On what it takes to predict perceptual difficulty in cross-language vowel perception

Abstract

According to current models of cross-language speech perception and second language (L2) speech learning, perceptual difficulty depends upon how listeners map the phonetic segments of the foreign language onto their native language (L1) categories. A number of indirect methods have been suggested for predicting perceptual difficulty, e.g., contrastive phonemic analyses and acoustic comparisons of L1 and L2 sounds. This presentation summarizes recent studies which directly assessed perceptual assimilation patterns for North German vowels (as perceived by American English listeners) and for British English vowels (as perceived by Danish listeners). Vowels were produced in CVC syllables in various consonantal contexts in both citation form and sentence frames. As expected, contrastive phonemic analyses were not good predictors of assimilation patterns. Somewhat surprisingly, acoustic comparisons didn’t always predict assimilation patterns either. In particular, measures of acoustic similarity from ‘‘canonical’’ forms didn’t predict acoustic similarity for coarticulated vowels, nor did these measures predict perceptual similarity. Our results strongly suggest that perceptual difficulty in cross-language speech perception cannot be predicted using indirect methods, nor can difficulty be predicted by perceptual studies of citation form utterances. Instead, successful predictions of perceptual difficulty must be based on direct assessments of assimilation patterns. [Work supported by NIDCD.]