Extending the irrelevant sound effect beyond serial recall

The finding that serial recall perfonnance for visually presented items is impaired by concurrently presented speech or sounds is referred to as the irrelevant sound effect (lSE). The foremost explanation for the effect is based on interference with rehearsal and seriation processes. The present series of experiments demonstrates tha t neither rehearsal nor seriation processes is necessary to observe the ISE. Evidence comes from three experiments that a) allow participants to report to-be-remembered items in any order, b) eliminate rehearsal by engaging participants in a cover task and surprising them with a memory test, and c) show that surprise non-serial recognition is immune to rehearsal-based experimental manipulations that modulate the ISE in more typical serial recall tasks. Together,the results show that models that rely on rehearsal or seriation processes to account for the ISE need to be reconsidered. Results are discussed in tenns of interference with encoding of to-be-remembered material.