Neutral Tone as a Window into Tonal Reduction: Context, Duration, and Prosodic Structure across Speech Styles
Jingyi Sun (LPP)
The Mandarin neutral tone (NT) provides an empirical window into how tonal reduction operates under prosodic and temporal constraints. Based on a 26-hour corpus of spontaneous and read Mandarin, this talk investigates how NT contours arise from the interaction of tonal context, duration, and grammatical structure. Results show that NT is not a toneless residue but a dynamic prosodic unit whose pitch contour unfolds with temporal availability. NT remains in the lowest register after Tone 3 but is consistently raised when followed by Tone 3, even in ultrashort durations (~40 ms), revealing early activation of low-tone gestures rather than post-lexical interpolation. Gender and grammatical subtype further shape this reduction system: female speakers and /ən/-type plurals maintain wider pitch ranges and greater tonal dynamics, while /ə/-type particles undergo stronger temporal compression. These hierarchical patterns remain stable in spontaneous speech. These results demonstrate that NT realization reflects a dynamic process of tonal integration, compatible with the mechanisms proposed by the Stem-ML framework (Kochanski & Shih, 2000; 2003), operating even under significant temporal and articulatory constraints.
Inspecting monophthongization: a corpus-based study of Mandarin /ai/ reduction across speech styles and vowel durations
Yunzhuo Xiang (LPP)
Monophthongization is widely attested across the world’s languages. In Modern Mandarin, the diphthong /ai/ has undergone monophthongization to /ɛ/ or /æ/ in many regional varieties. This study investigates the diachronic /ai/ > /ɛ, æ/ change through an analysis of synchronic variation. Based on the corpus of Jingyi Sun et al. (2024), we modelled F1 and F2 variation in the Standard Mandarin /ai/ across different vowel durations and speech styles using generalized additive mixed models (GAMMs). The results indicate that speech style and vowel duration influence not only vowel target frequencies but also the degree of formant movements. We further consider that the monophthongization /ai/ > /ɛ, æ/ may be accounted for in terms of spectral dynamics along the dimension of hyper- and hypo-articulation, precisely, as the phonologization of the hypo-articulated diphthong /ai/.