Noise effects on rate of rehearsal in short term memory

Abstract

Chapter 1 reviews the literature on the effects of noise within three memory paradigms. This review shows a general trend indicating that noise increases reliance on order information.

Chapter 2 thus attempts to establish a relationship between the recall of order information and the use of phonological coding and suggests that noise, in some way, interferes with the efficiency with which phonological codes are used.

Chapters 3--6 then describe ten experiments carried out to test this hypothesis. Experiments 1--4 showed that noise improved serial order recall of acoustically similar letters and that noise effects were more likely to be observed in conditions where rehearsal depended on some internally stored representation rather than being guided by visually available items.

Experiments 5 and 6 investigated the effects of noise on recognition and a free recall task and generally found no effects.

Experiments 7 and 8 showed that overt rehearsal of items in noise was slower. Experiment 9 then showed that slowing of rehearsal had different consequences on memory performance depending on the spoken length of the to-be-remembered items. A model was described to explain the improvement in recall of acoustically similar items presented in noise, as well as the impairment in recall of dissimilar items and of words of long spoken length.

Experiment 10 showed that retrieval of phonological codes was impaired by noise while no effects were observed on the retrieval of semantic codes. This was suggested as being responsible for the preference which subjects show for adopting maintenance rehearsal strategies, which may in turn produce the effects observed in noise of improvement in order recall but impairment in semantic processing.

The final chapter integrates the above evidence in an attempt to explain the strategic nature of noise effects on memory performance.