Invariance of Relative F_0 Change Field of Chinese Disyllabic Words

摘要

In automatic voice response systems where a large number of words are inserted into fixed sentences, such as in voice-guided car navigation systems, one of the most important problems is the adjustment of the fundamental frequency (F_0) contour of the inserted word to suit the F_0 context of the fixed sentence. The effects of intonation and tone on the F_0 contours of Chinese words can be described in terms of a word-level F_0 range (WF_0R) and an F_0 change field (F_0CF). WF_0R in any position of a sentence is a tone-independent general F_0 range, whereas F_0CF is an F_0 range taking the tone combination of words into account. Relative F_0CF is regulated in reference to WF_0R. If WF_0R is used to represent the declination of a sentence, the relative F_0CF should be invariant but dependent on the tone combination of a word. This paper examines the invariance of the relative F_0CF among individuals. From an analysis of four native speakers' utterances of 160 words in the initial, middle and final parts of three carrier sentences, conducted over 2 days, we show that: (1) Chinese speakers read words in the same sentence position with stable relative F_0 change; (2) the relative F_0CFs in the middle position of a sentence are generally the same as those in the initial position, but slightly different from those in the final position; and (3) the relative F_0CFs reveal that the effects of tone on F_0 contour is individual independent.