Sensitivity to statistical structure facilitates perceptual analysis of complex auditory scenes

Abstract

The notion that sensitivity to the statistical structure of the environment is pivotal to perception has recently garnered considerable attention. Here we investigated this issue in the context of hearing. Building on previous work (Sohoglu & Chait, 2016b), stimuli were artificial 'sound-scapes' populated by multiple (up to 14) simultaneous sources ('auditory objects') comprised of tone-pip sequences, each with a distinct frequency and pattern of amplitude modulation. Sequences were either temporally regular or random.We show that listeners' ability to detect abrupt appearance or disappearance of a source is facilitated when scene sources were characterized by a temporally regular fluctuation pattern. The patterning of the changing source as well as that of the background (non-changing) sources contribute independently to this effect. Remarkably, listeners benefit from regularity even when they are not consciously aware of it. These findings establish that perception of complex acoustic scenes relies on the availability of detailed representations of the regularities automatically extracted from each scene source.

Linguistic predictability influences auditory stimulus classification within two concurrent speech streams

“…This result ties in well with those of Southwell and Chait (), who also found larger deviance related responses to deviants appearing in task‐irrelevant regular than random sequences. However, overall, ignored regular sequences capture less attention than random ones (Aman et al, ; Southwell et al, ) and we did not find signficant effects of linguistic predictability either on the distractor P3a (reflecting attention capture) or on target detection (P3b or behavioral). Therefore, the distractor N2 effect cannot be taken as a sign that distractors would have captured more attention with higher than lower linguistic predictability.…”

“…This assumption has been experimentally supported by a number of studies comparing target detection between predictable and random sound sequences (see, e.g., Chait et al, ). Further, while regular sound patterns elicit higher‐amplitude EEG activity than random ones (Sohoglu & Chait, , Southwell et al, , including responses to deviance: Southwell & Chait, ), in the presence of a concurrent sequence, regular sequences induce less attentional capture than random sequences (Aman, Picken, Andreou, & Chait, ; Southwell et al, ). These results are compatible with findings that regularities in one or both of two concurrent sound sequences contribute to stream segregation and selection (e.g., Andreou et al, ) not only by facilitating focusing on the selected stream, but also by promoting the suppression of the to‐be‐ignored stream (Aman et al, , see also Szalárdy, Winkler, Schröger, Widmann, & Bendixen, ).…”

Predictive coding in auditory perception: challenges and unresolved questions

“…Listeners were faster and more accurate in detecting the emergence of an additional tone sequence within the regular than in the random context, suggesting that the regular context allowed them to quickly identify tones that did not conform to any of the previously encountered sequences. These results were then extended in a separate series of experiments (Aman et al ., in press) to different numbers of parallel sequences, appearance and termination of a target sequence, and non‐isochronous regularities. Further, the results suggest that listeners do not need to be aware of the presence of the regularities for utilising their advantages in detecting changes in the sequences.…”

“…Overall, the picture emerging about the role of predictable patterns in sound processing is that (1) the human auditory system is sensitive to patterns and statistical regularities in sequences of sounds, (2) detecting regularities does not require attention to be focused on the sounds (Sussman, ) and listeners are not necessarily aware of the detected regularities, for example (van Zuijen et al ., ; Paavilainen et al ., ; Aman et al ., in press) and (3) the utilisation of regularities varies with context and experimental details in ways that have yet to be fully understood. Taken together, what these studies show is that the influence of predictability on perceptual organisation is not mandatory.…”

The effect of healthy aging on change detection and sensitivity to predictable sturcture in crowded acoustic scenes

“…Changes, manifested as the abrupt disappearance of one of the sources, were introduced to a subset of the trials and participants were instructed to monitor the scenes for these events. Similar stimuli were previously used for the study of change detection ability in young listeners (Aman et al, 2018;Cervantes Constantino et al, 2012;Chait, 2016a, 2016b).…”