F₀ of the Cantonese tones in the intonational contexts

This study investigates the F0 contours of the nine Cantonese tones, [55] [33] [22] [21] [25] [23] [5] [3] [2], in contexts of the declarative and interrogative intonations. Four young adult speakers, two male and two female, uttered the test monosyllabic words associated with the nine Cantonese tones in the carrier sentence, [lei55 kɔ33 tsi22 tʊk2 ___ ] (‘This word (is) uttered (as) __’), of the declarative and interrogative intonations. Three repetitions of the test sentence of each intonation were recorded of the speakers for F0 analysis. Results show that between the declarative and interrogative intonations there are noticeable differences in the F0 contour of the sentence-final tone. The F0 contours of all the nine tones on the sentence-final syllable in the declarative context turn into rising in the interrogative context. The degree of the F0 upward deflection, which varies according to the tone type, is largest for the non-high long tones, [33] [22] [21] [25] [23], followed by the non-high short tones, [3] [2], and then the high tones, [55] [5], in a decreasing order. The difference in F0 contour among the various tone types in the declarative context is therefore reduced as a result of the effect of the imposing rising F0 contour in the interrogative context. This is particularly obvious for the tones, [33] [22] [21] [23], where the second halves of their rising F0 contours become closely similar in the interrogative context. Furthermore, the entire F0 range encompassing all the nine tones is expanded and the F0 levels of the nine tones are raised in the interrogative context compared to the declarative context. As for the durations of the tones on the sentence-final syllable, they are lengthened in the interrogative context compared to those in the declarative context, though it is less marked for the high tones, [55] [5]. Despite the change in duration, the proportional difference in length between the long and short tones is maintained in the interrogative context. In conclusion, the F0 contours of all the nine Cantonese tones become similar in the interrogative context, losing the inherent F0 contrasts found in the declarative context.