Falling diphthongs have a dynamic target while rising diphthongs have two targets: Acoustics and articulation of the diphthong production in Ningbo Chinese

Abstract

It is controversial whether diphthongs are phonologically vowel sequences and thus phonetically have two targets or diphthongs are phonologically vowel phonemes that contrast with monophthongs and thus phonetically have one dynamic target. Chinese dialects are generally known as having a rich inventory of diphthongs, and typically there are both falling and rising diphthongs. This paper is an acoustic and articulatory study on the diphthongs in Ningbo Chinese. The acoustic data are from 20 speakers and the lingual kinematic data are collected from 6 speakers by using EMA. The acoustic results show that both the onset and offset elements have comparable formant frequency patterns to their corresponding target citation vowels in a rising diphthong, but in a falling diphthong, only the onset element has a comparable formant frequency pattern to its corresponding target citation vowel whereas the offset element is highly variable. The articulatory results further reveal that diphthong onset is better controlled than diphthong offset, and more importantly, diphthong production is constrained by the general articulatory-to-acoustic relations. It is generally concluded that in Ningbo Chinese, rising diphthongs have two targets and can thus be understood as vowel sequences while falling diphthongs have only one dynamic target and should be treated as a single vowel phoneme.