Doubts About the Role of Rehearsal in the Irrelevant Sound Effect

The irrelevant sound effect (ISE) describes the disruption of processes involved in maintaining information in working memory (WM) when irrelevant noise is present in the environment. While some posit that the ISE arises due to split obligation of attention to the irrelevant sound and the to-be-remembered information, others have argued that background noise corrupts the order of information within WM. Support for the latter position comes from research showing that the ISE appears to be most robust in tasks that emphasize ordered maintenance by a serial rehearsal strategy, and diminished when rehearsal is discouraged or precluded by task characteristics. This prior work confounds the demand for seriation with rehearsal. Thus, the present study aims to disentangle ordered maintenance from a rehearsal strategy by using a running memory span task that requires ordered output but obviates the utility of rehearsal. Across four experiments, we find a significant ISE that persists under conditions that should discourage the use of rehearsal and among individuals who self-report use of alternative strategies. These findings indicate that rehearsal is not necessary to produce an ISE in a serial recall task and thus fail to corroborate accounts of the ISE that emphasize the involvement of rehearsal.

Sound Impairment Effect on Cognitive Skill Performance

Autism Spectrum Condition (ASC) is a life-long diagnosis, which has a subset of individualized characteristics consisting of hyper-, seeking- and/or hypo-reactivity to sensory inputs or unusual interests (APA, 2013). These sensitivities are evident in both environmental (e.g. apparent response to specific sounds, visual fascination with lights or movements) and physiological domains (e.g. anxiety, respiration or euthermia). As part of a larger PhD Research Project (SensorAble), this pilot study proposes that autistic individuals who exhibit greater distractibility and reduced focus/attention resulting stimuli may benefit from interventions that alter, redirect and/or attenuate stimuli. In particular, Irrelevant-Sound Effect (ISE) consisting of un-targeted and/or modulated sonics cause greater disruption of performance of simultaneous and visual simple tasks compared to baseline ISE that are merely directed. Using gold-standard Stroop experiments, data collected among neurotypical (NT) and ASC individuals at baseline and at various ISE modes result in greater reaction time (RT) improvements among ASC than NT participants. In this study, which focuses on aural distractibility only, data supports that signal processing may provide a gateway to enhancing focus and attention while reduce distractibility and anxiety in other domains.

The role of talker familiarity in auditory distraction

The current research employed a classic irrelevant sound effect paradigm and investigated the talker-specific content of the irrelevant speech. Specifically, we aimed to determine if the participants’ familiarity with the irrelevant speech’s talker affected the magnitude of the irrelevant sound effect. Experiment 1was an exploration of talker familiarity established in a natural listening environment(i.e. a university classroom)in which we manipulated the participants’ relationships with the talker. In Experiment 2 we manipulated the participants’ familiarity with the talker via 4 days of controlled exposure to the target talker’s audio recordings. For both Experiments1 and 2, a robust effect of irrelevant speech was found; however, regardless of the talker manipulation, talker familiarity did not influence the size of the effect. We interpreted the results within the processing view of the auditory distraction effect and highlighted the notion that talker familiarity may be more vulnerable than once thought.

The Role of Talker Familiarity in Auditory Distraction

The current research employed a classic irrelevant sound effect paradigm and investigated the talker-specific content of the irrelevant speech. Specifically, we aimed to determine if the participants’ familiarity with the irrelevant speech’s talker affected the magnitude of the irrelevant sound effect. Experiment 1 was an exploration of talker familiarity established in a natural listening environment (i.e., a university classroom) in which we manipulated the participants’ relationships with the talker. In Experiment 2, we manipulated the participants’ familiarity with the talker via 4 days of controlled exposure to the target talker’s audio recordings. For both Experiments 1 and 2, a robust effect of irrelevant speech was found; however, regardless of the talker manipulation, talker familiarity did not influence the size of the effect. We interpreted the results within the processing view of the auditory distraction effect and highlighted the notion that talker familiarity may be more vulnerable than once thought.

The role of speech fidelity in the irrelevant sound effect: Insights from noise-vocoded speech backgrounds

The Irrelevant Sound Effect (ISE) is the finding that background sound impairs accuracy for visually presented serial recall tasks. Among various auditory backgrounds, speech typically acts as the strongest distractor. Based on the changing-state hypothesis, speech is a disruptive background because it is more complex than other nonspeech backgrounds. In the current study, we evaluate an alternative explanation by examining whether the speech-likeness of the background (speech fidelity) contributes, beyond signal complexity, to the ISE. We did this by using noise-vocoded speech as a background. In Experiment 1, we varied the complexity of the background by manipulating the number of vocoding channels. Results indicate that the ISE increases with the number of channels, suggesting that more complex signals produce greater ISEs. In Experiment 2, we varied complexity and speech fidelity independently. At each channel level, we selectively reversed a subset of channels to design a low-fidelity signal that was equated in overall complexity. Experiment 2 results indicated that speech-like noise-vocoded speech produces a larger ISE than selectively reversed noise-vocoded speech. Finally, in Experiment 3, we evaluated the locus of the speech-fidelity effect by assessing the distraction produced by these stimuli in a missing-item task. In this task, even though noise-vocoded speech disrupted task performance relative to silence, neither its complexity nor speech fidelity contributed to this effect. Together, these findings indicate a clear role for speech fidelity of the background beyond its changing-state quality and its attention capture potential.

Age differences in the irrelevant sound effect: A serial recognition paradigm

In adults, the disrupting effect of irrelevant background sounds with distinct temporalspectral variations (changing-state sounds) on short-term memory performance was found to be robust. In the present study, a verbal serial recognition task was used to investigate this so-called Irrelevant Sound Effect (ISE) in adults and 8- to 10-year-old children. An essential part of the short-term memory impairment during changing-state speech is due to interference processes (changing-state effect) which can be differentiated from the deviation effect of auditory distraction. In line with recent findings (Hughes et al., 2013), our study demonstrates that the changing-state effect is not modulated by task difficulty. Moreover, our results show that the changing-state effect remains stable for children and adults. This suggests that the differences in the magnitude of the ISE as reported by Elliott (2002) and Klatte et al. (2010) are most likely related to the increase in attentional control during childhood.