LONGITUDINAL OUTCOMES OF CHILDREN WITH HEARING IMPAIRMENT (LOCHI): INTERIM RESEARCH FINDINGS ON LANGUAGE DEVELOPMENT

Mahler N,Ching T, Brower A, Cook C, Cornick S, Crowe K,  Day J, Flynn C, Hou S, Krynda G, Law C,  McGhie K,  Mahler N, Martin V,  Street L,  van Buynder P, Youn S, Zhang V.

National Acoustic Laboratories. Brisbane, Australia.

A prospective study investigating the outcomes of children with hearing impairment (N=470) who first received intervention prior to their third birthday was commenced in 2005 by National Acoustic Laboratories (NAL). The study aims to measure the effect of a range of factors on the speech, language, functional, educational and psycho-social development of this cohort over the initial five years of intervention. Standardised speech and language assessments, custom-designed tests and a range of parent and teacher report forms are administered to participants at set intervals. The current paper reports interim findings of language development as measured globally by the Preschool Language Scale (PLS-4), and more specifically of receptive vocabulary by the Peabody Picture Vocabulary Test (PPVT). The impact of several factors on language development in the presence of a hearing impairment is evaluated with reference to these data, including age of audiological intervention, mode of amplification, degree of hearing impairment, and hearing aid prescription. Although the age of intervention had a significant effect on children’s language scores when measured 12 months after the initial hearing aid fitting, at three years of age, the severity of hearing loss, rather than the age of intervention, had a significant effect. The language scores from standardised tests were significantly correlated with parents’ and teachers’ evaluations of children’s functional performance in everyday life. Furthermore, age of cochlear implantation had a significant effect on children’s language development. Children who received a cochlear implant prior to 12 months of age achieved language scores within the normal range, whereas children who received later implantation performed at or below 1 SD of the normative mean. General developmental trends as indicated by these preliminary data will be discussed briefly.

E-mail: Nicole.Mahler-Thompson@hearing.com.au