According to Osho, the authentic nada (inner sound) should arise spontaneously, not be produced by chanting Om. When sounds come of their own accord they are precious and true; when evoked through technique they may be mere imagination or autosuggestion. Let meditation create silence and receptivity; then nada reveals itself without effort or willful manufacture.
Real inner sounds should show up by themselves; if you force them with Om, you might just be imagining them.
From the Discourses
Passages where Osho speaks to this question — each links to the complete discourse.
You said that through the practice of Om, nada arise. Do the nada also arise automatically?
If they arise automatically, they are more precious; if they arise of their own accord, they are more precious. If they arise through the use of Om, they may be imagined. They should arise by themselves. Those alone are precious; those alone are true.
You have said that the practice of chanting aum also brings about the nada, the inner sound. Does it come about spontaneously also? Which is the proper nada?
If it comes spontaneously it is more valuable. If it comes with the repetition of aum it can be imaginary. That which comes of its own accord is authentic, valuable. If the nada begins you should become a witness. Do not be merged into it, because that is the state of the seventh plane. If you tend to get lost in the nada before reaching the seventh you will halt there; it will act as a brake. As these inner sounds become more and more subtle, our witnessing too will have to become more and more subtle. We will have to go on observing to the end, when the sound is completely lost.
Om is the fundamental sound of Sanskrit. In Om, all the sounds of Sanskrit are included. Om is made of A, U, and M—the joining of three sounds: A, U, M. These are the three primal vowels; the rest of language is born from them. All words are then constructed of these. Om is the root; A, U, M are its three branches; and from these three branches the whole web of sound and the birth of all words happens. The Jews would call Om the Logos; Christians would call it the Word. This sutra concerns this Om. Understand this sutra well. For those who would enter within can very easily do so with the support of this sound—because it is resonating within. Every moment this sound is echoing inside. This sound is your very life-breath. If this sound disappears within, you disappear.
Thus there are two ways to say it: either call it the soundless Word—the tone that is not born of collision, not born of the impact of two—or the saints have chosen another precious term: Anahata Nada. Anahata means: not produced by striking, not produced by collision. Is there such a sound that is Anahata? Is there a sound born without striking? If there is such a sound, that alone is the fundamental note of life. Several points need to be understood. Whatever is produced by collision will perish. For collision generates a quantity of energy, but how long will that energy last? I clap my hands; the impact of my hands releases a limited force. How long will it resound? Whatever has been produced will be destroyed. Whatever is made will be unmade. Buddha said: that which is compounded cannot be eternal, cannot be Sanatana. How could it be?
Osho, the Upanishads call the ultimate reality invisible, inaudible, and unthinkable. Medieval saints sing of the Word, of nada, and of surati. To give what is inaudible the name of word or audible—doesn’t that increase confusion?
You may read the scriptures, and still it is not understood. You may listen to the saints, and still it is not understood. But this does not mean that there is no nada in the divine. The divine is the supreme nada, the ultimate music, the consummation of rhythm. It has sweetness; it has a wave of sound; it has intoxication. When your ears become empty of all sounds, when you hear nothing outside; when your ears no longer function outwardly; when the entire outer clamor becomes quiet, a void in your life—then even if you are sitting in the marketplace, nothing outer will be heard. When nothing outer is heard, something will be heard within; a wave of sound will arise within, a nada will well up. A flower will blossom in your innermost; it will not enter through the ear. The divine is not outside to enter you—not…