Auditory spatial perception provides a unique evolutionary advantage over other senses. In the majority of species, at any moment, vision is only able to sample a limited extent of the surrounding environment. By contrast, auditory spatial perception is periphonic; that is, it can simultaneously sample every direction around the animal and is extremely sensitive to soft, transient sounds (be they prey or predator), at a distance, with obvious evolutionary advantages. Many sounds of interest occur on a background of other sounds, and segregating and locating the different sources have a high ecological value.

Sound sources share a range of perceptual characteristics. They have a location in space relative to the listener, characterized by direction and distance from the head. They have a size or spatial extent ...