Because all matter is composed of atomic material, which is in constant motion, everything and everyone vibrates on some frequency.
The number of vibrations per second is known as frequency. These vibrations are produced from a source, travel through the air, and then are picked up by the ear before being interpreted by the brain, which assigns them some value. Though many comprehend sound as merely something to be heard, its mechanism is a little more complex. While to the layperson it’s synonymous to meditation, and seen simply as a doorway to tranquility for yogic practitioners, the true meaning of Om is deeply embedded in Hindu philosophy and to comprehend its truly profound effects one must have a basic understanding of sound. Heard in temples, yoga studios, households, even television and movies, the chanting and symbol of Om is familiar to most as it has pervaded the western world since the counterculture of the 1960s.
1) Om is the primordial sound of the universe