Coarticulation of Sibe Vowels and Dorsal Fricatives in Spontaneous Speech: An Acoustic Study

Previous phonological analyses of dorsal segments in Sibe (Tungusic; Xinjiang, China) have treated the velar and uvular series as allophonic, with velar segments adjacent to /i ə u/ and uvular segments adjacent to /a o/. In this paper, we use a spontaneous speech corpus to examine the acoustic correlates of coarticulation of dorsal fricatives and vowels in Sibe. The first two spectral moments and mid-frequency spectral peak of dorsal fricatives were measured over the fricative onset in VC sequences and offset in CV sequences. Differences in spectral measures suggest that dorsal fricatives coarticulate with both preceding and following vowels primarily in terms of tongue dorsum backness, but with some role of height possible. These findings reflect a more complex relationship between Sibe vowels and dorsals than previously described; the distribution of labels used for the dorsal fricatives also suggests a gradient assimilation process.