Perceived Location

Up to now, little attention is paid to the location where a sound is perceived as coming from. This is done because that part of the perceptual system that estimates the location of a sound source, and that which determines what is heard, work to a large extent independently of each other up to high levels of the auditory system. This chapter discusses what auditory information is used in human sound localization. It is shown that more than a dozen sources of information are used varying from the time and intensity differences with which a sound reaches both ears, to the Doppler effect and moving around. It turns out than none of these sources of information on its own is enough to accurately localize a sound in less than two dimensions. This implies that accurate localization can only be realized for sounds rich in information and by combining the information from various of these sources of information. A description is presented of how various sources of information are used to estimate the distance of the sound source from the listener and the direction where the sound comes from, i.e., the azimuth and the elevation. The role played by moving around is underscored. This chapter ends by showing that auditory localization is a very plastic system continuously adapting to changing situations.