The Sanskrit word nada means ‘flow’; in the context of this practice it means ‘flow of consciousness in the form of the sound Aum’. The Sanskrit word sanchalana means ‘rotation’ or ‘conduction’. The English translation is therefore ‘the rotation (or conduction) of sound consciousness’.
This kriya is the first of a group of three kriyas – nada sanchalana, pawan sanchalana and shabda sanchalana – which follow each other in succession. They progressively induce sensitivity to the psychic pathways through the chakras. Nada sanchalana prepares one for the subsequent kriyas. It removes blockages in the flow of prana through the arohan and the awarohan. From this kriya onwards there should be a gradual increase in subtle perception and one-pointedness of mind.
This kriya and the following four kriyas utilize a very simple mudra called unmani mudra. The word unmani literally means ‘no mind’, ‘no thinking’. Therefore, unmani mudra can be called ‘the attitude of thoughtlessness’ or ‘the attitude of meditation’.
Physically, the mudra is very easy to perform. In kriya yoga it is done as follows: Eyes open wide, but without strain. Awareness at the bindu. As your awareness descends through the chakras – ajna, vishuddhi, anahata, manipura, swadhisthana to mooladhara – the eyes should slowly close. Though the eyes remain open, your attention should be on the chakras and the descending awarohan psychic passage . . . your eyes are open, but you should be looking inside.
The eyes can be completely closed or slightly open when your awareness reaches mooladhara chakra. Choose that which you like best through experience. When you do this mudra do not try too hard; let it happen.
The practice is done more mentally than physically; that is, though the eyelids are slowly closed, the important thing is to feel the process mentally. Though the eyes are open they should not perceive anything outside. This is unmani mudra.
The state of unmani arises during meditation. Though one may be acting in the world there is a state of thoughtlessness. This is called unmani avastha (the state of no thought). The mind functions but without the hindrance of conflicting thoughts and analysis. One is conscious and the mind functions, but it seems to be nowhere. In this state, the eyes perceive, but one does not see. This is unmani.
The state of unmani is widely mentioned in the traditional yogic-tantric scriptures. The Hatha Yoga Pradipika states: “Without support for the mind, one should become thougbtless; then one will remain like a space which is both inside and outside ajar.” (v. 4:50) This is the state of meditation – unmani.
“Whatever there is in the world, animate and inanimate, is only the scenery of the mind. When the mind achieves a state of unmani, then ignorance and duality cease.” (v. 4:61) Unmani implies that state which is beyond thought – meditation. It is a state where all attachment to the world of objects is dispelled. The aim of kriya yoga is to bring about unmani. Unmani mudra is a simple technique that helps to induce the experience.