Reduction in Dali Nisu tone change-in-progress

In this paper, reduction as a key mechanism in diachronic tone change is illustrated through an apparent-time study of tone changes-in-progress in Dali Nisu, a Tibeto-Burman minority language spoken in southwest China. 26 native speakers of Dali Nisu (11 female, 15 male) participate in a tonal production experiment. Linear mixed effects modelling results show that three reduction changes are in progress: 1) high level tone lowering, 2) low rising tone flattening, and 3) low falling tone flattening. As a result of (1) and (3), overall tonal range is decreasing. Voicing of syllable-initial consonants interact with the reduction changes: the magnitude of the reduction effect seen among younger, more educated speakers depends on voicing of the initial consonant. This case study provides a snapshot of tone change-in-progress, showing that tonal reduction is an important mechanism shaping tone change in syllable-tone languages.