Language development of two sets of twins in each of which only 1 twin had hearing impairment

Abstract

　We reviewed the language development by long-term observation of two sets twins in each of which only one twin had hearing impairment. We analyzed the developmental test results (the intelligence test, PVT and reading), the mean length of utterance (MLU), the record of the mother and the video. There were no significant differences in the results of the developmental tests, although there appeared to be a difference in the language concept formation and seeming for there to be a limitation in the volume of information. The results suggest the need for active intervention from the early stage seemed to be necessary in children with mild to moderate hearing loss.