Coherence of the irrelevant-sound effect: individual profiles of short-term memory and susceptibility to task-irrelevant materials.

We examined individual and developmental differences in the disruptive effects of irrelevant sounds on serial recall of printed lists. In Experiment 1, we examined adults (N = 205) receiving eight-item lists to be recalled. Although their susceptibility to disruption of recall by irrelevant sounds was only slightly related to memory span, regression analyses documented highly reliable individual differences in this susceptibility across speech and tone distractors, even with variance from span level removed. In Experiment 2, we examined adults (n = 64) and 8-year-old children (n = 63) receiving lists of a length equal to a predetermined span and one item shorter (span-1). We again found significant relationships between measures of span and susceptibility to irrelevant sounds, although in only two of the measures. We conclude that some of the cognitive processes helpful in performing a span task may not be beneficial in the presence of irrelevant sounds.