Perceptual organization and precategorical acoustic storage.

Current views of precategorical acoustic storage (PAS) have been largely based on differences in the level of recall of terminal list items as a function of input modality and on experiments in which various types of suffixes are added to unstructured auditory lists. Experiments with grouped lists reveal that PAS can make a far more extensive contribution to serial recall. A series of four experiments investigated grouping effects in relation to existing accounts of consolidation, attentional selection, and auditory masking in PAS. Grouping effects obtained with very brief intralist pauses were inconsistent with the consolidation and masking hypotheses. Contrary to the attentional hypothesis, nontemporal grouping by voice or by spatial location was found to be as effective as grouping by extended pauses. When nontemporal methods of grouping were combined with intralist pauses, the two sets of grouping cues were no better than one, suggesting that list segmentation by pauses and by item attributes must be explained in terms of a single process. These results are discussed in the context of previous research that implies the existence of an auditory store with a capacity greater than previously attributed to PAS. Existing data on modality and suffix effects are seen as specific instances of a more general relation between the structure of spoken sequences and their subsequent recall.