That the sound vibration of the Supreme Lord is identical with the Supreme Lord is a fact. This is confirmed in the Nārada-pañcarātra:
- vyaktaṁ hi bhagavān eva sākṣān-nārāyaṇaḥ svayam
- aṣṭākṣara-svarūpeṇa mukheṣu parivartate
"When the transcendental sound is vibrated by a conditioned soul, the Supreme Lord is present on his tongue." In the Māṇḍūkya Upaniṣad it is said that when oṁkāra is chanted, one attains perfect spiritual vision. In other words, in spiritual vision, or the spiritual world, there is nothing but oṁkāra. Unfortunately, Śaṅkara has abandoned this chief word, oṁkāra, and has whimsically accepted tat tvam asi as the supreme vibration of the Vedas. By accepting such a secondary vibration and leaving aside the principal vibration, he has given up the direct interpretation of the scripture in favor of his own indirect interpretation.
Śrīpāda Śaṅkarācārya has unceremoniously obscured the Kṛṣṇa consciousness described in the puruṣa Vedānta-sūtra by manufacturing an indirect interpretation and abandoning the direct interpretation. Unless we take all the statements of the Vedānta-sūtra as self-evident, there is no point in studying the Vedānta-sūtra. Interpreting the verses of the Vedānta-sūtra according to one's own whim is the greatest disservice to the self-evident Vedas.
As far as the oṁkāra (praṇava) is concerned, it is considered to be the sound incarnation of the Supreme Personality of Godhead. As such, oṁkāra is eternal, unlimited, transcendental, supreme and indestructible. He (oṁkāra) is the beginning, middle and end, and He is beginningless as well. When one understands oṁkāra as such, he becomes immortal. One should thus know oṁkāra as a representation of the Supreme situated in everyone's heart. One who understands oṁkāra and Viṣṇu as being one and the same and all-pervading never laments in the material world, nor does he remain a śūdra.