Fundamental frequency of infants' and parents' utterances in longitudinal recordings.
The fundamental frequencies (F0) of daily life utterances of Japanese infants and their parents from the infant's birth until about 5 years of age were longitudinally analyzed. The analysis revealed that an infant's F0 mean decreases as a function of month of age. It also showed that within- and between-utterance variability in infant F0 is different before and after the onset of two-word utterances, probably reflecting the difference between linguistic and nonlinguistic utterances. Parents' F0 mean is high in infant-directed speech (IDS) before the onset of two-word utterances, but it gradually decreases and reaches almost the same value as in adult-directed speech after the onset of two-word utterances. The between-utterance variability of parents' F0 in IDS is large before the onset of two-word utterances and it subsequently becomes smaller. It is suggested that these changes of parents' F0 are closely related to the feasibility of communication between infants and parents.
Amano
Shigeaki
S
NTT Communication Science Laboratories, NTT Corporation, 2-4 Hikari-dai, Seika-cho, Souraku-gun, Kyoto 6190237, Japan.
Nakatani
Tomohiro
T
Kondo
Tadahisa
T
D000328:Adult; D002663:Child Language; D002675:Child, Preschool; D003142:Communication; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008037:Linguistics; D008137:Longitudinal Studies; D008297:Male; D010287:Parent-Child Relations; D013061:Speech Acoustics