Measures of spectral tilt in Shanghainese stops and glottal fricatives

Abstract

Shanghainese differs from other major Chinese dialects in having a three-way contrast among stop consonants. Although phonological descriptions often label these sounds as voiceless aspirated, voiceless unaspirated, and voiced, in contemporary Shanghainese the “voiced” category is not typically produced with closure voicing in initial position. Rather, the vowel onset appears to be characterized by breathy voicing, as demonstrated by acoustic, aerodynamic, and transillumination data. Past studies have been limited to few speakers. This study presents preliminary data of a large-scale study of the Shanghainese stop system as well as the voicing contrast in glottal fricatives, another unusual feature of the language. Data have been collected from 20 male and female native speakers. Measures are made of voice onset time (for the stops), and three measures of spectral tilt (for stops and glottal fricatives): The relative amplitudes of (a) the first two harmonics (H1-H2); (b) H1 and the first formant (H1-A1); and (c) H1 and the third formant (H1-A3). Spectral tilt measures are taken at phonation onset and 50 ms into the vowel. Preliminary analyses suggest that all three spectral measures may lend insight into the nature of the source distinction among the stops as well as the glottal fricatives.