Outcomes of Children
Progress July 2007
We have enrolled 350 children via the AH service provision network in NSW, VIC and QLD. All children received intervention within the first 3 years of life, with about 54% of children before 6 months of age. The language data from 172 children (112 with hearing aids and 60 with cochlear implants) revealed that:Children who received hearing aids before 6 months of age developed receptive and expressive language like normal-hearing children do, whereas children who received hearing aids after 6 months of age scored on average 1 standard deviation below the normative population.
Age of fitting, rather than degree of hearing loss or prescription used for fitting, is a dominant predictor of language development.
Early intervention leads to better language at 6 months, after controlling for hearing loss
Significant effect of age of fitting: p = 0.003
Effect of prescription: p =0.3
Children who received cochlear implants before 12 months of age developed language like normal-hearing children do, whereas children who received cochlear implants after 12 months of age scored on average 2 standard deviations below the normative population.
Implantation before 12 months leads to better language
The advantage of early intervention/ implantation is maintained one year after children received hearing aids and/or cochlear implants.
These interim findings may change when all data become available. In addition to age of intervention and degree of hearing loss, language development can be affected by other factors (socioeconomic status, cognitive ability, parental involvement and many others). The same would apply to outcomes in other dimensions (speech production, speech perception, psychosocial development, and many others). We do not as yet have sufficient data to consider all factors and outcomes in our analyses. Therefore, the fundamental question about whether newborn hearing screening is effective in improving language and educational outcomes of hearing-impaired children remains unanswered. Nevertheless, we will be able to provide a definitive answer to the question when all data become available.