Relative cue weighting in production and perception of an ongoing sound change in Southern Yi

Multiple co-varying cues for a phonological contrast are often introduced by coarticulation, and sound change occurs when their relative weighting shifts. The central issues for this kind of sound change include how cue weighting shifts over time in both production and perception and what the mapping is between production and perception during this process. This study aims to provide insights to these questions by examining an ongoing change in the tense vs. lax register contrast in Southern Yi. Production and perception experiments were conducted with the same group of speakers to evaluate the relative importance of the source cue (i.e., phonation) and its coarticulated cues (i.e., vowel formants and f0) for this contrast. While speakers of all age groups still maintain the register contrast, our results show that formant differences are overtaking phonation as the primary cues. This sound change is more advanced in non-high vowels than high vowels in both perception and production. Moreover, production and perception are misaligned; in both cases, the shift to formant values occurs first in perception, with production lagging behind. These findings illustrate the nuanced progression of sound change and a better understanding of the role of production and perception in the initiation of a sound change.