Shabda or Sound is omnipresent in this Universe. In fact the very character of Akasha or Sky or Space (Vyoma) is Shabda or sound. This entire creation has emerged from sound. Even the path beyond the dimensions of creation goes through sound. An individual can attain Param Bramha by first conquering or piercing Shabda Bramha.
The 1st step on the path to Nada-Bramha is through chanting of AUM. AUM is 3 &1/2 Dimensional.
A – Bramha, U – Vishnu , M – Maheshwar (3 Dimensions ). The remaining 1/2 dimension is Chandra Bindu (cresent moon with the dot). The 3 dimensions represent Bhur (Earth), Bhuva (Sky) & Swah (Heavens). They also represent Existence, Consciousness and Bliss.
The 1/2 dimension is the path from the Conscious to the Superconscious level. From Shabda Bramha to Param Bramha.
Every Mantra in the Sanatana Dharma (Hinduism) begins with AUM. Because AUM is like a boat. Riding on this boat leads to Param Bramha.
AUM is Life. AUM is Sound. AUM is Light.