Variation in the tonal space of Yangliu Lalo, an endangered language of Yunnan, China

Endangered tone languages are not often studied within quantitative variationist approaches, but such approaches can provide valuable insights for language description and documentation in the Tibeto-Burman area. This study examines tone variation within Yangliu Lalo (Central Ngwi), a minority language community in China that is currently shifting to Southwestern Mandarin. Yangliu Lalo’s Tone 4, the rising-falling High tone, is lowering and flattening among young people, especially females, who also tend to use Lalo less frequently. Tonal range in elicited speech is shown to be decreasing as use of Lalo decreases. Concurrently, the standard deviation of the pitch of individual tones also decreases, while at the same time speakers with a narrow tonal range also show greater articulatory precision for each tone. Tonal range and standard deviation of pitch are both parameters of tonal space, the arrangement of, and relationship between, tones within the tonal system. The results from our apparent-time study suggest that tonal space provides a new avenue of sociolinguistic inquiry for tone languages.