Irrelevant Speech, Serial Rehearsal, and Temporal Distinctiveness: A New Approach to the Irrelevant Speech Effect

D. C. LeCompte (1994) showed that the irrelevant speech effect-that is, the impairment of performance by the presentation of irrelevant background speech-extends to free recall, recognition, and cued recall. The present experiments extended the irrelevant speech effect to the missing-item task (Experiments 1 and 2), thereby contradicting a key prediction of the changing state hypothesis, which states that tasks that do not involve serial rehearsal should not be affected by the presence of irrelevant speech. Temporal distinctiveness theory provides an alternative explanation of the irrelevant speech effect. Experiment 3 tested and confirmed a unique prediction of this theory.