Voice quality and tone as independent dimensions of contrast in Dinka

Languages with independently contrastive Voice Quality and Tone are rare, and the evidence base on them is limited. As a result, key hypotheses on how their phonetic realizations interact with one another and with the vowel system remain tentative. Against the background of this evidence base, it is worthwhile to conduct a production study in which Voice Quality, Tone, and Vowel Quality are orthogonally crossed. This paper presents the results of a comprehensive acoustic study on this configuration in Dinka (Nilo-Saharan, South Sudan). The study is based on 29 four-member minimal sets for Voice Quality (Modal vs. Breathy) and Tone (Low vs. High), across all seven of the Dinka vowels (/i, e, ɛ, a, ɔ, o, u/). These materials were elicited from eight speakers of the Bor South variety of Dinka. The results indicate that Voice Quality, Tone, and Vowel Quality each have their own primary correlate: phonation, F0, and formants, respectively. In addition, each distinction influences other phonetic parameters to a lesser extent. Importantly, the Voice Quality contrast is realized saliently on vowels in Low- and-High-toned syllables alike, and across the vocalic domain.