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An experiment examined how the orienting of auditory attention is maintained over time (from 1,5 seconds to 3 seconds) as a function of cue type (the words « right » or « left » presented binaurally, or a lateralized tone cue). The hypothesis is that, for the longest delay between cue and target, orienting attention to one ear determined by the cue words «left» and «right» presented binaurally leads to a better detection of verbal targets presented dichotically with distractors as compared to orienting determined by a peripheral sound presented only in the to-be-attended ear. Two rates of presentation of the dichotic stimuli pairs were used, resulting in cue/target delays of 1,5 seconds (fast rate) and 3 seconds (slow rate). Two dummy pairs which never contained any target were also inserted between the cue and the target.
The main result is an interaction between cue type and the rate of presentation. The mean latency of a correct verbal response was slowest in the left attended ear at a slow rate and when the cue was a lateralized tone. This result suggests that attentional focusing is more easily dissipated when orientation is provoked by a lateralized tone cue. This interpretation is discussed in the context of Posner's (1980) and Mondor and Bryden's (1992a, b and c) proposed distinction between deliberate endogenous orienting and automatized exogenous orienting. This distinction stresses the fact that deliberate orienting of auditory attention leads to a more robust focusing (longer lasting and more resistant to distraction) than automatic exogenous orienting.
