High Realms of Prana Yoga

When the air blows through small holes, its friction gives rise to specific sounds. The musical sound of a flute is also generated by the same effect. When stormy breeze flows through the bamboo-forest, it sounds like a sharp swara of a flute. When high speed winds pass through thick field of trees, their friction with the latter also produces such sounds. The nostrils in a human body are like the holes in a narrow tube - as in a flute for instance.
The in and out flow of air through these tiny holes of the nose produces typical sounds. Deep breathing at a slow pace intensifies this sound produced by the friction of the air with the nasal walls. This sound resembles that of the word 'so' during inhalation and as that of 'ham' during exhalation. These sounds are subtle and cannot be heard loudly by the ears. Nevertheless, these specific sounds can be 'perceived' through harmonizing the breaths and meditating on each breath in an otherwise silent atmosphere.
As described earlier, the practice of soaham sadhana (or hamsa yoga) involves a pranayama in which the sadhaka takes deep breathing at a slow and consistent pace and concentrates on the above mentioned sounds. The stability of meditation, strength of will power and emotional intensity of the sadhaka - in attracting the omnipresent current of divine prana and throwing away the self-obsession and weaknesses - play the major role to make it a high level pranayama sadhana. As it involves the perception (realization) of the sublime and self-generated sounds, this sadhana is equivalent to Brahm enable a great spiritual practice - ajapa japa of Gayatri.
While performing this superior Pranayama, the sadhaka should first sit quietly and experience (not just imagine) that a glowing ocean of the divine pranas is spread all around him. This is the first phase of meditation. With all his willpower he should then begin the sadhana by taking a deep breath and feeling that with the subtle sound of 'so' thy power of the supreme source of consciousness has infused deep inside in the form of the divine prana. The sadhaka should retain the breath for a while and feel that with the subtle sound of 'a' this mahaprana has been absorbed by the inner centers of the body and is illuminating and energizing the whole body, mind and the heart (emotional center). Then, while breathing out, the sadhaka should again use all his willpower to expel his entire ego, anger, lust, jealously, selfishness and other vices and infirmities along with the sound of 'ham' ….. Stopping the breath for a few seconds, he should then feel that all the discarded malign assimilation have been waned out in the surroundings and will never return to him… he should repeat this cycle several times. Continuous practice with zeal trains the sadhaka in performing this sadhana with perfection.
Initially, the sadhaka should perform this sadhana for about 5 to 10 minutes everyday. This should be preceded by a meditation (as described above) of about 15 minutes duration and followed by a contemplation phase of about the same duration. In this last phase, the sadhaka should feel that the divine power has blessed him with thy grace and that the supreme consciousness has bestowed divine qualities and potentials on him. He should concentrate upon different components and inner cores of the body and feel that each element is illuminated by absorption of the divine energy. He should also contemplate that he has devoted himself to the God and that all his sense organs, mind and the intellect are now in the hands of that Almighty.