Yoga practitioners chant "OM" during a satsang at Yoga http://www.yoga-vidya.de Vidya Ashram Bad Meinberg. Although Om is to be found in each upanishad, at least as part of the opening and closing mantras of blessing, eight of them have sections dealing with Om Itself. In the Brihadaranyaka Upanishad is written: "Om is Brahman, the Primeval Being. This is the Veda which the knowers of Brahman know; through it one knows what is to be known."
Om is Divinity Itself. This is an incredible truth. To fill the mind and consciousness with Om is to divinize ourself, to evoke that eternal Self which is our real being.
Everything that exists is a manifestation of God. So lest we mistakenly decide that Om is divine because it-like everything else-only symbolizes the Divine or is a part or reflection of the Divine, the upanishad continues, telling us that Om is "the Primeval Being." Om is not a permutation, extension, or evolute of Brahman; It is Brahman in Its absolute, primeval state. Om does not lead us to Brahman, It IS Brahman. We need only realize that, and then we shall have attained Self-realization. For Om is our very Self, since Brahman is our Self.
Those who know Brahman do not bother with the ritualistic hymns of the Vedas to obtain their desires, but chant only Om to obtain fulfillment of their desires-especially the desire for divine knowledge. For "through It one knows what is to be known." "Veda" can mean knowledge or wisdom when found in the scriptures, so we can also consider this statement to mean that Om is the knowledge and wisdom of those who know God-since it is God. Om is that Ishwara of whom Patanjali said: "In Him is the seed of omniscience." Sivananda wrote: "All things are named by the sounds and all sounds merge in Omkara. All Languages and words ending in a single sound - "Om".
The hum of bees and the sweet song of nightingale, the seven musical notes, the sound of the mridanga and the drum, the lute and the flute, the roar of the lions, the song of the lover, the neighing of the horses, the hissing of the cobra, the groans of sick, the crying of babies, the clapping of the audience if the speaker keeps his speech - all this is nothing more than emanations from Omkara.
The sound that comes from the flow of the Ganges, the sound in the distance and the noise and bustle of a market, the sound that arises when the flywheel of a machine is set in motion, the sound of rain - all this is only just Om.
Om is the basis of all sounds. Om consists of three letters, A, U and M. A, U and M cover the whole gamut.
The larynx and the palate are the sounding boards. If one expresses A, no part of the tongue or palate is touched. If you pronounce U, the sound rolls from the beginning to the end of the soundboard in the mouth.
M is the last sound that is produced by closing the two lips. Therefore, all sounds are combined in Om. All languages are based on Om." - find more mantras like this at http://www.yoga-vidya.de/de/service/blog/category/podcast/mantra/ Om Shanti Om - yours Omkara