Optimal language outcomes for children who are deaf or hard of hearing: Measuring predictor variables

Yoshinaga-Itano, C.

Predicting language outcomes of children identified early through the age of 7 years is dependent upon some critical variables: meeting 1-2-3 (screen by 1, identify by 2 and enroll into early intervention services by 3 months), degree of hearing loss, non-verbal cognitive, amount of parent talk (spoken, signed, combined). Over 7 years, these variables predicted over 65% of the variance in the expressive vocabulary outcomes at 84 months of age. Other variables such as communication approach, gender, race/ethnicity and even maternal level of education, when other variables are considered, are subsumed under other variables and by themselves have not predicted outcome.
Access to language, however, as measured through amount of parent talk (number of parental words (spoken, signed) in a 25 minute video-taped interaction between parent and child), plays a major role. Parent talk and maternal level of education have significant overlapping variance because of the inter-relationships between the two variables. However, when 1-2-3 is introduced as a variable, at least within the Colorado early intervention program, maternal level of education disappeared in our analyses.
Access to spoken language is dependent upon: 1) early diagnosis of the deafness or hearing loss, 2) early access and fitting of amplification, 3) appropriateness of the amplification fit - does the child hear the phonemes of their native language, 4) does the child wear the amplification regularly, and 5) does the child have access to a quantity and quality of spoken language.
Access to visual language is dependent upon: 1) early diagnosis of the deafness or hearing loss, 2) access to quality and quality of visual language input, typically determined by the predominantly hearing parents? access to quality visual language instruction, the child being exposed to high quality and quantity of visual language input, typically determined by access to native/fluent Deaf and hard of hearing adult communicators.
Research focus currently is based upon determining spoken language access immediately after hearing aid fitting through speech discrimination measured at the cortical level through mismatched responses, behavioral discrimination testing at 7 to 12 months of age, and vocabulary development after 12 months of age. Other avenues of research are related to the fidelity of the early intervention services.