Have you ever wondered how vision and hearing works? This course covers the basics, from a computational perspective. The course consists of three parts. The first part reviews the environment in which vision and audition occurs. For vision, we discuss color, shading, binocular disparity, optical flow, and focus. For audio, we discuss how the head reshapes the sound that arrives at the ear. We then discuss how visual images and audio signals are processed by the brain. Finally we examine the problem of visual and auditory perception, namely how properties of the environment such as geometry, position of objects, and materials of objects are inferred.