The effects of hearing loss and age of intervention on some language metrics in young hearing-impaired children.

This study examined the oral language production abilities of a group of young children with bilateral sensorineural hearing impairments (greater than 25 dB HL). The effects of age of intervention-as indexed by age of detection, referral, first appointment and hearing-aid fitting-and of the severity of their hearing impairments on spoken language and communication were the foci of the study. Children were aged between 27 and 80 months with hearing threshold levels ranging from 32 to 98 dB in the better ear. All were audio- and video-taped in their own homes, in an unstructured play setting with the mother. Measures of expressive language ability were extracted including mean length of utterance, vocabulary size, words per min., total utterance attempts per min., proportion of non-verbal utterances and the proportion of questions asked by the child. No significant correlations were found between the children's hearing impairments and their scores on the language measures once age at interview had been statistically controlled. However, significant correlations were found between the language measures and the ages at which the children received intervention for their hearing impairments, in particular for vocabulary and those language measures denoting the rate and quality of the child's interaction during the episode recorded. This finding is consistent with some of the arguments to be found in the small body of data addressing the question of early intervention.