A Survey Of The Acquisition Of English Phrasal Stress In Connected Speech By Chinese EFL Learners: An Acoustic Perspective

The importance of teaching and learning English phonetics and phonology is unneglectable. However, there is a gap that needs to be filled between English spoken by Natives and by Chinese EFL learners. It was partly due to the rhythmic difference between two language systems that people from stress-timed language found it difficult to comprehend English made by people from syllable-timed language(Anderson-Hsieh & Venkatagiri,1994). Roach ( 2000: 91 ) further pointed out that incorrect stress placement is the major cause of intelligibility problems for foreign learners, and is therefore a subject that needs to be treated very seriously. For the above reasons, the acquisition of English phrasal stress by Chinese EFL learners is set as the focus of the present study.There is a lack of empirical study in the acquisition of English stress by Chinese EFL learners in the previous studies both at home and abroad. The present study tries to fill this gap based on the theoretical framework by the SPE's linear phonology (Chomsky& Halle, 1968 ) and the Metrical Stress theory ( Hayes, 1995) . A comparison study was conducted between 33 Chinese EFL疤?ners and 11 natives of RP in their productions of 10 English noun phrases embedded in a short passage entitiled—"Cinderrella" ( See Appendix 1). After the reading and recording of the passage is finished, 10 English noun phrases are extracted from the passage for the annotation and acoustic analysis. With the application of the computer software Cool Editor, Praat and SPSS, the recording, acoustic analysis and correlation analysis are conducted. The focus of the survey is divided into three parts, that is, the overall acquisition rate of English phrasal stress by Chinese EFL learners, the linear and non-linear features of phrasal stress assignment by Chinese EFL learners, and the overall acoustic features in the production of 10 test noun phrases by Chinese EFL learners.The study intends to answer the following research questions:(1) What is the overall acquisition rate of 10 English phrasal stress by CEFLLs?(2) What are the acoustic features of 10 English phrasal stress by CEFLLs?(3) What are the major problems revealed in the CEFLLs' production of 10 English phrasal stress ? And why?The perception analysis by the raters includes:The rating of acceptability and being natural by raters on the production of 33 Chinese EFL learners on the basis of the theoretical standard and the production by 11 natives of RP;The linear analysis of the production of 10 English noun phrases by Chinese EFL learners as either left-edge prominence(compounds and narrow focus NPs) or right-edge prominence( broad focus NPs);The non-linear analysis of the production of 10 English noun phrases by Chinese EFL learners in metrical trees and grids for the judgment of whether a hierarchy is achieved or not;The acoustic analysis of the production of 10 English noun phrases includes:Pitch values, pitch contour and pitch range of vowels in the production of 10 Eng疤? noun phrases;Durations of 27 constituents (or words ) in the production of 10 English noun phrases (including primary stressed constituents, secondary stressed constituents and unstressed constituents);Intensity vales of 27 constituents (or words ) in the production of 10 English noun phrases.The findings of the present study are listed in the following:1. the overall acquisition rate of English phrasal stress by Chinese EFL learners(1) The overall acquisition rate of English phrasal stress by Chinese EFL learners is unsatisfactorily low. The mean acquisition rate of 10 English noun phrasal stress is only 23%.(2) In the analysis of three contrastive categories—compounds, narrow focus NPs and broad focus NPs, the mean acquisition rate is low with 19%, among which the acquisition of the broad focus NPs is the highest with 30%, the acquisition rate of compounds is the lowest—only 3%, the acquisition of narrow focus NPs is medium with 23%.2. The findings of perceptions by the raters(1) In linear analysis of the production by Chinese EFL learners, there is a widespread confusion of left-edge prominence ( for compounds and narrow focus NPs) and right-edge prominence( for broad focus NPs) and the vowels in unstressed syllables uncompressed or not reduced effectively.(2) In non-linear analysis, the hierarchy of phrasal stress is unachieved characterized by more stress than necessary, double stress, and some weak forms unrealized.3. The findings of the overall acoustic features in the production of 10 English phrasal stress by Chinese EFL learners(1) In the analysis of pitch, pitch contour and pitch range, the majority of Chinese EFL learners' production is featured by an overall higher pitch than where it is necessary, an over-enlarged pitch range in deep contrast to the natives of RPs resul疤? in an unnecessary exaggeration, and by a misuse of pitch contour ( CEFLLs prefer to use high-fall tone while RPSs prefer to use low-fall-rise or mid-fall-rise tone ) to convey an unnecessary double or equal stress in their articulation.(2) In the analysis of duration for the 27 constituents of 10 English noun phrases by Chinese EFL learners, negative transfer from mother tongue (L1) is found. The duration differences between stressed and unstressed syllables are not salient. Due to the insensitivity of Chinese EFL learners to the duration, which is a contrastive feature in English stress, and the negative transfer from their syllable-stressed mother tongue, the majority of Chinese EFL learners have not acquired the duration as an effective device to distinguish stressed and unstressed syllables.(3) In the analysis of intensity, the overall intensity of constituents is significantly larger than that of natives of RPs. This may partly accounts for the reason why intensity serves as a less supportive cue of stress than pitch, pitch contour and duration.The present study found the acquisition of English phrasal stress by 33 CEFLLs is hardly satisfactory based on the perception from the raters , acoustic analysis and a comparison with 11 English natives of RP. The unacceptable stress assignment by CEFLLs can be traced to both the negative transfer from their mother tongue and developmental errors as well. Meanwhile, suggestions are also provided for teachers to enhance their knowledge on contrastive study of phonetics and phonology between Chinese and English and for students to notice the prosodic differences between English and Chinese first, and then practice ear-trainings and rehearsals before the fossilization is overcome. Besides, computers can also be used to provide learners with visualization of not only their phrasal stress and prosodic patterns and specific contrastive feedback but also authentic and extensive speech and in turn to hone learners' perceptual abilities.