They are strange experiences—a voice whispered on the wind, a god who speaks from on high—but far more common than we think. At the beginning of most great religions lies a voice. Who hears such voices?  I have spoken to hundreds of people, in many countries, who have heard voices, some only once, some more often. Most of these people are not psychiatrically ill. Some are. In this talk I will discuss what we know about the difference between mad voices and sane voices, and what traits and practices and cultural ideas make sane voices more likely. I will also argue that these experience teach us something fundamental about the nature of human awareness.