Switching attention between the ears to monitor tones Nigel Harvey

Alternating dichotic presentation of tones was compared with monaural presentation in two different perceptual tasks. When Ss were asked to detect higher frequency target tones in fists of six background tones, they missed less than 5%. However, when the presentation was fast (10/sec) and the tones alternated dichotically, Ss reported “hearing” only three or four tones. In two further experiments, Ss were asked to judge the number of tones or to report their spatial and temporal positions; these tasks were much less accurately performed, for the dichotic lists, than the target detection task. The differing effects of switching rate on these tasks are discussed in relation to the types of processing they require.