The Upanishads

, the third sound.
This initiates measurement and merging.
Whoever awakens to this merges with the world yet has the measure of all things

This initiates upholding and unification.
Whoever awakens to this upholds the tradition of knowledge and unifies the diversities of life.
Everything that arises speaks to him of brahman.

Experience of the inner world corresponds to U, the second sound.

Experience of the outer world corresponds to A, the first sound.

It is known only through becoming It.

This state beyond duality—from which the waves of thinking emerge—is enjoyed by the enlightened as an ocean of silence and bliss.

The third is deep sleep.

The second is experience of subjective worlds, such as in dreaming.
Here the attention dwells within, charmed by the mind’s subtler creations.

waking state.
This is the experience of the reality common to everyone, when the attention faces outwards, enjoying the world in all its variety.

An object is experienced only when it colors the mind. But the mind itself is always experienced because it is witnessed by the unchanging Self. The mind does not shine by its own light. It too is an object, illumined by the Self