 But is the claim that there are no sounds in vacuums really obvious? On pain of question begging, it cannot be made to follow from any particular metaphysics of sounds. In order to assess it on its own merits, consider once more the analogy between, on the one hand, sounds and air, and, on the other hand, emission events at light sources and light. Air is the medium of auditory perception, and light is the medium of visual perception. The reasoning now is that just as things can sensibly be taken to have colors in the dark, they can sensibly be taken to produce sounds in a vacuum.