Acoustics of the creaky phonations in Yateé Zapotec

Abstract

Yateé Zapotec (YZ) is a variety of Zapotec spoken in San Francisco Yateé, Oaxaca, Mexico. The language has three phonation types: modal, checked, and rearticulated. Checked and rearticulated phonations both involve glottalization realized on vowels but differ in the phasing of the glottalization in vowels. Checked phonation has late-phased glottalization whereas rearticulated phonation is characterized by mid-phased glottalization. Previous studies on the phonetics of Zapotec phonations seldom compare the phonations in the time domain. In this study, we compare the spectral tilt, degree of noise, amplitude of voicing, and duration of the three phonations over the time course of vowels. Using multi-dimensional scaling analysis, we also find that the amplitude dip in the middle of the vowels (induced by glottalization) differentiates rearticulated vowels from modal and checked vowels, while the shorter duration differentiates checked vowels from modal and rearticulated vowels. We conclude that in YZ, mid-phased glottalization is the defining feature of rearticulated phonation whereas duration is the defining feature of checked vowels. Future studies can test whether YZ listeners are also more sensitive to amplitude dip and short duration when perceiving rearticulated and checked vowels.