Prosodic Effects on Spoken Word Recognition in Second Language:Processing of Lexical Stress by Korean-speaking Learners of English DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Jeonghwa Shin, M.A. Graduate Program in Linguistics The Ohio State University 2012 Dissertation Committee: Prof. Shari R. Speer, Advisor Prof. Mary E. Beckman Prof. Cynthia G. Clopper c Copyright by Jeonghwa Shin 2012 ABSTRACT Prosody, the melody and rhythm of speech, is known to influence how listeners inter- pret the sequence of sounds, syllables, and higher order organizational units and thus how lexical access proceeds during spoken word recognition. The present study explores how language-specific variation in prosodic structure affects L2 learners’ processing of prosodic categories during spoken word recognition. Specifically, the study examines how Korean- speaking learners of English use English lexical stress during spoken word recognition. English employs stress reliably at the lexical level. Utterances often put pitch accents on lexically stressed syllables and most lexically unstressed syllables contain reduced vowels. In contrast, Korean as a first language (L1) has neither lexical-level stress, nor reduced vowels, but instead has phrase-level prosodic structure ((T)HLH %) (Jun, 1993). Utterances often align the melody of the accentual phrase - a sequence of phrase-initial tone before a high tone - with the beginning of each content word. The phrase initial tone, T, is realized as either high (H) or low (L) tone depending on the phonation type of the initial consonant (tense/aspirated vs. lax). H is realized with a relatively high fundamental frequency (f0) and L with a relatively low f0. The Perceptual Assimilation Model (PAM; Best, 1995) predicts that if the relevant L2 sounds have no corresponding categories in L1, as is the case with the English lexical stress contrast for Korean learners of English, discrimination of the two sounds should be good because the discrimination is less strongly affected by native phonological equivalence classes. However, this prediction was not borne out in ii a preliminary eyetracking study (Shin, 2008). In Shin (2008), native English speakers, but not Korean-speaking learners of English were able to use lexical stress information during English spoken word recognition. Post-hoc analyses showed that Korean learners of English were good at identifying H-pitch accented trochaic words, but were poor at identifying iambic words that began with what they heard as aspirated sounds, suggesting that Korean phrase level prosodic structure might have constrained processing of English lexical stress in Korean learners of English. In the present study, an eyetracking experiment examined the role of both word-initial phonation type and vowel reduction in unstressed syllables in the processing of English lex- ical stress during spoken word recognition. Results showed that both native English speak- ers and Korean learners of English used the reduced vowel cue to identify target words, initiating lexical activation during the initial syllable of words. Still, Korean L2 learners had relatively delayed processing for iambic word recognition. The effect of aspirated vs. lax word-initial segment on the processing of lexical stress during word recognition was not supported statistically. However, we could observe that aspirated initial sounds particularly facilitated H-pitch accented trochaic word recognition in Korean L2 learners of English. A cross-modal gating experiment further investigated this processing difficulty by focusing on the effects of phonation type on the perception of English lexical stress without the re- duced vowel cue. This gating experiment showed very similar results to the preliminary eyetracking experiment, suggesting word-initial phonation type influences the perception of English lexical stress in Korean L2 learners of English, but that iambic stress poses gen- eral processing difficulty to Korean speakers. These findings suggest that L1 experience with both lexical processing strategy and relevant acoustic phonetic cues influences the perception and processing of L2 prosodic units during spoken word recognition. iii To my parents, who are always praying for me. iv ACKNOWLEDGMENTS During my doctoral years at OSU Linguistics, I had many people around who helped me to complete the Ph.D dissertation from various sides. I first want to express my gratitude to my advisor, Dr. Shari Speer. She has supported and guided me with endless advice, read numerous drafts, and helped me through to the end. I also want to send my special thanks to my committee members, Dr. Mary Beckman, for sharing her insights, knowledge, and enthusiasm in linguistics