.

Yoga Vashishtha, a great yoga scripture says that the mind and the speed of thoughts can not be separated easily by ordinary methods. Mind and prana (force of life) are deeply connected with and controlled by each other. Different vrittis (tendencies, activities) arise in chitta that stimulate prana and therefore the mental thoughts. So if prana can be controlled, the control of mind and the thought process also follows the way. This is possible by practicing pranayama as well as Om chanting. Therefore it is better to practice pranayama first and then chant Om (Omkar japa). According to Mantra yoga, whosoever listens, sees, chants Om, will become one with the divine consciousness which is beyond wakeful, dream and sleep states of consciousness. Atharva-Shikha Upanishad right in the beginning asks "On which object we should meditate?" and gives the answer, "on Om". Therefore no yoga sadhana will be complete without Om recitation.

According to Mandukya Upanishad, Om represents past, present and future and also that exist beyond time and space. Om has no beginning or end. It is beyond the gross subtle and causal bodies because it is an expression by God. Om brings equilibrium in every aspect of human body and destroys ego, desires and suspicion.

Hatha yoga says "Pranav recitation is like nadanusandhan" (HathapradipikaW/:81-89,105,106). It increases concentration of mind and therefore can lead to dhyana and Samadhi.

During Yajna (fire worship) and Vedaddhyayan (study by chanting of Vedas), Om is chanted first so that any mistake in the technique will be compensated and there will be no obstacle in Yajna or Vedic chanting.

Formation of Om
According to Samkhya philosophy, Aakash (sky) principle was first created and then the first (primordial) vibration (shabda) was produced in the form of Om. Later on the whole universe emerged from the word Om just like different vessels are manufactured from the same earth. That is why Om is called as Shabdabrahma. This is the only mantra, which is in the form of a pure sound vibration (tone). One can experience a typical blissful and joyous condition of mind even if one listens to Om chanting, done by others. This condition is known as Brahmananda. Om is a response given by Lord Brahma to the invocation by sadhaka. Sound vibrations produced due to Om recitation would lead us to Lord Brahma. This effect of Om is due to the vibrations of divine sound (Nada). That is why it is also known as Nadabrahma Right from the ancient times, there have been different styles of writing Om. During the Vedic period it was written in the vertical form and later on it was written horizontally as it is written today. Om contains three and half matras or the potential parts. The crescent with a dot on the top of Omkar is the half matra. If we remember, the kundalini shakti (energy) is also stored in three and half coils. That is why all the mantras derive their potency from Om. Om is formed out of three alphabets, `A` `U` and `M`. A stands for Lord Brahma (creation), `U` represents Lord Vishnu (maintenance) and `M` stands for Lord Shiva (destruction). It is believed by some that Om and Lord Ganesha are same as they look similar.

Relationship of Om with Chakras
`A` of Om is connected to Muladhar (at the bottom of the spine) and Swadhishthan Gust below the umbilicus) chakras. `U` of Omkar is related to Manipur chakra just above the umbilicus. `M` affects Anahat (heart), Vishuddha (throat) and the Ajna (between the eye brows) chakras together. That is why the `N` is deliberately pronounced for longer duration to progress on the spiritual path. As we know, the chakras are the wheels of energy, providing us the energy for different bodily and mental functions. Om makes these chakras powerful, which in turn keep one energetic and enthusiastic. This indicates that by chanting Om, prana gets upward direction or in other words, kundalini can be awakened. That is why Om chanting is the superior mantra sadhana for the physical, mental and the spiritual benefits.

Scientific Research on Om
Many scientific studies have been conducted at different institutions regarding the effect of Om on the body and mind. The results have been published in various scientific journals. It has been observed that when Om is recited ten times in a low pitch, the internalized attention is produced. In simple words the attention turns inward. The number of attention fluctuations is reduced. The concentration is improved and it is well focused. Alpha rhythm is nicely synchronized and blood pressure as well as heart rate is reduced. Galvanic skin resistance is increased. In short, Om recitation is done in a lower pitch (voice) and prolonged manner, produces parasympathetic predominance and brings about calmness and peace. Typical sensations are blissful condition of mind. When Om is chanted in higher pitch, the heart rate and the muscular activity at the chin as well as the `cortical arousal` increase. EEG shows reduced alpha rhythm. In short, a sympathetic activity increases indicating a nervous excitation.

Benefits of reciting Om
When Om is recited in a low pitch the duration of Om decreases but if Om is recited in higher pitch the length of one pronunciation increases by a few seconds. Duration of its recitation also increases if Om is chanted after Kapalbhati kriya or Shauasana. Depression and anxiety have been seen reduced and a psycho-physiological relaxation increases due to twenty Om recitations done in the morning and evening for a few days. Hypertension is reduced and the sleep pattern improves by Om recitation. The emotional stability, mental peace and the balance increase as the tensions are removed. In case of children the memory and IQ has been found improved after Om recitation. Their perception power also improves. It is postulated that this may happen as the nervous system is influenced by the vibrations and resonance of Om. For these reasons, Om chanting has received a therapeutic importance.

The Process of Reciting Om
Varaha Upanishad says, "Tailadharamivacchinnam deergha ghanta ninadavat", i.e. it should be chanted very smoothly and continuously like smooth fall of oil (without interruption) like a resonance of a (Church) bell. It should be melodious. Traditionally, Om can be recited in three ways: Vaikhari, i.e., loudly, Upanshu, i.e., murmuring (as if speaking to oneself) and Manas, i.e., mentally, in the mind.

It is obvious that those who wish to keep balance in physical and mental health as well as the material gains should adopt Vaikhari technique. Those who desire the physical and material arise benefits more, should follow the Upanshu manner and those who are desirous of spiritual benefits more, should resort to Manas method. This is based on the special association of A, U and M with chakras. While practicing the recitation of Om, the practitioner should sit in Padmasana or ardha Padmasana posture or just in `crossed legs` condition in a straight, steady and relaxed motion. The eyes should be close to feel the calmness of mind.

Three rounds of Anulom-vilom pranayama should be practiced. Then with a deep breath, the Om is chanted. One can even feel its vibrations while chanting. Recitation in this way should be practiced for minimum ten times at a stretch in one sitting. There is no limit for the maximum number of recitations. After finishing the recitation (japa), the practitioner should sit quietly, visualize and meditate on it for 5-10 minutes.