Abstract:
The perceptual assimilation model (PAM) [Best et al., JEP: HPP 14, 345--360 (1988)] posits that perception of non-native contrasts is constrained by experience with both the phonological functions and the phonetic details of familiar native contrasts. Adults' discrimination of an unfamiliar contrast depends not only on whether its members resemble a known phonological contrast, but also on perceived ``goodness of fit'' to native phonetic categories. Adult findings support PAM's prediction that perceptual assimilation of contrasting non-native consonants or vowels to a single native category yields poorer discrimination than assimilation to two categories (TC contrasts). Discrimination is worst if both phones are equally similar to a single category (SC), substantially better if they differ in category goodness (CG), near ceiling for TC assimilations. PAM predictions have focused on adults' first encounters with unfamiliar contrasts. However, non-native speech perception also provides a window on infants' emerging knowledge about phonetic details and phonological organization in native speech. Native phonetic experience influences discrimination of unfamiliar non-native contrasts by 10 months, but systematic phonological knowledge is not evident until later. PAM can also be extended to phonetic and phonological aspects of second language (L2) learning developmentally. [Work supported by NICHHD and NIDCD.]