Constant "segmental anchoring" of F0 movements under changes in speech rate.

This study develops the notion of the "segmental anchoring" of F0 movements, specifically, the finding that both the beginning and the end of a rising pitch accent are anchored to specific points in segmental structure [Arvaniti et al., J. Phonetics 26, 3-25 (1998)]. If there are segmental anchors for rising accents (and if, as shown by Arvaniti et al., the F0 level of the beginning and ending points is unaffected by the experimental manipulations), the anchors should be closer together as the speaking rate increases, and the rises should therefore be shorter and steeper. This was tested in two experiments in which speakers were asked to modify rate. The first experiment confirmed the basic prediction that the duration of accentual F0 rises is affected by changes in rate. The second experiment studied the alignment of the beginning and ending points with their hypothesized segmental anchors. For all speakers there was a strong correlation between the duration of the rise and the time interval between the anchors, but only small and inconsistent effects of rate on alignment. Effects of rate on F0 excursion size were likewise small and inconsistent. The results support a model in which pitch accents consist of "tonal targets," and in which the alignment and F0 level of tonal targets are what determine a pitch accent's shape.