Raw acoustic vs. normalized phonetic convergence: Imitation of the Northern Cities Shift in the American Midwest

Abstract

Word shadowing tasks elicit phonetic convergence to the stimulus model talkers, suggesting a tight perception-production link. The magnitude of this convergence is affected by linguistic and social factors, suggesting that the perception-production link is mediated by higher-level phonological and social structures. The current study explored the nature of the perception-production link in an explicit comparison of raw acoustic vs. normalized phonetic convergence in word shadowing. American Midwestern participants repeated words after a model talker with features of the Northern Cities Shift vowels in one of three instruction conditions, which varied in whether participants were primed with the regional background of the model talker and in whether they were asked explicitly to imitate her. The results revealed normalized phonetic convergence to the model talker’s Northern Cities Shift vowels, even when this convergence entailed divergence from the raw acoustics, and token-by-token variability in her productions, consistent with a tight perception-production link that is mediated by linguistic structure. Modest effects of instruction condition on the magnitude of phonetic convergence were also observed, consistent with social information mediating this perception-production link. The results of this study provide converging evidence for phonetic convergence that is both phonetically-detailed and subject to constraint by higher-level representations.