'This Sphota has one word as its only possible symbol, and this is OM. And as by no possible means of analysis can we separate the word from the idea, this OM and the eternal Sphota are inseparable; and therefore it is out of this holiest of all holy words, the mother of all names and forms, the eternal OM, that the whole universe may be supposed to have been created. But it may be said that, although thought and word are inseparable, yet as there may be various word-symbols for the same thought, it is not necessary that this particular word OM should be the word representative of the thought out of which the universe has become manifested. To this objection we reply, that this Om is the only possible symbol, which covers the whole ground, and there is none other like it.The Sphota is the material of all words, yet it is not any definite word in its fully formed state. That is to say, if all the particularities, which distinguish one word from another be removed, then what remains will be the Sphota; therefore this Sphota is called Nada-Brahman, the Sound-Brahman. Now , as every word- symbol intended to express the inexpressible Sphota will so particularize it that it will no longer be the Sphota, that symbol which particularizes it the least and at the same time most approximately expresses its nature, will be the truest symbol thereof; and this is the OM, and the OM only; because these three letters A, U, M, pronounced in combination as OM, may well be the generalized symbol of all possible sounds. The letter A is the least differentiated of all Sounds. Again, all articulate sounds are produced in the space within the mouth beginning with the root of the tongue and ending in the lips- the throat sound is A, and M, is the last lip sound; and the U exactly represents the rolling forward of the impulse which begins at the root of the tongue , continuing till it ends in the lips, If properly pronounced this OM will represent the whole phenomenon of sound production, and no other word can do this; and this, therefore, is the fittest symbol of the Sphota, which is the real meaning of OM. And as the symbol can never be separated from the thing signified, the OM and the Sphota are one. And as the Sphota, being the inner side of the manifested universe, is nearer to God, and is indeed the first manifestation of Divine Wisdom, this OM is truly symbolic of God.' - Swami Vivekanda, the lion.