Developmental trends of perceiving happy voice in preverbal infants

Abstract

Perception of emotional prosody is essential for children to identify emotions of communication partners from utterances. Newborns prefer listening to happy talks but children start to weight emotional prosody over lexical meanings to judge emotions in speech around middle childhood. Happy voice is expressed with higher fundamental frequency (F0) and F0 variations in syllables manifest lexical tones in Mandarin. Would lexical tones affect happy prosody perception development in preverbal infants? The goal of this study was to explore whether the ability of perceiving happy prosody varies with lexical tones. Mandarin-learning children master the production of Tone 2 earlier than Tone 3, and development trend of lexical tone production might reflect perceptual trends of lexical tones. Thirty-nine Mandarin-learning 7- and 11-month-old infants were tested with two prosody (happy vs. neutral prosody) contrasts in a speech discrimination task. For each contrast, speech stimuli were monosyllabic words /ji/, varied with emotional prosody. Tonal information (Tone 2 or Tone 3) varied between contrasts and remained the same within a contrast. Results showed that older infants were more accurate than younger infants to distinguish happy prosody and the pitch contours of lexical tones did not greatly shift the developmental trend.