Centering diphthongization in Hui Chinese dialects

This paper reports centering diphthongization in three Hui Chinese dialects. It argues that centering diphthongization serves as clear evidence that monophthongs and diphthongs are not a dichotomy, but a continuum, and thus supports a dynamic theory of vowel production (Hu, 2017). Centering diphthongs in Hui dialects occur as an intermediate vowel category between monophthongs and diphthongs. Fine-grained phonetic details reveal that the process of centering diphthongization is gradient in the three Hui dialects. The Yi county dialect is at an early stage: centering diphthongization is essentially a phonetic process of adding an additional neutralized [ɐ]-like production to the distinctive vowel element, namely [i u y e o] > [i:ɐ u:ɐ y:ɐ e:ɐ o:ɐ], respectively. The Qimen dialect is at a phonologically developed stage: monophthongs and diphthongized vowels contrast in dynamics, namely the static [i u y] versus the dynamic [i:ɐ u:ɐ y:ɐ], but diphthongized vowels have a temporal structure different to that of plain diphthongs. The Xiuning dialect is at a final stage: monophthongs and diphthongized vowels contrast in dynamics, and diphthongized vowels exhibit a temporal organization similar to that of plain diphthongs.