"Ong is the sound that man found out of the conch where he put in the breath of life. The sound of the conch is an expanded Ong. When a disciple or seeker practices at the center of the nose, his entire brain gets a very specific vibration and then the nectar starts coming.
"Through time man started writing and reading about the chanting of Ong, but not practicing it. The result was that he eventually forgot what the sound is and then he became a shopper. He went from one place to another, to another, to another. He went from one person to another person to another person, asking, begging for happiness. He went from one religion to another, from one house to another, just asking for peace. He forgot that what he is asking for is within himself." -Yogi Bhajan
Posture: Sit in Easy Pose with the spine straight, chin in and chest out. Jalandhar Bandh (Neck Lock) is especially important for this meditation.
Mantra and Breath: Begin chanting Ong in the long form so that it takes approximately 10 seconds to chant one time. Chant though the “conch,” focusing at the Third Eye Point, making the sound nasal. The mouth is slightly open and the breath comes only out of the nostrils. Chant in this manner 5 times.
Then gradually begin to chant Ong faster so that you are chanting one Ong every 3-5 seconds. The mouth is slightly open, and the sound is created by opening and closing the back of the throat, focusing and vibrating at the Brow Point. Start with 1 minute of rapid Ong and gradually work up to 2 minutes.
"Practice it. It will set your brain if you do it correctly. If you start to cough, allow it, because it is just your thyroid adjusting to the pressure. The thyroid is responsible for beauty and for keeping you young. Chanting this sound correctly gives power, beauty, and youth.
There is no word 'Om'; neither 'Aum.' Actually the sound 'Om' is the sound of the conch, which can only be created. It cannot be written and it cannot be expressed. It is the sound of Infinity (in Formlessness). When this starts working, even the loincloth is lost. It frees the man of all possessions.
Ong is never chanted though the mouth, it comes through the central nerve channel, the Sushmana, which is the tip of the nose. It brings out from you the breath like fire." - Yogi Bhajan
© The Teachings of Yogi Bhajan
This meditation can be found in the manual Praana, Praanee, Praanayam.