“The Ether of the Heart,” the etheric void, free from duality, that exists in the center of the Heart. It is identical to the initial vibration, spanda. According to Abhinavagupta, this eternal Heart is the still and vibrant center of Consciousness, a universal receptacle wherein all the universes are born and withdrawn. He states that from kha surges the non-dual state of bliss where we attain spanda (the Sacred Tremor of the Heart), and to attain spanda is to attain efficiency. Vyoman is a similar term. Khechari Mudra