Newborn Infant Cry and Nonhuman Primate Vocalization

Abstract

Cries were recorded from 20 normal newborn infants from birth to the fourth day of life. Sound spectrograms showed that these cries were similar to the vocalizations of nonhuman primates insofar as the infants seemed to produce sounds by means of a uniform cross-section, schwalike, vocal tract configuration. Under certain conditions the laryngeal excitation was breathy and formant frequencies corresponding to an open boundary condition at the glottis were generated. The infants did not produce the range of sounds typical of adult human speech. This inability appears to reflect, in part, limitations imposed by the neonatal vocal apparatus, which, like the nonhuman primate vocal tract, appears to be inherently incapable of producing the full range of human speech. The initial restrictions on the sound-making repertoire of human infants are also evident in previous perceptually based transcriptions of the utterances of infants as well as in spectrographic and cineradiographic studies.