Subjects were asked to match the lateral position of one tone, the “signal,” by means of another, the “pointer.” The two tones were presented alternately. The experimenter selected a combination of interaural time and intensity differences for the signal, and the subject adjusted the interaural time difference for the pointer until it seemed to him to be in the same lateral position as the signal. Subjects having normal hearing perceived the signal in two places, one strongly affected by the difference of level at the two ears, the other almost wholly dependent upon the difference of time.