Cochlear implantation between 5 and 20 months of age: the onset of babbling and the audiologic outcome.
OBJECTIVE: The objective of this study was to investigate the onset of prelexical babbling and the audiologic outcome of 10 deaf children who received a cochlear implant (CI) before the age of 20 months. STUDY DESIGN: A prospective longitudinal observation and analysis. PATIENTS: Ten congenitally deaf infants implanted at an age between 6 and 18 months. INTERVENTION: All children received a Nucleus-24 multichannel cochlear implant. MAIN OUTCOME MEASURES: 1) The onset of babbling defined as a) the first appearance of multiple articulatory movements and b) a canonical babbling ratio of.2 or higher; 2) the babbling spurt defined as a sudden increase of babbled utterances; 3) the audiologic outcome defined by the CAP score (Categories of Auditory Performance) and the results of the A[S]E (Auditory Speech Sound Evaluation). RESULTS: All children started babbling after a short interval of 1 to 4 months after activation of the device so that the onset of babbling in the youngest subjects occurred at a chronologic age comparable to that of normally hearing infants. The outcomes of the different babbling measures correlated significantly with the age of implantation: the earlier the implantation, the closer the results approached the outcomes of normally hearing infants. The children implanted in their first year of life showed a normal CAP development as early as 3 months after implantation. All CI children were able to discriminate phoneme pairs of the A[S]E immediately after the fitting of the device. CONCLUSIONS: The earlier the implantation took place, the smaller the delay was in comparison with normally hearing children with regard to the onset of prelexical babbling and with regard to auditory performance as measured by CAP.