which gave me a big inspiration in the study of linguistics and Dr. Cynthia Clopper, for giving invaluable comments and stimulating discussions, and for believing in me and my work in the rough times. I’m grateful to Dr. Dan Mirman, Dr. Florian Jaeger, and Alex Fine who helped me with their time and expertise in statistical approaches to eyetracking data analysis. Thanks to Dr. Mark Pitt for providing helpful instructions about nonword construction. Dr. Ann Bradlow and Dr. Ewa Jacewicz were also of great help with clear and fast responses to my questions about vowel space mea- surement. Dr. Kiwako Ito introduced me to eyetracking methodology and gave helpful comments on the eyetracking data analysis. Ping Bai wrote many perl scripts to convert raw gaze data into analyzable data set. I do also thank Dr. JJ Nakayama who was pleasantly on the reading committee for my doctoral candidacy exam. Liz McCullough, Sarah Bibyk, and Laurie Maynell gave generously of their time for my stimulus recordings. Ross Me- tusalem, Sharon Rose, Stephen Boxwell helped me with ToBI transcription of the stimuli. Joeseph Marulli helped me with Praat scripts and English transcription. Ronnie Rigdon v and Ashley Coolman finished English production accuracy judgment and transcription on time. DJ Hovermale and Jon Dehdari provided LATEX help and troubleshooting. Thanks to Kodi Weatherholtz for proofreading and also for getting me off from heavy work and mind with good energy. Jeff Holliday also proofread three chapters of my dissertation. I also wish to express my appreciation to the wonderful people in Linguistics at the Ohio State University for providing me with a friendly and stimulating work environment. Lastly, I’d like to thank Dr. Kyung-Ja Park and Dr. Ranghyeyoon Kim at Korea Uni- versity for their constant support and encouragement with belief in me. Most importantly, I thank with my whole heart to my parents, sisters, and our human-like dog, Bokdol, in Korea for their unquestioning support and love. Remaining errors, inconsistencies, and flaws in the dissertation are my own. vi VITA 2000 . B.A., English Language and Literature, Korea University, South Korea 2003 . M.A., English Language and Literature, Korea University, South Korea PUBLICATIONS Conference Papers and Books Shin, J. and Speer, Shari R. (2012). English Lexical Stress and Spoken Word Recognition in Korean Learners of English. In Proceedings of the Speech Prosody 2012. Shanghai, China Shin, J. and Speer, Shari R. (2009). Processing of Lexical Prosody in L2 Word Recogni- tion: Evidence from Japanese L2 Learners of English. In Proceedings of the 10th Tokyo Conference on Psycholinguistics. Tokyo, Japan FIELDS OF STUDY Major Field: Linguistics vii TABLE OF CONTENTS Page Abstract......................................... ii Dedication........................................ iv Acknowledgments....................................v Vita........................................... vii List of Tables...................................... xi List of Figures...................................... xv Chapters: 1. Introduction....................................1 1.1 Prosody in L1 Spoken Word Recognition.................6 1.2 Prosody in L2 Spoken Word Recognition................. 11 1.3 Overview of Chapters........................... 18 2. Theoretical Background............................. 20 2.1 L2 Speech Model.............................. 20 2.1.1 Perceptual Assimilation Model (PAM; Best, 1995)........ 21 2.1.2 Speech Learning Model (SLM; Flege, 1995)........... 24 2.2 Intonational Structure........................... 28 2.2.1 English Metrical and Intonation Structure............. 29 2.2.2 The Role of Lexical Stress in English Spoken Word Recognition 32 2.2.3 Korean Intonation Structure.................... 42 2.2.4 Korean Speaker’s Use of English Lexical Stress......... 46 2.3 Research Question and Prediction..................... 49 viii 3. Preliminary Study................................. 52 3.1 Methodology................................ 53 3.1.1 Visual World Paradigm...................... 54 3.1.2 Eyetracking Methodology..................... 57 3.1.3 Eye Movements.......................... 58 3.2 Design and Materials............................ 60 3.2.1 Auditory Stimulus Materials.................... 60 3.2.2 Acoustic Phonetic Measurements................. 62 3.2.3 Visual Stimulus Materials..................... 69 3.3 Participants................................. 69 3.4 Procedures................................. 72 3.4.1 Training Session.......................... 72 3.4.2 Eyetracking Word Recognition Experiment............ 74 3.4.3 Listening-with-Orthographic Transcription Task......... 75 3.5 Data Analysis...............................