“Aum (Om)” is the one eternal syllable of which all that exists is but the development. The past, the present, and the future are all included in this one sound, and all that exists beyond the three forms of time is also implied in it”. Although Om symbolizes the most profound concepts of universal creation including the three stages of existence (birth, life and death), it is in use daily. The devout begin their day, work, prayers or a journey by uttering Om, the symbol is enshrined in every Hindu temple and it is often found at the head of letters and at the beginning of important documents. Many wear the sign of Om as a pendant, and it is the first syllable of the sacred mantra “Om mani padme hum”.
The sound of OM encompasses all words, all sounds in human language
OM is a matrix of all sounds, when in its diversified form gives rise to all words used in language.
Linguistically, all audible sounds are produced in the space within the mouth beginning at the root of the tongue and ending at the lips. The throat sound is A, and M is the lip sound; and the sound U represents the rolling forward of speech articulation which starts at the root of the tongue, continuing until it ends in the lips.
To pronounce OM correctly, remember, the sound vibration is pronounced “oom” as in home.
In Sanskrit, the sound “O” is a diphthong spelled “AU”. A diphthong is the blending of two vowel sounds where both are normally heard and make a gliding sound. As a result, the difference between OM and AUM is simply one of transliteration.
A – is the waking state
U – is the dream state
M – is the state of deep sleep
At the end of AUM is a pause, a silence. This represents the state known as Turiya, or Infinite Consciousness
The symbol OM visually consists of three curves, one semicircle, and a dot.
The large bottom curve symbolizes the waking state, A.
The middle curve signifies the dream state, U.
The upper curve denotes the state of deep sleep, M.
The dot signifies the fourth state of consciousness, Turiya.
The semi circle at the top represents Maya and separates the dot from the other three curves. It signals to us that it is the illusion of Maya that is an obstacle to realization of the Highest.
The physical form of Lord Ganesha is said to be that of OM. The upper curve, of OM, is identified with the head or the face of Ganesh. The Lower curve his belly. The twisted curve, on the right side of OM is the trunk.