Channels and order of report in dichotic memory*

Experiments were conducted in which Ss received to-be-remembered sequences of two, three, or four simultaneous pairs of digits. Both digits of each pair were recorded by the same male speaker and both were presented binaurally, thus eliminating cues of spatial location and voice by which Ss could “channel” their reports. Even in the absence of these stimulus channels, Ss reported the digits sequentially. High bias ratings in the first experiment suggested the possibility that sequential reports were induced by uncontrolled stimulus characteristics (e.g., temporal synchrony, intensity, and pitch). Pulse-coded speech stimuli, which provided greater control over nonlinguistic stimulus features, were used in the terminal experiment. Bias ratings were reduced, but the majority of Ss continued to report sequentially. These results suggest that the presence of stimulus channels is not a necessary condition for the occurrence of sequential reporting.