The effects of acoustically enhanced speech on lexical tone perception in Mandarin as second language learners

Abstract

The tonal language learners who speak non-tone language have difficulty discriminating lexical tones of a tone language. This study aimed to examine the effects of acoustically enhanced speech on perceptual sensitivities and organizations of lexical tones in Mandarin as second language learners. Three groups of participants were recruited, native Mandarin speakers (n = 26), native English speakers (n = 28), and native Thai speakers (n = 26). Both groups of Mandarin learners have learnt Mandarin as second language (L2) for several years. Mandarin lexical tone discrimination and identification tasks with two sets of tone stimuli, with and without pitch contour exaggeration, were used in this study. The results showed that Mandarin L2 learners performed less well on the tone discrimination and identification tasks, relative to native Mandarin speakers. In addition, Mandarin L2 learners perceptually weight less to pitch direction than pitch height in their perceptual organization for tones, showing different perceptual weights from native Mandarin speakers. In the context of listening to acoustically enhanced stimuli, the group difference on tonal sensitivity and cue-weighting patterns of perceptual organization were greatly reduced. Results imply that the signal enhancement facilitates Mandarin L2 learners to process lexical tones.