11. A tale of two diphthongs in an indigenous minority language: Yami of Taiwan
This study investigates the phonological variation and sound change in the Yami diphthongs (ay) and (aw) (e.g., <i>mangay ~ mangey ‘</i>go’, <i>araw ~ arow ‘</i>day, sun’), a Philippine language spoken on Orchid Island, 60 kilometers southeast of Taiwan. Previous studies (Rau & Chang 2006; Rau & Dong 2006) found that the two diphthongs were undergoing vowel raising on the island with an isogloss separating the more progressive northeast from the more conservative southwest. However, social factors were not discussed, and thus no interpretation of the vowel raising was provided.The present study examined both linguistic and social factors accounting for vowel raising, with a goal of interpreting the indexical meanings of sound change in the two diphthongs on the island. The data were 20 narratives taken from a Yami corpus (http://yamiproject.cs.pu.edu.tw/yami), 10 narratives from Dong & Rau (1999, 2000), and word list elicitation collected in 1995. Our results from VARBRUL analyses confirmed that vowel raising is a geographical feature and that the rates of change have formed a clear isogloss separating the northeast from the southwest varieties. However, vowel raising of (ay) has progressed slightly faster than that of (aw). The preceding segments of (ay) and (aw) favoring raising are mainly determined by the feature of [continuant]. For both diphthongs, [+continuant] favors raising whereas [–continuant] disfavors it. There was stylistic variation with more raising in narrative style than in word list reading. Vowel raising was preferred by males; however, young females seem to have surpassed young males in adopting this feature in narrative style, a phenomenon corresponding to the social mobility of women. Perhaps vowel raising has ceased to be a gender marker and shifted to an ethnic identity marker.