Principles of Auditory Object Formation by Nonhuman Animals

Abstract

Early in the twentieth century, the Gestalt psychologists outlined principles governing the ability of the human visual system to construct integrated percepts of objects in visual scenes. By the close of the twentieth century, ample evidence suggested that the human auditory system follows similar principles of perceptual organization. Several Gestalt principles of grouping—proximity, similarity, common fate, good continuation, and familiarity, govern our ability to decompose complex mixtures of sounds into percepts of auditory objects in acoustic scenes. Auditory objects are perceptual groupings of sounds generated by the same source that are present at different times and in different parts of the frequency spectrum. The ability to form auditory objects likely plays an important role in allowing animals to navigate human-altered soundscapes. This chapter reviews studies of insects, fish, frogs, birds, and nonhuman mammals in which experimenters manipulated potential grouping cues and measured performance on behavioral tasks designed to reveal the animal’s perception of auditory objects. These studies employed techniques ranging from measuring natural behaviors in response to communication signals to operant conditioning of responses to artificial sounds such as pure tones. The totality of the studies reviewed here unequivocally reveals that nonhuman animals not only form auditory objects but that they also follow the Gestalt principles of grouping. These principles and their underlying mechanisms allow animals to perceptually organize the often noisy and complex acoustic environments in which they live.