Second language speech: Production and perception of voicing contrasts in word-final obstruents by Malay speakers of English

Zaharia Pilus

Ph.D. Thesis, 2002

Abstract

This study tests the predictions of the Interlanguage Structural Conformity Hypothesis (ISCH), the Speech Learning Model (SLM), and the Perceptual Assimilation Model (PAM) for the relative difficulty of acquiring voicing contrasts in word-final obstruent pairs /t/-/d/, /s/-/z/, and /f/-/v/ by Malay speakers of English. The study also examines claims in SLM and PAM that perception informs production in L2 acquisition, and that success in L2 speech learning varies with L2 experience. Twenty-one Malay speakers and ten native speakers of American English participated in production and perception experiments. The Malays had significantly lower accuracy scores than the Americans in all experiments. Also, the Malays' scores indicated a hierarchy of relative difficulty across the pairs and the hierarchy varied partially by task. In general, stops were better distinguished for voicing than fricatives, and subjects were less successful in distinguishing /s/ from /z/. An acoustic analysis of production tokens revealed that the Malays were less effective in signaling voicing for /s/ and /z/ than for the other two pairs. The Malays consistently employed glottal pulsing as a significant correlate of voicing. Although ISCH could account for more of the results than SLM and PAM, indicating that phonological markedness has more influence than L2 sound categorizations, ISCH was still unable to predict the entire relative difficulty among the obstruent pairs and within each voicing pair. The subjects' accuracy scores indicated a tendency for perception ability to be better than production ability, as predicted by SLM and PAM. However, because the analyses were limited to accuracy scores, the findings are not entirely robust. Because the Malay subjects were homogenous, differences based on L2 experience could not be evaluated, but accent score and the Malay regional dialects were influential factors in the Malays' performance. This study concludes that the entire distribution of the L1 and L2 sounds systems needs to be considered in order to better predict L2 acquisition difficulty, that factors other than just accuracy rate must be considered to identify skills that lead to L2 success, and that for Malay speakers, the L1 dialect should be considered for influencing L2 performance.