If the breath did not manifest through the voice, it would manifest in some other way, as the absent sound of thought. Wherever it is directed, it will go. If you do not speak and yet think the same thought, the breath will travel silently. People think they cannot hear except with their ears, they are so attached to their physical body. But as soon as a man is convinced that he can hear without ears, he will do so without speech. One can tell that a person is angry without his speaking, because he reveals it in his whole vibration. The very way a person says "yes" tells you whether he is willing or not willing; it depends on the character of the breath at that moment.