It should be kept in mind that man discovered these words and did not invent them.
Whether we classify this discovery as a result of Divine revelation or from experiments on the part of the sincere seeker, the fact remains that man did not arbitrarily select the sounds of "ah" and "m" but found that of all the sounds he could utter these were associated definitely and positively with Divine and creative power that produced certain effects within his being and within his aura around him.
The mere fact that in many different countries widely separated and out of contact with one another, the natives in ancient times independently adopted the similar sounds in their rituals and chanting, for the same purpose, most certainly proves that there is a power and a quality in these particular vowels and in their uttered sound that cannot be found in other words.