Communication outcomes related to early implantation

This study aimed to document the communicative outcomes of early implantation.

It is hypothesized that by implanting children between the ages of 2 and 5 years, it would be possible to capitalize on the critical period of language learning that occurs in the preschool years and thus positively effect communicative outcomes.

Thirty-three children who were between 2 and 5 years at the time of implantation were followed longitudinally. They were administered a battery of speech perception (closed and open set), speech production, and oral language (vocabulary and syntax) tests at five test intervals across a 3-year span.

Open-set speech perception was attained by 24 months with mean scores of 70% correct phonemes by the end of year 3. Speech production improved to mean scores of 90% for suprasegmental features and 88% and 69% for vowels and consonants, respectively, by 3 years postimplant. These children made 33 months' gain in receptive vocabulary and 48 months' gain in expressive vocabulary in 36 months' time. Syntactically, they progressed from simple vocalization to simple sentences with some grammatical elements present. Repeated measures analysis of variance showed no significant differences between the subjects implanted between 2 and 3 years of age and those implanted between 3 and 5 years of age at any period. Within groups, the scores obtained for each test period were significantly different from each other.

Rapid improvement was noted in speech production and language acquisition after improved speech perception for these children implanted before 5 years of age, at levels that exceed those reported in the literature for children implanted at older ages.