Relative salience of suprasegmental features on judgments of L2 comprehensibility and accentedness

Abstract

Abstract Suprasegmentals have been emphasized in ESL/EFL pedagogy since the advent of communicative language teaching. However, it is still unclear how individual suprasegmental features affect listeners' judgments of non-native speakers' accented speech. The current study began to specify relative weights of individual temporal and prosodic features for listeners' judgments on L2 comprehensibility and accentedness. Using the PRAAT computer program, 5 min of continuous in-class lectures from 11 international teaching assistants (ITAs) were acoustically analyzed for measures of speech rate, pauses, stress, and pitch range. Fifty eight US undergraduate students evaluated the ITAs' oral performance and commented on their ratings. The results revealed that suprasegmental features independently contributed to listeners' perceptual judgments. Accent ratings were best predicted by pitch range and word stress measures whereas comprehensibility scores were mostly associated with speaking rates. ITAs' acoustic profiles as well as listeners' comments on their rating offer practical implications to ITA program developers, ESL teachers, and future research in accented speech.