Perceiving the initial note: quantitative models of how listeners parse cyclical auditory patterns

Perceptual grouping in complex rhythmic patterns

Perception of simple temporal patterns has been shown to rely on accentuations in terms of intensity, pitch, or timbre, but also on grouping according to runs of the same events (intervals between successive sounds or light flashes) or significant gaps between them (Garner in The processing of information and structure. Lawrence Erlbaum, 1974; Preusser et al. in Am J Psychol 83(2):151-170 in 1970; Royer and Garner in Percept Psychophys 1(1):41-47, 1966; Royer and Garner in Percept Psychophys 7(2):115-120, 1970; Yu et al. in Atten Percept Psychophys 77(8):2728-2739, 2015). Here we investigate whether the run and gap principles can also account for participants' perceived start of complex rhythmic patterns. We also investigated the role of participants' musical training. Sixteen novices and 16 amateur musicians listened to rhythmic patterns and indicated perceived starting points by a single tap with a drumstick on electronic pads. Auditory patterns contained prominent gaps, runs, or a combination of the two for target intervals. We systematically varied task complexity in terms of the target durations of intervals constituting the patterns and overall tempos. Overall, run and gap principles proved to be useful grouping principles accounting for a large proportion (59.2%) of the selected starting positions underlining the universal relevance of these principles. Grouping principles were not as successful in predicting the perceived start of a rhythmic pattern compared to previous studies. Results indicate that additional grouping principles must be at play. Predictive power of the grouping principles varied depending on the structure of rhythmic patterns. For rhythmic patterns including longer intervals (i.e., longer gaps) the gap principle alone or in combination with the run principle showed the strongest predictive power. Novices and amateur musicians were similar in their usage of grouping principles suggesting that the underlying principles might be equally at the dispositions of performers and listeners.

Task-set control, chunking, and hierarchical timing in rhythm production

We investigated task-set control processes and chunking in 16 novices and 16 amateur musicians, who produced unimanual rhythms in three experimental conditions: low-level timing tasks required isochronous tapping at constant target durations; sequencing tasks consisted of individual rhythmic patterns comprising multiple target durations; the task-set control condition required alternations between two rhythmic patterns. According to our hierarchical timing control model conditions differed in their task-set control demands necessary to provide rhythm programs for the sequencing of individual intervals. Transitions at predicted chunk boundaries were marked by increased frequencies of sequence errors, relative lengthening of intervals preceding the switch to a new rhythm chunk, and increased variabilities in intervals immediately following a switch. Amateur musicians showed superior timing (less variability) in complex rhythm tasks. Moreover, they made fewer sequence errors than novices at set-switch points with their error patterns suggesting that they relied on larger chunks compared with novices. Our findings elucidate the time course of task reconfiguration processes in rhythm production and the role of chunking in the context of musical skill.

Competition between Rhythmic and Linguistic Meaning Revisited: The Effect of Task Demands

This paper revisits the conclusion of our previous work regarding the dominance of meaning in the competition between rhythmic parsing and linguistic parsing. We played five-note rhythm patterns in which each sound is a spoken word of a five-word sentence. We asked listeners to indicate the starting point of the rhythm while disregarding which word would normally be heard as the first word of the sentence. In four studies, we varied task demands by introducing differences in rhythm complexity, rhythm ambiguity, rhythm pairing, and semantic coherence. We found that task complexity affects the dominance of meaning. We therefore amend our previous conclusion: when processing resources are taxed, listeners do not always primarily attend to meaning; instead, they primarily attend to the aspect of the pattern (rhythm or meaning) that is more salient.