Fundamental frequency peak delay in Mandarin
Phonetica, 58 (1-2):
26--52 (2001)Abstract
Fundamental frequency (F0) peak delay (henceforth peak delay) refers
to the phenomenon that an F0 peak sometimes occurs after the syllable
it is associated with either lexically or prosodically. Although
peak delay has been reported for various languages, the mechanism
of its occurrence has so far remained unclear. In Mandarin, peak
delay has been found to occur regularly in the rising (R) tone but
not in the high (H) tone. The present study investigates the underlying
mechanisms of peak delay by examining its relationship with tone,
tonal context, and speech rate. An experiment was conducted to test
the possibility that peak delay may occur also in the H tone in Mandarin
if the H-carrying syllable is sufficiently shortened. Native speakers
of Mandarin Chinese recorded three types of sentences each containing
a H, a R, or a weakened H tone. The sentences were produced at three
speech rates: normal, fast and slow. Analysis of F0 contours and
peak alignment revealed that at normal speech rate, peak delay occurred
regularly in both the R and weakened H tones but only occasionally
in the H tone; at slow speech rate, peak delay continued to occur
regularly in the R tone but only occasionally in weakened H and rarely
in the H tone; at fast speech rate, peak delay occurred not only
regularly in the R and weakened H tones, but also frequently in the
H tone. Results of F0 contour alignment analysis indicate that peak
delay occurs when there is a sharp F0 rise near the end of a syllable,
regardless of the cause of the rise. The finding of this study provides
support for the view that, rather than due to actual misalignment
between underlying pitch units and segmental units, much of the variability
in the shape and alignment of F0 contours in Mandarin is attributable
to the interaction of underlying pitch targets with tonal contexts
and articulatory constraints.