Speech perception skills and speech production intelligibility in French children with prelingual deafness and cochlear implants

Objective: To examine speech perception and production intelligibility in French children with prelingual deafness who received multichannel cochlear implants. Design: Within-subject, repeated-measures design for assessing speech perception and a cross-sectional design for assessing overall speech intelligibility. Setting: A pediatric cochlear implant center. Subjects: Sixty-four French children with prelingual deafness who received multichannel cochlear implants (mean age at time of implantation, 3 years 11 months) underwent assessment for speech perception. A subset of 16 children who received implants by 3 years of age underwent assessment for speech intelligibility. Main Outcome Measures: Speech perception skills were assessed using phoneme detection, closed-set word and sentence recognition, and modified open-set (MOS) recognition. Speech intelligibility was assessed by asking 50 listeners to identify recorded speech samples from the subjects. Dependent variables for the studies consisted of percent of correct items. Results: After implantation, all children were able to detect phonemes by 3 months. Closed-set word and sentence identification reached 100% accuracy by 48 months (7 children with 4 years of implantation experience). Some children (8 of 48) demonstrated some MOS recognition after 1 year. Modified open-set recognition averaged 67.9% by 42 months (12 children available) and 80% by 48 months (7 children available). Overall speech intelligibility was 4.2% after 1 year, 30.7% after 2 years, 55.2% after 3 years, and 74.2% after 4 years. Within-subject comparisons of MOS recognition and overall speech intelligibility scores revealed an insignificant trend for high perceptual performance to be associated with higher speech intelligibility scores (P=.17). There also was a tendency for higher performance to be associated with longer implantation experience. Conclusions: Speech perception scores appear to increase with increased experience using a cochlear implant. Overall speech intelligibility appears to steadily improve with increased experience and appears to be poorly related to perceptual performance on MOS recognition tasks.