Om or Aum is of paramount importance in Hinduism. This symbol is a sacred syllable representing Brahman — omnipotent, omnipresent, and the source of all manifest existence in Hinduism. The symbol is necessary because Brahman, in itself, is incomprehensible. Om, therefore, represents both the unmanifest and manifest aspects of God.
The vibration produced by chanting Om corresponds to the original vibration that first arose at the time of creation. The sound of Om runs through Prana or breath. Om also represents the four states of the Supreme Being. The three sounds in Om (AUM) represent the four states of waking, dream, deep sleep, and the silence after the sound
1. The waking state is represented by the sound "A"
2. The dream state is between waking and deep sleep, and is represented by the letter "U" which lies between the "A" and "M".
3. The last state of consciousness is the deep sleep state and is represented by "M" like a humming sound. This closes the pronunciation of Om just as deep sleep is the final stage of the mind at rest.
4. When Om is recited in succession, the period of silence between two successive Oms represents the "fourth state" of perfect bliss when the individual self recognizes his identity with the supreme.
Just as the sound of Om represents the four states of the Supreme Being, the symbol Om written in Sanskrit also represents everything.
1. The material world of the waking state is symbolized by the large lower curve.
2. The deep sleep state is represented by the upper left curve.
3. The dream state, lying between the waking state below and the deep sleep state above, emanates from the confluence of the two. The point and semicircle are separate from the rest and rule the whole.
4. The point represents the state of absolute consciousness. The open semicircle symbolizes the infinite and the fact that the meaning of the point can not be grasped if one limits oneself to finite thinking.
Although Om symbolizes the most profound concepts of Hindu belief, it is in use daily. The Hindus begin their day or any work or a journey by uttering Om. The sacred symbol is often found at the head of letters, at the beginning of examination papers and so on. Many Hindus, as an expression of spiritual perfection, wear the sign of Om as a pendant. This symbol is enshrined in every Hindu temple premise or in some form or another on family shrines.
The syllable Om is initiated into the life of a Hindu right at the time of birth as a symbol of piety. The newborn is ritually cleaned and the sacred syllable is written with honey on the baby’s tongue.
Om is also a popular symbol used in body art and tattoos.
Everything in the universe has a vibration and every vibration has a corresponding sound. Each atom, molecule, cell, object, group of objects, even the entire universe, has its own collection of vibrations and unique sound. The chanting of Om drives away worldly thoughts, removes distraction and infuses new vigor in the body. For more information on chanting Om and chanting in general, read here.