Pitch pattern variations in three regional varieties of American English

This acoustic study explored dialect effects on realization of nuclear pitch accents in three regional varieties of American English spoken in central Ohio, southeastern Wisconsin and western North Carolina. Fundamental frequency (f0) change from vowel onset to offset in the most prominent syllable in a sentence was examined along four parameters: maximum f0 change, relative location of f0 maximum, f0 offset and f0 fall from maximum to offset. A robust finding was that the f0 contours in the Southern (North Carolina) variants were significantly distinct from the two Midwestern varieties whose contours did not differ significantly from one another. The Southern vowels had an earlier f0 rise, a greater f0 fall and a lower f0 offset than either Ohio or Wisconsin vowels. There was a sharper f0 drop preceding a voiceless than a voiced syllable coda. No significant dialect-related differences were found for flat f0 contours in unstressed vowels, which were also examined in the study. This study contributes the finding that dynamic variations in pitch are greater for vowels which also exhibit a greater amount of spectral dynamics. The interaction of these two sets of cues contributes to the melodic component associated with a specific regional accent.