First International Conference on Spoken Language Processing (ICSLP 90)
The vocal behaviour of 26 young infants was recorded in order to throw some light on speech acquisition processes. So far, acoustic analyses were carried out for 4 infants aged from 2 to 17 months. Infants were addressed by either their mother, adults unfamiliar to them, or voices presented to them through a loudspeaker. Results were as follows. (1) Even very young infants were able to produce a wide spectrum of speech-like sounds, for example with abrupt F0 changes, or with various voice qualities, characterized by the richness of subharmonic components and of noise components. (2) Mothers tended to use a wider and higher F0 range while speaking to their child than while speaking to adults. (3) Vocal behaviour of infants change according to how and by whom they were spoken to. They produced longer vocalizations in response to their mother's incentive speech, and they did so more often than with other adults.
Bibliographic reference. Shimura, Yoko / Imaizumi, Satoshi / Saito, Kozue / Ichijama, Tamiko / Gauffin, Jan / Halle, Pierre / Yamanouchi, Itsuro (1990): "Infants' vocalization observed in verbal communication: acoustic analysis", In ICSLP-1990, 1329-1332.