| This dissertation is an investigation of acoustic properties of lexical tone in two dialects of Dane-z&barbelow;aa (Athabaskan). The noteworthy mirror-image tone systems of the H-marked Doig and L-marked Halfway dialects provide a unique opportunity to explore intrinsic differences in how pitch manifests in specific environments.;The dissertation has three main parts. The first explores effects of various linguistic features on normalized pitch, including tone, lexical and morphological categories. Tone was found to be statistically robust in Halfway, and less so for Doig, indicating that the distinction between tonal categories in Doig is becoming less stable.;The second part investigates effects of word-final glottal stops on the voice quality of preceding vowels, in comparison to vowels of the same quality in open syllables. Measures used include intensity, pitch, jitter, and spectral tilt. Expected outcomes of lower intensity and increased jitter in vowels before word-final glottal stops were revealed for both dialects. Results for pitch garnered a lack of a significant effect of word-final glottal stops for the Doig speakers, where a pitch raising effect was expected. These findings offer evidence that Doig is changing from a language that originally had pitch raising as a reflex of the PA constriction, to one in which the trigger for marked tone is no longer manifesting in a measurable way, with respect to pitch. Halfway speakers showed the expected pitch lowering before the word-final glottal stop.;The third part explores effects of speech styles on normalized pitch, specifically looking at word list and narrative data of two speakers of the Doig dialect. Results showed that within a given speech style both speakers faithfully retained the difference between H and L tone categories. One speaker used both language-internal and language-external cues (eye-gaze and gesture) to mark difference in style, while the second speaker relied upon neither. If one were to consider a broader landscape of style, beyond linguistic cues, it is possible to understand that speakers may draw from a larger repertoire to signify differences in speech style, although it is not necessary in order for a speaker to remain faithful to the communicative event. |
