Examining suprasegmental and morphological effects on constriction degree with ultrasound imaging

Abstract

Two case studies of ultrasound imaging use tongue shape differences to investigate whether suprasegmental influences affect the articulatory implementation of otherwise equivalent phonemic sequences. First, we examine whether word-medial and word-final stop codas have the same degree of constriction (e.g., "blacktop" vs. "black top"). Previous research on syllable position effects on articulatory implementation have conflated syllable position with word position, and this study investigates whether each prosodic factor has an independent contribution. Results indicate that where consistent differences are found, they are due not to the prosodic position but to speaker-specific implementation. Second, we examine whether morphological status influences the darkness of American English /l/ in comparing words like "tallest" and "flawless." While the intervocalic /l/s in "tall-est" and "flaw-less" are putatively assigned the same syllabic status, the /l/ in "tallest" corresponds to the coda /l/ of the stem "tall" whereas that of "flawless" is the onset of the affix "-less." Results indicate that /l/ is darker—the tongue is lower and more retracted—when corresponding to the coda of the stem word. Data in both studies were analyzed with smoothing spline ANOVA, an effective statistical technique for examining differences between whole tongue curves.