Phonetic convergence across multiple measures and model talkers

This study consolidates findings on phonetic convergence in a large-scale examination of the impacts of talker sex, word frequency, and model talkers on multiple measures of convergence. A survey of nearly three dozen published reports revealed that most shadowing studies used very few model talkers and did not assess whether phonetic convergence varied across same- and mixed-sex pairings. Furthermore, some studies have reported effects of talker sex or word frequency on phonetic convergence, but others have failed to replicate these effects or have reported opposing patterns. In the present study, a set of 92 talkers (47 female) shadowed either same-sex or opposite-sex models (12 talkers, six female). Phonetic convergence was assessed in a holistic AXB perceptual-similarity task and in acoustic measures of duration, F0, F1, F2, and the F1 x F2 vowel space. Across these measures, convergence was subtle, variable, and inconsistent. There were no reliable main effects of talker sex or word frequency on any measures. However, female shadowers were more susceptible to lexical properties than were males, and model talkers elicited varying degrees of phonetic convergence. Mixed-effects regression models confirmed the complex relationships between acoustic and holistic perceptual measures of phonetic convergence. In order to draw broad conclusions about phonetic convergence, studies should employ multiple models and shadowers (both male and female), balanced multisyllabic items, and holistic measures. As a potential mechanism for sound change, phonetic convergence reflects complexities in speech perception and production that warrant elaboration of the underspecified components of current accounts.