Uniformity in talker-specific phonetic realization: Evidence from sibilant fricatives in American English and Czech

•  23 February 2017
•   Eleanor Chodroff
•   PhD student, Department of Cognitive Sciences, Johns Hopkins University

The acoustic-phonetic properties of speech sounds vary substantially across languages, and even across talkers within a single language. There is, however, considerable evidence that phonetic properties that the realizations of different speech sounds do not vary independently but are highly structured (mutually predictable). Evidence for structured variation of this type can be found in the covariation of vowels in the F1xF2 plane, with talkers forming relatively congruent but shifted formant patterns, but shifted vowel spaces (e.g., Joos, 1948; Nearey, 1978), and covariation of voice onset time (VOT), as talkers primarily differ in overall mean VOT, especially among the aspirated stops [pʰ tʰ kʰ] (e.g., Chodroff & Wilson, 2017). Cases of structured variation reveal that there are constraints on phonetic variation in language- and talker-specific sound systems (e.g., Liljencrants & Lindblom, 1972).

This talk examines the predictions of two uniformity constraints that require similar (or uniform) phonetic realization of distinctive features across members of a natural class. To evaluate the predictions, I present data on the realization of sibilant fricatives across talkers of American English and Czech. The findings support the hypothesis that talker variation is highly constrained, and also have important implications for rapid perceptual adaptation to novel talkers.