Longitudinal observations of individual infant's vocalizations.
Twice a week observation of five infants' vocalizations during the first 30 weeks of life showed that hearing impaired infants displayed different language patterns than normally hearing infants. Developmental differences in vocal activity were observed by six weeks of age, suggesting that hearing impaired infants may differ from unimpaired infants earlier than has been believed.
D002663:Child Language; D003448:Crying; D003638:Deafness / Q000523:psychology; D005260:Female; D006311:Hearing Disorders / Q000523:psychology; D006801:Humans; D007223:Infant; D007804:Language Development; D008137:Longitudinal Studies; D008297:Male; D013060:Speech