ISCA Workshop on Plasticity in Speech Perception (PSP2005)
Senate House, London, UK
In current models of second language (L2) phonological acquisition such as Flege's Speech Learning Model (SLM) or Best's Perceptual Assimilation Model (PAM), correct category formation for L2 sounds is largely conditioned by the ability of L2 learners to perceive non-native phonological contrasts, which is viewed as a necessary attainment in the development of phonological competence. This paper reports on the results of a study designed to investigate the effect of L2 lexical knowledge on the perception of non-native phonemic contrasts. An AX minimal-pair auditory discrimination task was used to test the ability of a group of bilingual Spanish/Catalan advanced learners of English (N=74) to perceive 9 phonemic contrasts in English words and nonwords (a control group of 10 English native speakers provided base-line data). The test contained 144 aural stimuli consisting of 108 minimal pairs and 36 distractors, i.e. two realizations (non-identical tokens) of the same word, 50% of which were English nonwords. The non-native phonemic contrasts were chosen according to their relative difficulty for Spanish/Catalan learners of English, as predicted by Best's perceptual assimilation model (PAM). Real-word pairs and nonword pairs were matched with respect to phonological contrast and phonetic environment, randomized and presented to listeners with an interstimulus interval of 1 second between members of a word pair and 3 seconds between word pairs. A lexical knowledge post-test was used to assess the subjects' knowledge of the English words and nonwords in the auditory discrimination task. The subjects were asked to listen to a token of a word or nonword and decide whether they knew the item by ticking one of three options: 'yes', 'no', 'not sure'. Their knowledge of all items was further tested by means of a multiple-choice vocabulary translation test. An analysis of the scores on the perception and lexical knowledge tests revealed that advanced learners of English were more successful in perceiving non-native phonemic contrasts in known words than in nonwords. It was only with those phonemic contrasts that were harder to perceive, however, that the subjects' scores on the auditory discrimination task produced statistically significant differences between known words and nonwords. These results suggest that lexical knowledge is a significant factor conditioning the perception of nonnative phonemic contrasts, a factor to be taken into account when assessing learners' perceptual ability in the L2.
Bibliographic reference. Mora, Joan C. (2005): "Lexical knowledge effects on the discrimination of non-native phonemic contrasts in words and nonwords by Spanish/catalan bilingual learners of English", In PSP2005, 43-46.