Beijing,Changsha And Guangzhou Dialect Speakers' Production And Perception Of English Lexical Stress

Research into perceiving and producing English lexical stress has become an area of intense interest in second language(L2)acquisition.L2 English learners experience difficulty in producing,and perceiving native-like English lexical stress due to the prosodic transfer effects of their first language(L1).Chinese learners face problems in learning English lexical stress which are assumed to arise from L1 tonal transfer.Chinese regional dialects have effects on English learners in areas such as phonology,syntax,semantics,and stylistics.Scant attention has been paid on the effects dialects have on L2 stress acquisition.English is a stressed-timed language.Stressed syllables are usually produc ed with relatively higher fundamental frequency(F0),greater intensity,longer duration,nonreduced vowels than unstressed syllables.Chinese is a typical tonal language.It is generally agreed that F0 is the main acoustic cue for Chinese tones.Whether there is word-level stress in Chinese languages is currently an unsettled question.All Chinese dialects share this tonal system,some dialects are distinguishable by whether or not they have word-level stress.It is possible that these differences among L1 dialect speakers may affect the speech perception and production and prosodic features in L2 English learners.The present dissertation reports an investigation of L1 regional dialect prosodic transfer effects on English lexical stress production and perception by L2 learners,purposing to assist English language learners to acquire more standard pronunciation and facilitate speech communication.The present study involved the stress acquisition data from 20 native American English(AE)and 60 Chinese di alects-speaking learners of English from three representative,but distinct,Chinese dialects-Beijing(BJ),Changsha(CS),and Guangzhou(GZ).Experiments using real words,nonce words,and manipulated words were conducted to examine the English lexical stress production(Experiment 1 and 2)and perception(Experiment 3 and 4)by L2 learners of the three dialects.In the production experiment,L1 dialect prosodic transfer effects on English lexical stress production were investigated.The experiment measured acoustic characteristics including mean F0,peak F0 location,F0 contour,duration,intensity and vowel quality of real disyllabic words produced by the participants(Experiment 1);and F0,duration,and intensity of nonce words(Experiment 2).These two production experiments showed that Chinese dialect speakers produced significantly fewer nativelike stress patterns,although utilizing all the acoustic cues to distinguish stressed from unstressed syllables.Participants performed better with real words than with nonce words.Experiment 1 showed that 1)American English speakers used a combination of F0,duration and intensity to produce English lexical stress,while Chinese speakers did not use these cues in an exquisite way.Chinese s peakers produced significantly fewer native-like stress patterns probably due to Chinese dialect tonal transfer effects;and,2)Chinese dialect speakers diverged from American speakers reflecting the transfer of their L1 dialect characteristics.All three dialect groups were able to produce native-like intensity ratios,but they showed some differences in F0 and duration cues.BJ and GZ speakers produced native-like F0 ratios but CS speakers did not.BJ,CS,and AE speakers used duration comparably in stress contrasts.GZ speakers produced significantly different duration ratios than AE speakers.There were significant differences in vowel quality across the four groups.Experiment 2 showed that: 1)all three dialect groups exhibited higher F0,shorter duration,lower intensity than AE speakers in English lexical stress production.Acoustic parameter differences between native and non-native speakers was significant;and,2)Significant acoustic differences were found among the three Chinese dialect groups in using F0 and duration cue,but not in intensity.Experiment 1 and 2 results suggest that the native dialect background is a potentially influential factor which may transfer from L1 to L2.L1 prosody and rhythmic typology constrains L2 lexical stress production.In the perception experiment,prosodic transfer effects of L1 dialect on the perception of English lexical stress were investigated.In Experiment 3,F0,duration,intensity and vowel quality were systematically manipulated using nonce disyllabic words.Participants were required to perform a four-words sequence recall task to judge lexical stress positions and the responses were compared.In Experiment 4,F0,duration,and intensity were manipulated at five levels to explore the extent of the use of acoustic cues by different Chinese dialect listeners.Experiment 3 results support the conclusion that the participants performed better in natural sounds than with the manipulated words.Natural words accuracy rates were high and fast.This study focused on performance differences of manipulated words.Results suggest that: 1)BJ,CS and GZ groups tended to rely on F0 cue more than native American English listeners in perceiving English lexical stress,but relied less on duration cue condition;2)All four groups performed similarly when processing nonce words in F0 condition.BJ and CS listeners performed better in duration cue condition and vowel quality condition than GZ listeners.Reaction time results showed that different acoustic cues processing time across language groups varied significantly.Experiment 4 results suggest that 1)the four groups differed in their reliance on F0,duration and intensity cues when perceiving English lexical stress;2)While all three cues showed significant effects on stress perception for AE listeners,only F0 had a decisive influence on stress judgments for BJ and GZ listeners.F0 and duration contributed significantly to CS listeners stress judgment.This finding argues that there was transfer of reliance on F0 to the L2 stress perception.The results of Experiments 3 and 4 suggest that L1 dialect effects are robust in the L2 listeners' perception tasks.The results suggest that production and perception of English lexical stress underlie different restrictions.BJ and CS listeners stress performances but not the GZ listeners,are more similar than those of the AE listeners,both in terms of acoustic cue weighting and cues relative strengths in different stress patterns.In most cases,there was a similar discrepancy between perception and production.Positive parameter settings in L1 facilitate the production and perception of L2 stress were found.Both L1 and L2 participants optimized their perception which coincides with the production that they encountered.This suggests that their perception copes well with certain acoustic aspects of their L1.L1 listeners sought to reach an optimal perception and came to apply available perceptual cues in the most efficient possible fashion.Depending on different L1/ dialects,L2 learners arrived at an optimal perception or manifested sub-optimal optimization strategies specific to L2 acquisition.These results generally conform to the experiment al hypotheses and are explicable in terms of Stress Typology Model(STM),Contrastive Analysis Hypothesis(CAH),Cue-weighting Theory(CWT),Perception Assimilation Model(PAM),and Speech Learning Model(SLM).Moreover,the STM was supported and extended,and t he Dialect Prosodic Transfer(DPT)model was proposed based on the experimental findings.A possible conclusion from these results are that L2 acoustic correlates differ by dialect regions even when L1 learner dialects differ only subtly.Lastly,results provide further evidence that this influence is the res ult of direct L1 dialect transfer.Results reveal that L1 native dialect background should be considered as a potentially influential factor which may transfer in L2 speech encoding and decoding process.It is suggested that the exploration of impact of L1 dialect on L2 stress acquisition is very important for L2 acquisition theories and also for L2 stress teaching.