OM or AUM
Aaahh: represents the beginning of sound and the aspect of the creation of the universe. (remember universe is a compound word of two words Uni, meaning one and Verse meaning spoken word of phrase) this sound stimulates and resonates with the Throat Chakra which controls your spiritual drive.
OOO: this sound signifies the maintaining energy of the universe and connects the self to a higher state of being. The sound stimulates the Naval Chakra which is the seat of power and drive.
MMMMM: Represents the trans-formative energy of the universe and the thoughts and beliefs of your being or self. The sound allows you to slow down and feel the connection with all that is in existence. The Mmmm sound when prolonged has a looping effect first it stimulates the root chakra which controls fear and helps root oneself to the here and now, then moves itself back up to the crown chakra which is your spiritual centre and your connection to the divine.
Silence: the space between each chant that represents a vibration beyond that of verbal pronunciation. It is pure consciousness of the self (I exist, I know, I am blissful)