We use sound to communicate, to identify and locate sound-emitting objects, and to provide us with entertainment through the making of and listening to music. The study of these functions makes up large portions of the psychological study of audition under the categories of speech perception, auditory localization, scene analysis, and music perception. Understanding these topics often requires knowledge of psychological areas that may at first seem to have little relation with them but that are of great importance for understanding them. Some knowledge of the physics of the sound stimulus and of the anatomy and physiology of the ear and brain is needed for the fruitful study of auditory perception. Related fields include acoustics in engineering and the biological and medical study of ...