effect of early intervention on language development in hearing-impaired children

introduction: hearing loss from birth up to the age of 3 years has a negative effect on speech/language development and results in sensory, cognitive, emotional, and academic defects in adulthood by causing delayed development of communicative-linguistic abilities. the present study was performed in order to assess the effect of early intervention on language development in persian children aged 6-7 years with severe sensorineural hearing loss.   materials and methods: thirty boys and girls aged 6-7 years participated in this study, all of them had severe congenital sensorineural hearing loss in both ears. all children were using bilateral behind-the-ear hearing aid, and had similar economic/socio-cultural backgrounds. subjects were categorized into two groups based on the age of identification/intervention of hearing loss (3-6 and 12-15 months of age). the persian told-p3 test was used to evaluate language development in all subjects. data collection was accomplished by observation, completion of questionnaires, and speech recording.   results: there was a significant difference in language development in 11 sub-tests and five lingual gains on the persian told-p3 test between early (3-6 months of age) and late identified/intervened (12-15 months of age) hearing-impaired children (p<0.05). early identified/intervened hearing-impaired children had a notable preference in all assessed sub-tests and lingual gains.   conclusion:  early identification/intervention of hearing loss before the age of 6 months has a significant positive effect on a child’s language development in terms of picture/relational/oral vocabulary, grammatical comprehension, sentence combining, grammatical completion, phonologic analysis, word differentiation, word production, semantics, and syntax. moreover, early identification/ intervention of hearing loss develops the hearing-impaired child’s lingual gains in visual vocabulary, grammatical completion, word differentiation, phonologic analysis, and word production.