A major role for hearing is to determine the sources of sounds. Since the sounds from many sources are combined into one complex sound field as the input to the auditory system, the auditory system must determine what aspects of this sound field are unique to each sound source. Analytic listening indicates that a listener is able to segregate the information in a sound field according to sources, while synthetic listening represents a failure to segregate. A new procedure, the Synthetic / Analytic Listening Task (SALT), is used to measure analytic and synthetic listening in two tasks: a lateralization task in which interaural time differences are the basis for sound source segregation, and a modulation discrimination task in which amplitude modulation is the basis for sound source segregation. The SALT procedure is more useful in describing performance related to sound source determination than are the more traditional procedures based on measures of threshold.