What is Om?

"I am the syllable Om." (Bhagavad Gita 7:8)
Om is the sound of existence. When one focuses his attention on the sensation of existing or "being" without an accompying cognitive aknowledgement (or thought about it or anytthing else) through meditation, yoga, pure love, prayer; one still recieves input, experiences sensation and the only way to describe the input of plain existence is by the sound "om" becuase the reception has a subtle vibration (remember sound is a vibration) which can be interpreted as the sound "AHHHHHH-MMMMMMMMMM". This input of "pure existence" is likewise called God, Allah, Brahman, Christ Consciousness in other spiritual traditions which may emphasize awareness of plain existence. Like water and the sun same thing, many different names dependent on culture.