Fundamental frequency characteristics of infant non-distress vocalization during the first twenty-four weeks

Abstract

ABSTRACTFundamental frequency (F0) characteristics of non-distress vocalizations produced by four infants during the first twenty-four weeks of life were examined. This study constitutes the beginning of a longitudinal investigation of phonological development displayed by these children from birth to two years. Vocalization samples were obtained from home and laboratory recordings. Period-by-period F0melody plots and descriptive statistics for each utterance were derived from computer analysis. Mean F0centred around 335 Hz, with little variation evidenced when data were pooled. Duration, within-utterance range and variability did show developmental change. Individual F0fluctuations deviating from the mean were felt to be associated with the infant's state, activity levels, and changing vocal repertoire. Sources of variation among studies of infant F0characteristics appear to be related to differences in sampling and measurement techniques.