The first time Corey received his Ears of Omniscience, he thought the only thing it could do was to improve his hearing by an extremely high degree, however, after practicing and experimenting quite a bit with it, he realized that his Ears of Omniscience were not simple at all.
In the Mystic Realm, there was something called The Language of Mysticism.
The difference between the Mystic Realm and the Astral Realm was extremely vast, and there were countless reasons why Mystic beings treated Astral beings with indifference, arrogance, and disdain.
When one reached the Mystic Realm they could start learning the Language of Mysticism, and depending on their foundation, talent, and mental fortitude, the easier or harder it would be to learn the Language of Mysticism.
Mystic beings could speak the language of mysticism, and only other Mystic beings or beings higher than the Mystic realm would be able to understand the words spoken in the language of mysticism.