The Interaction Between Tone and Duration in Du’an Zhuang

Abstract This research investigates the tone system of an understudied language, Du’an Zhuang and its interaction with duration. Cross-linguistically, tones tend to be less complex in shorter duration contexts. In Du’an Zhuang, syllable type provides these contexts: There are six contrastive tones among unchecked syllables with longer rhyme duration, but this is reduced to four tones in shorter duration checked syllables. Acoustic analyses of f0 and duration from six native speakers were performed to check whether tonal complexity is reduced in the shorter duration checked syllables. The results showed this was true with some exceptions. The two tones in CVVO syllables corresponded to the two least complex tones; however, one of the two CVO tones included a more complex rising tone. This rising tone exhibited a reduced f0 excursion though. Finally, there is a two-way phonological vowel length contrast in Du’an Zhuang, which necessarily interacts with syllable type via its effect on rhyme duration. However, based on our vowel duration measurements, this vowel length contrast only exists in unchecked syllables with sonorant codas, the only syllable type where rhyme duration and vowel duration could possibly differ. In this context, a sonorant coda contributes to the syllable’s rhyme duration, but not to vowel duration, allowing syllable type and vowel length to contrast independently, only in this phonological context.