FYI: http://en.wikipedia.org/wiki/Mantra
In Hindu tantra the universe is sound. The supreme (para) brings forth
existence through the Word (Shabda). Creation consists of vibrations at
various frequencies and amplitudes giving rise to the phenomena of the
world. The purest vibrations are the var.na, the imperishable letters
which are revealed to us, imperfectly as the audible sounds and visible
forms.
Var.nas are the atoms of sound. A complex symbolic association was built up between letters and the elements, gods, signs of the zodiac, parts of the body -- letters became rich in these associations. For example in the Aitrareya-aranya-Upanishad we find:
In effect each letter became a mantra and the language of the Vedas, Sanskrit, corresponds profoundly to the nature of things. Thus the Vedas come to represent reality itself. The seed syllable Aum represents the underlying unity of reality, which is Brahman.
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