Swara Vigyan

Kabir in one of his famous writings, immortalised by legendary classical singer Shri Kumar Gandharva in his “ Nirgun-Nirbhaya” bhajan, gives essence of Swara Vigyan in following words :

इंगला-पिंगला-सुखमन नाड़ी.;  त्रिवेणी पे हां नहाऊंगा || (Ingila, Pingala and Sukhman are the Channels; I Will Bathe at the Confluence of the Three Rivers)

'Nirbhay Nirgun Gun Re' sings Pt. Kumar Gandharva - YouTube

Diving deep into concepts of Swara vigyan & Hatha Yoga, one comes across the concepts of Prana and Nadis. The Prana flows through our body through wire like channels known as Nadis, which are described to be 3,50,000 in number, as per Shiva Samhita (& differently in some other texts). The purpose of Hath Yoga was to cleanse these Nadis to keep the flow of energy smooth, through physical Aasanas and Pranayam. This was a preparation for the activation of eight Chakras and ultimately the Kundalini Shakti. Awakening of Kundalini with impure Nadis is considered a recipe for disaster. Thus, Hatha Yoga uses Prana as the key to expand awareness of consciousness and realise the self. On the other hand, various other Sanatan systems of Yoga may achieve the same by purifying the intellect and developing wisdom. 

In the Upanishads, prana vayu is also called as the Apana (In breath), Samana (the out breath) and Udana (Up breath). Similar terms are also used in Buddhist Vipassana meditation. Samana is related to Sushumna nadi and is linked to Kundalini  Activation. 

We do not always breathe through both the nostrils, usually one nostril is open and the other is partially or fully closed (Alternate Rhinitis). In Yoga, this is known as Swara. Breath alternates between Ida & Pinagala every hour which in turn is associated with activation of right & left hemispheres respectively. When the left Nostril is flowing, it means the Ida is active & the mind is dominant, When the right nostril is flowing it means the breath in Pingala is active and the pranas are predominating.

If the Ida is flowing and you are practicing meditation, you will go to sleep and your brain will produce delta waves. If the right nostril is flowing and you are trying to meditate, your brain will produce beta waves and your mind will be full of thoughts. 

When both nostrils are flowing equally that means Sushumna is flowing. Sushumna is conducive to meditation. Thus Sushumna activation is a prerequisite for Kundalini activation.

During flow of Ida one should do quiet tasks associated with mental creativity while during flow of Pingala, physical work should be done which require logic and systematic thinking. Sushumna flow is conducive to Yoga & dhyana.

Different Manifestaions of the three Nadis are tabulated as under:

Ida (Breath through Left Nostril is freely flowing)	Sushumna (Balanced & equal flow)	Pingala (Breath through Right nostril is flowing freely)
Feminine	Androgynous	Masculine
Night	Sunrise/Sunset	Day
Moon	Cosmic Light	Sun
Cold	temperate	Hot
Internal/Passive	Centred	External/Active
Ganga	Saraswati	Yamuna
Blue	Yellow	Red
Brahma	Rudra	Vishnu
Sattwa (Tamas after awakening)	Tamas (Sattwa after awakening)	Rajas
Chitta Shakti	Kundalini Shakti	Prana shakti
Intuition	Wisdom	Logic
Sub conscious Mind	Unconscious Mind	Conscious Mind
Parasympathetic nervous System	Sympathetic nervous System	Central nervous system
Prana vayu (In Breath)	Samana prana	Apana (Out Breath)