Third International Conference on Spoken Language Processing (ICSLP 94)
This paper examined two hypotheses; (1) infants produce voices necessary for emotional communication; and (2) Infants interpret emotions contained in their own vocalizations. Voice samples produced by six infants at 6, 9, 12 and 17 months of age were perceptually evaluated by 79 adults (aged 20-22) and 31 children (aged 2-6) using rating scales representing emotions. The following results were obtained. 1) Even six month old infants who have not yet developed a language could produce various voices necessary for emotional communication through nonlinguistic aspects of voice. 2) Both the adult and child listeners perceived rich contents of emotions from the voice samples recorded even at 6 month of age. 3) More factors were needed to account for the rating scores given by the children than by the adults via factor analyses. 4) Children seem to be more sensitive in perception of emotions from infants' vocalization than the adults. These results support the hypothesis that "infants begin to communicate through nonlinguistic aspects of voice at very early stage of their life."
Bibliographic reference. Shimura, Yoko / Imaizumi, Satoshi (1994): "Infant's expression and perception of emotion through vocalizations", In ICSLP-1994, 1703-1706.