Acoustic characteristics of vowels in three regional dialects of American English

Most of the comparative sociophonetic studies of regional dialect variation have focused on individual vowel differences across dialects as well as speaker variables. The present work seeks to define basic acoustic characteristics of entire vowel systems for three different regional variants of American English spoken in southeastern Wisconsin (affected by the Northern Cities Shift), western North Carolina (affected by the Southern Vowel Shift), and central Ohio (not considered to be affected currently by any vowel shift). Three groups of speakers (men and women) aged 20–29 years were recorded from each geographic area defined by two to three counties (creating a highly homogeneous set of speakers). Acoustic measures for the set of 14 monophthongs and diphthongs in /h—d/ context included vowel space area for each speaker, global spectral rate of change for diphthongized vowels (defined over the first three formant slopes), the amount of frequency change for F1 and F2 at two temporal points located close to vowel onset and offset (vector length), and vowel duration. These measures will establish both systemic and vowel inherent characteristics across the three dialects, serving as a basis for future examination of conditioning factors on vowels in chain shifts. Dialectal differences will be discussed. [Work supported by NIH NIDCD R01 DC006871.]