Development of speech-like vocalizations in a child with congenital absence of cochleas: The case of total deafness

Abstract

ABSTRACTIn order to assess the effect of total deafness on vocalization development, tape recorded utterances of a 3-year-old child who was born without cochleas were examined. In the beginning of the study, the subject's speech consisted almost exclusively of small numbers of sounds characteristic of early infancy. Across the study, the subject participated in extensive vocal stimulation activities. He also initially received intermittent exposure to tactile speech information via a 16-channel vocoder and, subsequently, a 2-channel tactile aid. Following introduction of the 2-channel aid, the subject made rapid improvement in the quality of his vocalizations, which consisted increasingly of speech-like utterances, including well-formed or canonical syllables. These results suggest that, although hearing impairment slows the onset of canonical babbling, even total deafness does not preclude its eventual appearance.