https://www.selleckchem.com/products/solutol-hs-15.html Regional variation in American English speech is often described in terms of shifts, indicating which vowel sounds are converging or diverging. In the U.S. South, the Southern vowel shift (SVS) and African American vowel shift (AAVS) affect not only vowels' relative positions but also their formant dynamics. Static characterizations of shifting, with a single pair of first and second formant values taken near vowels' midpoint, fail to capture this vowel-inherent spectral change, which can indicate dialect-specific diphthongization or monophthongization. Vowel-inherent spectral change is directly modeled to investigate how trajectories of front vowels /i eɪ ɪ ɛ/ differ across social groups in the 64-speaker Digital Archive of Southern Speech. Generalized additive mixed models are used to test the effects of two social factors, sex and ethnicity, on trajectory shape. All vowels studied show significant differences between men, women, African American and European American speakers. Results show strong overlap between the trajectories of /eɪ, ɛ/ particularly among European American women, consistent with the SVS, and greater vowel-inherent raising of /ɪ/ among African American speakers, indicating how that lax vowel is affected by the AAVS. Model predictions of duration additionally indicate that across groups, trajectories become more peripheral as vowel duration increases.Four self-identified code-switchers from Southwest Virginia and six actors who did not identify as having Southern accents each recorded two sets of stimuli in which they aimed to produce a more Southern and a more Standardized US accent. An analysis of the Voice Onset Time (VOT) of phrase and word initial voiced stops revealed that both groups of speakers produced more tokens with prevoicing (lead or negative lag voicing) when speaking in the Southern versus the Standard guise, and that in the Standard guise, the Southern speakers produced mor