Om
the sacred mantra of divinity, the guru of sounds.
Om is divided into 4 sounds and stages. A, U, M, and the sound that is beyond all verbal pronunciation.
A - the beginning of all sounds, a baby's first sound
U - formed moving forward in the mouth
M - hummed, with lips and teeth closed
AUM forms a trinity similar to other trinities: body-mind-spirit, creator-preserver-destroyer, past-present-future...
going further than the trinity, the last bit of breath after the "Om" continues to be released without an audible sound to go with it. this 4th part of "Om" is the unspoken sound, anahatha - the vibration before and after all sound.
if you listen closely after chanting, the resonance of the "mmm" sound can be felt.
all other Sanskrit mantras come from the root vibration "Om". as "Om" is so subtle, other mantric vibrations are added to allow the mantra to be more easily experienced - a good example: "Om Shanti".
by constant repetition of any mantra, the cells in our body and mind vibrate with the chosen sound and it's qualities.
in the Yoga Sutras it says:
repeating the sacred sound manifests Divine Consciousness
sit comfortable and choose a mantra or a prayer that fills your heart with love. it doesn't matter if you do know the exact meaning, the feeling is most important.
then begin to repeat the mantra/prayer aloud in a soft voice. let the vibration, step by step, fully take over until you only whisper, making it even further - let the heart repeat in silence. you'll still feel the vibration. try to feel the vibration moving in and out of your heart, nourishing yourself completely.
with that, even after you finished your quiet time of mantra repetition, the mantra will be with you and be repeated with each beat of your heart throughout the day.
why not give it a try?
truth is one, many are the paths (Vedas)