Vowel mergers in the American South

This study investigates the occurrence of a series of vowel mergers in the English of the Southern United States. Investigated mergers include the pin-pen merger, which may be considered characteristic of Southern English, as well as the cot-caught, pull-pool, fill-feel, and cord-card mergers, which are less strongly identified with the region. First and second formant values of over 300,000 vowel measurements from 41 speakers were automatically extracted from.wav files contained in the Digital Archive of Southern Speech (DASS). Vowel distributions were statistically analyzed via Pillai scores, Euclidean distance, and mixed-effects modeling to determine to what degree, if any, the speakers participate in these mergers. Previous studies on vowel merger in the United States have typically classified speakers into discrete “merged” or “unmerged” categories, often relying on speaker or listener judgments to do so. The richness of the acoustic data and high number of tokens available for this study allow speakers to instead be classified along a spectrum, where they are described by “degree of merger” rather than binarily. The results in turn provide new perspective on how Southerners have participated in or resisted dialectal changes that have shaped American English from the late 18th through the mid-20th century.