Objective: The aim of the study was to assess the speech development of children with at least 2 years' hearing experience with a cochlear implant (CI).
Methods: One hundred and six children were tested, all of whom had used the CI for at least 2 years. Receptive and expressive language development were tested using the scales of early communication skills for hearing-impaired children after Geers and Moog and the Reynell developmental language scales III. In addition, free-field audiometry was performed. Pre-postoperative measurements were compared statistically, and a linear regression analysis was carried out.
Results: Clear improvements in the gain in functional hearing 2 years after receiving the CI as well as clear improvements in both speech perception and speech production were ascertained. All deviations were statistically highly significant (P<0.000). The receptive and expressive speech test results correlate positively to a great extent. The results of logistic regressive analysis indicate that the speech production measured depends decisively on age at implantation, age at time of test, speech production before implantation, and additional handicaps.
Conclusion: Based on the conception of the WHO, a statistically significant improvement of both impairment and disability can be confirmed. In the present study, the regression analysis established the age at implantation as the most important prognostic factor. While the percentage of children with good speech development is larger with early implanted children than with late implanted children, some of the children among the early implanted group show unsatisfactory speech development of unknown origin. Improvements in speech development are likely to be achieved when more children are diagnosed and implanted early. This finding urgently requires the introduction of a general newborn screening program. Thorough anamnesis and assessment during parent counseling of the manifold factors described are a prerequisite for the precise estimation of the difficulties to be met and the expected effectiveness of the implant in each individual case.