Dialectal variation in the perception of phonological contrasts

The present study examined the cross-dialectal variability in perceptual patterns of the alveolarretroflex contrast, a critical feature often used to differentiate Beijing Mandarin from other dialects of Mandarin, such as Taiwan Mandarin. While previous research has focused on dialectally and contextually driven variation in alveolar and retroflex productions, little is known about whether similar variability is also present in perception. We investigated the categorical and gradient modes of alveolar-retroflex perceptions in different vowel contexts by listeners from Beijing and Taiwan. The results indicate that that Beijing and Taiwan listeners have different perceptual boundaries along the acoustic continuum, with a lower cutoff frication frequency required for the retroflex percepts for Beijing listeners. Both groups of listeners’ category boundaries shift to lower frequencies in the rounded vowel context to normalize for vowel coarticulatory effects. Discrepant within-category sensitivity was found in that while both Beijing and Taiwan listeners perceived all retroflex variants as equally good exemplars, Beijing listeners considered the endpoint variant of the alveolar as the preferred category exemplar. We concluded an articulatory explanation for this asymmetrical within-category discriminability and also discussed the findings with respect to the hyperspace effect in perception. Together, our results show that linguistic (i.e., vowel context) and sociolinguistic (i.e., dialect) factors collectively and variably affect the perception of the Mandarin alveolar-retroflex contrast.