Chapter II. Thought On Pranayama
1. Gyan Mudra or the Mudra of Knowledge 2. Vayu Mudra or Mudra of Air 3. Shoonya Mudra or The Mudra of Emptiness 4. Prithvi Mudra or the Mudra of Earth 5. Prana Mudra or the Mudra of Life
Nada yoga is divine union through sound . Described in the "Hatha Yoga Pradipika" as one of the most powerful and fruitful meditation techniques to calm the mind.