High working memory capacity attenuates the deviation effect but not the changing-state effect: further support for the duplex-mechanism account of auditory distraction.

Serial short-term memory is impaired by background sound, at least when a sound element suddenly deviates from an otherwise repetitive sequence (the deviation effect) and when each sound element in the sequence differs from the preceding one (the changing-state effect). Two competing theories have been proposed to explain these effects: One suggests that both effects are caused by the same mechanism (i.e., attentional resources being depleted by the sound), and the other suggests that the deviation effect is caused by attentional capture and that the changing-state effect is caused by interference between order processes. The present investigation found that working memory capacity predicts susceptibility to the deviation effect, but not to the changing-state effect, both when speech items (Experiment 1) and when tones (Experiment 2) produce the disruption. These results suggest that the two effects are caused by different mechanisms and support the duplex-mechanism account of auditory distraction.