Attentional Control and Metacognitive Monitoring of the Effects of Different Types of Task-Irrelevant Sound on Serial Recall

The presence of task-irrelevant sound disrupts short-term memory for serial information. Recent studies found that enhanced perceptual task-encoding load (static visual noise added to target items) reduces the disruptive effect of an auditory deviant but does not affect the task-specific interference by changing-state sound, indicating that the deviation effect may be more susceptible to attentional control. This study aimed to further specify the role of attentional control in shielding against different types of auditory distraction, examining speech and nonspeech distractors presented in laboratory and Web based experiments. To further elucidate the role of controlled processes, we tested whether the detrimental effects of distractor sounds-and their modulation by attentional control-reach participants' awareness. We found that changing-state sound and auditory deviants in steady-state sound equally affected both objective recall performance and metacognitive confidence judgments but did not affect the accuracy of confidence judgments. Most importantly, across four experiments, an increase of task load (visual degradation of the to-be-remembered items) did not reduce either type of auditory distraction. A close replication of the original modulation of the deviation effect by perceptual task load (in an online environment) even revealed a stronger deviation effect at high task load, suggesting that the manipulation may have influenced cognitive load and the ability to control distractor interference in memory. In line with a unitary account of auditory distraction, the results suggest that although both types of distraction reach metacognitive awareness, they may be equally unrelated to perceptual load and the availability of attentional resources. Public Significance Statement Our ability to hold information in short-term memory suffers in the presence of background sound, but it is unclear to what extent auditory distraction depends on attentional control and metacognitive monitoring. This study reassessed a finding, whereby the diversion of attention by deviant sounds is reduced when the focal task becomes more difficult to process (via perceptual degradation). A series of experiments showed that both the effect of auditory deviants and the interference by changing-state sound is largely resistant to a manipulation of task load, indicating that distraction is not susceptible to attentional control. Nevertheless, participants appeared to be well aware of the detrimental sound effects on performance, as reflected in metacognitive confidence judgments. The findings have important implications for theoretical accounts of auditory distraction, indicating that disruption is attributable to automatic attentional capture, which cannot be controlled despite us being aware of it.