The acoustic realization of vowels of Shanghai Chinese

This study aims to understand the phonological vowel inventory and the phonetic implementation of vowel categories in Shanghai Chinese by examining the acoustic realization of two complementary sets of vowels in the language, one set appearing in open syllables (OSVs) and the other in closed syllables with a glottal coda (CSVs). Two factors—consonant onset and prominence level—were controlled. Results confirmed that OSVs were longer than CSVs (by an average factor of 1.5) and were realized with a more expanded acoustic vowel space. Detailed analyses of the vowel formant data suggested that CSVs cannot be the reduced realization of OSVs. Instead, the seemingly spectral reduction of CSVs is an inherent feature of the vowel's phonetic implementation, in contrast to the more static spectral patterns of the OSVs. Such a spectral change of CSVs is proposed to be a speaker-controlled process, the purpose of which is to maximally differentiate CSVs from OSVs, the two sub-systems of the vowels of the language.