The PERCEIVING category includes articles associated with perceptual experiences, especially those experiences that involve perceptions of three-dimensional scenes. Several articles include perceptions of depth and distance, size and shape. Others include the perception of object motion (both direction and velocity) and self-motion. Perceiving also includes aspects of auditory perception – the locations from which sounds seem to originate, the errors we may make about such locations, the apparent loudness of sounds, and so forth. As in other portions of the website, some articles may be categorized under multiple headings, e.g., articles about a particular visual experience might also be included under Seeing, or an article about how we perceive the apparent distances of sounds might also be categorized under Hearing.