The 157th Meeting of Acoustical Society of America in Portland, Oregon, May 21, 2009 4pSW35. Confusion Direction Differences in Second Language Production and Perception Yen-Chen Hao & Kenneth de Jong (yehao@indiana.edu & kdejong@indiana.edu) Department of Linguistics, Indiana University Main Points Second language learners may display opposite confusion directions in perception and production. L2 learners may show different error patterns in different prosodic locations due to the allophonic variation in the target language. Old category bias is only observed in production-related tasks. Category bias in perception and production Frequency biasing In perceptual identification by native speakers, response bias typically correlated positively with segment frequency (Silbert & de Jong, 2007). Second language learners should be biased towards L2 old categories since they occur more frequently (both in L1 and L2) than the new categories (only in L2). Novel Category bias de Jong et al. (2008) found that L2 learners were biased towards old categories in production-related tasks (Reading and Mimicry), but biased toward novel categories, or not biased at all, in perceptual identification. Question How does allophonic variation induced by different prosodic locations affect bias patterns? Discussion L1-L2 category mismatch Korean EFL learners have more problems with the allophonic variation in post-stress position, which mismatches the L1 categories. Post-stress position induces larger variation in bias than pre-stress position. Discrepancy in perception and production Korean learners displayed different directionality of post-stress errors in perception and production In perception-related tasks (Identification and Mimicry), learners made more voiceless  voiced errors. In the production task (Reading), learners made more voiced  voiceless errors. Identification Reading Old-New category bias In Identification, learners have little bias towards old (stops) and new (fricative) categories. In production-related tasks (Reading and Mimicry), learners are more biased towards the old categories (stops). Methods Participants -20 Korean learners of English -Undergraduates (22-28 years; 15 F, 5 M) in Gyeonggi Korea (near Seoul) -Traveled 3 months or less in English- speaking areas Stimuli -10 English anterior obstruents Similar to L1 (Old): /p, b, t, d, s/ Not similar to L1 (New): /f, v, θ, ð, z/ -Two contexts: /aCá/ & /áCa/ -Produced in isolation by 4 Midwestern American speakers (2 male, 2 female) Results Bias in Identification Large variation in bias parameter in the post- stress context. Post-stress position exhibits more bias towards the voiced obstruents. Bias in Mimicry Post-stress: bias towards the voiced Bias in Reading Variation along the post-stress dimension Post-stress: bias towards the voiceless /áCa/ /aCá/ Orthographic /p/ prompt Evaluation /p/ Tasks Identification (Id) Participants identified the obstruents from a set of 15 response options (plus “Other ____”). 2. Mimicry (Mim) Participants listened to the stimuli and repeated after each one. 3. Reading (Rd) Participants read same list of forms as American speakers who produced stimuli. Evaluation 10 English native speakers judged each of the productions from Tasks 2 and 3 using similar response options as in Task 1. Analysis Similarity Choice Model Bias parameters (Luce, 1963), estimates of an overall tendency for a particular category to be used, were calculated for each segment English talker /áCa/ English judge /áCa/ /áCa/ Production [p] Production [b/p’] Korean listener /aCa/ Korean talker /aCa/ Allophonic variation in English and Korean (hypothetical) English Pre-stress /aCá/ Identification /b/ response Orthographic /b/ prompt /aCá/ - Voicing + Post-stress /áCa/ /áCa/ References De Jong, K., Hao, Y-C., Park, H., & Silbert, N.H. (2008). The ‘[English]’ effect in acquisition of English as a second language: Novel-category biases in second language perception and production. JASA, 123: 3332, 2pSCc53. Luce, R. D. (1963). Detection and recognition. In R. D. Luce, R. R. Bush, & E. Galanter (Eds.), Handbook of Mathematical Psychology (pp. 103-189). New York: John Wiley & Sons. Silbert, N.H., and K. J. de Jong (2007). Response Bias, Type and Token Frequency, and Prosodic Context in Segment Identification. JASA, 122:3019, 3aSCa15. Korean Intervocalic /aCa/ - Voicing + Acknowledgments We thank Mi-Hee Cho for her help in collecting the consonant data, and Noah Silbert, and Kyoko Nagao for their work on the design, analysis, and processing of the data. Work supported by the NSF (grant #BCS-04406540). /aCá/ - Voicing +