Assimilation and discrimination of Canadian French vowels by English-speaking adults

Abstract

According to the Perceptual Assimilation Model (PAM) discriminability of non-native contrasts depends on the perceived similarity to native phonetic categories [Best (1994)]. With respect to vowel contrasts, it has been claimed that PAM predictions hold so long as context-specific realizations of a given contrast are considered [Strange et al. (2001); Levy (2002)]. To further assess these claims, English adults were tested on perception of Canadian French tense high vowels, /i/, /y/, /u/ and their respective context-conditioned variants [I], [Y], and [U]. Adults completed 2 tasks with both citation and sentence context stimuli; stimuli for both tasks were natural /bVs/ tokens, produced by male and female talkers. For each vowel, subjects completed an identification and rating task (using English vowel response categories) which provided data to assess the assimilation pattern for four non-native contrasts: /i-y/, /y-u/, /I-Y/, and /Y-U/. Discrimination was assessed for each contrast using a categorical AXB task, in which each token is produced by a different talker. The ability to predict discrimination differences from assimilation data was assessed. The findings were examined together with acoustic analysis to determine whether acoustic differences and assimilation differences are equally predictive of relative discriminability.