An acoustic perspective on legacy data: Vowels in the digital archive of Southern speech

Speech varies widely in the American South, but the region is argued to share the Southern Vowel Shift, whose various characteristics include monophthongization of upgliding diphthongs, convergence of certain front vowels via raising and lowering, and back-vowel fronting. We investigate the influence of social factors on shift participation using vowel formant and duration data from the Digital Archive of Southern Speech (recorded 1968−1983), which is newly transcribed and segmented by forced alignment. With this corpus of 64 linguistic interviews (372 hours), we study how shifting varies in geographic space, across states from Texas to Florida. The interviews offer large amounts of data from individual speakers, and their semi-spontaneous nature reveals a more realistic portrait of phonetic variability than is typically available. Interviews of European- and African American speakers permit comparison of the Southern Vowel Shift with the African American Vowel Shift. The impacts of other factors on the vowel space are evaluated including generation, gender, socioeconomic status, and education level. Acoustic analysis of historical speech corpora offers perspective for modern sociophonetic studies, by providing a point of comparison to illuminate the development of modern regional variation, which will inform and enhance models of language change over time.