The weighting of vowel quality in native and non-native listeners' perception of English lexical stress

Although vowel quality is an important cue to the perception of English lexical stress, few studies have examined the role this cue plays for non-native speakers. Previous research found that Mandarin speakers had problems using vowel reduction as a cue in English lexical stress production. Assuming native-like perception is a prerequisite to native-like production for non-native speech, this study compared the weight Mandarin learners and native speakers of English gave to vowel quality as a cue to English lexical stress in comparison to that given to f0, duration and intensity under natural and flat pitch contour conditions. Listeners judged lexical stress placement in synthesized tokens of the word desert, in which the first syllable de- was varied systematically in vowel quality and each of the other cues depending on the pair of cues in focus. Results showed that both English and Mandarin listeners consistently weighted vowel quality more than other cues. Vowel quality and duration were treated as a combinational cue by both language groups. However, Mandarin and English listeners showed different patterns for the processing of vowel quality and other prosodic cues, and Mandarin listeners' processing of vowel quality and pitch cues was influenced by the pitch contour conditions. These findings can be explained in terms of language-specific or cue-specific influence, and provide new insight into the relationship between production and perception in second language speech learning. (C) 2009 Elsevier Ltd. All rights reserved.