Madhudvisa: Prabhupada, I have heard from different sources that there is a vibration that is going on in the universe at all times. When they refer to this vibration, are they referring to the om, the sacred om vibration? 

Prabhupada: First of all, you should stop to receive any knowledge from any other source.

Madhudvisa: Well, I'm not taking it as knowledge, I'm just…

Prabhupada: No, you said that "I have heard from different sources."

Madhudvisa: From people on the street that I've talked to.

Prabhupada: Yes. So what is the question?

Madhudvisa: They talk about the vibration that's going on in the universe at, uh, at all times, and they talk about vibrating with this vibration, and uttering this vibration, and that this is what they're after.

Prabhupada: Yes, any vibration, there is sound. So there is… The sound is heard omkara. That is also accepted in the Bhagavad gita. So there is no objection accepting this…

Madhudvisa: They talk about this as the ultimate stage of…

Prabhupada: Then you have to accept their statement, not the Bhagavad-gita. Therefore I say that you don't hear from all sources. Because they have said that that is the ultimate, would you accept that?… A man in the street, is he greater than Narada? Is he greater than Vyasa? He is greater than Krsna? Then why should I hear him? You should ask him, "Please, keep your theory with you. We are greater authority than you."

>>> Ref. VedaBase => Bhagavad-gita 2.46-62 — Los Angeles, December 16, 1968