Vowel duration in the Buckeye corpus

Abstract

Phonological accounts of American English [W. Labov et al., The Atlas of North American English (Walter de Gruyter, Berlin, 2006)] rely on historical and phonotactic analysis to categorize the vowels as either long (two morae) or short (one mora). The vowels of beat, bait, boot, boat, bought, bite, bout, boy are traditionally identified as long, while bit, bet, bat, book, but, bot are supposedly short. It is a reasonable question whether these vowels are indeed longer and shorter, respectively, in phonetic duration. A study of “General American” [H. A. Rositzke, “Vowel-length in general American speech,” Language 15(2), 99–109 (1939)] examined the durations of the vowels of five subjects in scripted utterances, without controlling for dialect. The findings were mostly in accord with the above categories, with the exceptions that [æ, ɑ] (bat, bot) were both phonetically long. The present study is an effort to replicate Rositzke’s on 341 425 vowel tokens in the Buckeye Corpus of conversational English (40 speakers from Columbus, Ohio). The results essentially confirm that the vowels [æ, ɑ] (bat, bot) are phonetically as long as the traditional “long” vowels. This situation calls the traditional analysis of American English vowel length into question.