An acoustic study of coarticulation: consonant-vowel and vowel-to-vowel coarticulation in four Australian languages

© 2012 Dr. N. Simone GraetzerAcoustic phonetic experiments were conducted with the aim of describing spatial coarticulation in consonants and vowels in four Australian languages: Arrernte, Burarra, Gupapuyngu and Warlpiri. Interactions were examined between coarticulation and factors such as consonant place of articulation (the location of the point of maximal consonantal constriction in the vocal tract), the position of the consonant relative to the vowel (preceding or following), prosodic prominence and language. The principal motivation was to contribute to the experimental literature on coarticulation in Australian languages, given their unusual phonological characteristics. The results of acoustic measurements show that in stop consonant and vowel production, there are systematic contrasts between consonant places of articulation, especially between peripheral (i.e., bilabial and dorso-velar) and non-peripheral categories, and there are clearly discernible consonant place-dependent differences in the degree of vowel-to-consonant and consonant-to-vowel coarticulation. Additionally, consonant place of articulation is seen to strongly modulate vowel-to-vowel coarticulation. As observed in other languages, such as Catalan, Italian and German, the degree of vowel-to-consonant coarticulation is seen to vary inversely with the degree of consonantal articulatory constraint (i.e., degree of tongue dorsum raising), as does the degree of segmental context-sensitivity. However, findings reported in this dissertation suggest that, unlike results reported previously for European languages such as English, anticipatory vowel-to-consonant coarticulation tends to exceed carryover coarticulation in these languages. With regard to prosodic effects on coarticulation, it appears that prominent vowels do not typically undergo localised hyper-articulation or acoustical expansion as in English, Dutch and German. It is concluded that these results support the view that the maintenance of consonant place of articulation distinctions is pre-eminent in Australian languages. The analyses that are presented contribute to an understanding of the role of consonant place of articulation in coarticulation and, more generally, of the relationship between the acoustics and the biomechanics of speech