“Om” is often chanted at the beginning and/or end of a yoga session. The sound is supposed to be a way to help someone focus during meditation.
A sound or phrase used during meditation to focus the mind is called a mantra, according to Yoga for Dummies.
Mantra Yoga is said to have arisen in the Western world “in the late 1960s during the Transcendental Meditation (TM) movement, founded by Maharishi Mahesh Yogi, whose most famous disciples were The Beatles,” says Yoga for Dummies.
Additionally, the syllable “om” is “composed of the letters a, y, and m, and stands for the waking state, dream state, and deep sleep respectively,” says Yoga for Dummies. “Hindus consider this syllable to be sacred and to symbolize the ultimate reality, or higher Self (atman).”
To effectively perform the “om” sound, yogis need to sit up straight with their legs crossed, in an indian-style pose. A yogi should rest his or her wrists, palms facing up, at the edge of the knees. With closed eyes, hold the lower abs in, take a deep breath and begin to recite the “om” sound.
The vibration of the sound should begin at the navel and eventually work its way up to the crown of the head, according to yogawithsubhash.com.
After repeating this two to three times, yogis should remain still with their eyes closed, continuing to feel the vibrations.