Phonological similarity in the irrelevant speech effect: Within- or between-stream similarity?

Irrelevant background speech disrupts serial recall of visually presented lists of verbal material. In 4 experiments, the hypothesis that this disruption is due to the phonological similarity of the irrelevant sound and the list to be recalled was tested. In Experiment 1, item length was controlled and a large irrelevant speech effect was found, but the effect of phonological similarity was small and confined to recency. In Experiment 2, words in the irrelevant stream were used, and the experiment showed an irrelevant speech effect in which phonological similarity played a small part. Experiments 3 and 4 found that similarity (rhyming) within the irrelevant sound stream decreased the level of disruption, and the effect was more marked when the visually presented lists contained items that did not rhyme with one another. Rather than supporting a phonological similarity hypothesis, the results support a changing state hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)