Effect of timing variations on the categorical perception of musical rhythm patterns
Georgios Papadelis, George V. Papanikolaou · The Journal of the Acoustical Society of America · 1999
Musical rhythm patterns are mainly characterized by durational relationships between their different time levels. As written rhythmic values imply, these relationships are graphically represented by simple integer ratios and that fact reflects a basic criterion for their perceptual encoding into discrete perceptual categories. Temporal analysis of any musical performance reveals that deviations from accurate metronomic timing is a very common practice among musicians and these deviations are perceived either as musical expressivity, or just as inaccurate performance of rhythm. The degree of deviation also affects the categorization of a certain rhythmic pattern. In the present study, a mapping of the perceptual space between adjacent rhythm categories was attempted, through a systematic timing variation of simple rhythm patterns, as well as the investigation of the perceptual magnet effect [P. Iverson and P. Kuhl, J. Acoust. Soc. Am. 97, 553–562 (1995)] at various musical tempi. Sixteen musicians participated in identification, goodness rating, and discrimination tasks. The relative strength of the prototype within each category was determined, as well as the change in the position of category boundaries in different tempi. Discrimination graphs were finally plotted and comparisons were performed between the positions of discriminability peaks and the related category boundaries.