Whether the Voice is Incorporeal. what is it that the Gives Echo?

Pythagoras, Plato, and Aristotle declare that the voice is incorporeal; for it is not the air that causes the voice, but the figure which compasseth the air and its superficies having received a stroke, give the voice. But every superficies of itself is incorporeal. It is true that it move with the body but itself it hath no body; as we observe in a staff that is bended, the matter only admits of an inflection, while the superficies doth not. According to the Stoics a voice is corporeal since everything that is an............