Evidence for three-level vowel length in Ageer Dinka

Three-level vowel length is typologically unusual, and the supporting evidence is limited (Odden, 2011). One of the most compelling hypothesized cases for this configuration is Dinka, a Western Nilotic language. This paper expands the evidence base for Dinka, through an acoustic study of the Ageer dialect. Ageer is geographically distant from the Agar dialect, for which three-level vowel length was first postulated in Dinka (Andersen, 1987). It is also distant from the Luanyjang and Bor dialects, on the basis of which this hypothesis was tested acoustically. The results corroborate the three-level vowel length hypothesis for Dinka: lexical and morphological quantity condition a salient three-way split in vowel duration. Coda duration and vowel quality do not reveal comparable differences.