 What hinges on the debate about hearing sources? The first upshot is epistemological and concerns the nature of the justification for empirical beliefs grounded in perceptual experience. The evidential status of beliefs about what one perceptually experiences differs from that of beliefs about what is causally responsible for what one perceptually experiences. So, whether or not we hear sound sources impacts the epistemology of audition. The second upshot concerns the relation between audition and certain actions. If we hear only sounds and auditory objects, what appears to be effortless, auditorily guided action to avoid or orient toward sound sources requires another explanation (because sounds are invisible and usually do no harm). Finally, it affects how we understand the adaptive significance of audition. Did audition evolve so as to furnish awareness of sounds alone, while leaving their environmental significance to extra-perceptual cognition, or did it evolve so as to furnish perceptual responsiveness to the sources of sounds?