http://www.swamij.co m Meditation on Soham mantra is a central mantra practice of Yoga Meditation. Soham is a universal mantra as it relates to the breath, and everybody breaths. SoHum is a Sanskrit word that means "I am that," or "I am that I am."
The pinnacle of the wisdom and practices of the ancient sages is contained in the terse twelve verses of the Mandukya Upanishad, which outlines the philosophy and practices of the OM mantra (written as either AUM or OM). The three stages plus the fourth of Om mantra are central to Yoga Meditation, Advaita Vedanta, and Samaya Sri Vidya Tantra.
From:
http://www.swamij .com/om.htm
