Speech perception and speech intelligibility in children after cochlear implantation

This study aimed to evaluate the long-term speech perception and speech intelligibility of congenitally and prelingually deaf children after cochlear implantation. It was a longitudinal study following 63 congenitally or prelingually deaf children up to 5 years after implantation. They each received a nucleus multichannel cochlear implant before they were 10 years old.

Perception is evaluated using the Test for the Evaluation of Voice Perception and Production (TEPP) and concerns closed- and open-set word and sentence perception without lip-reading. The intelligibility is classified according to the Speech Intelligibility Rating (SIR). The evaluations have been made every 3 months for 1 year, then at 18 months, 2 years, 3 years and 5 years after the cochlear implantation.

After 5 years of implantation, the median percentage of closed-words speech perception (CSW) is 95.5%-93.67% for closed-sentence speech perception (CSS) and 76.3% for open-sentence speech perception (OSS); the median Speech Intelligibility Rating is 3.83.

Congenitally and prelingually deaf children who receive cochlear implant before the age of 10 years develop speech perception and speech intelligibility abilities. The closed-set perception progresses quickly and seems to reaching a plateau at 5 years post implantation. The improvement of open-sentence perception is not significant until the first year post implantation. The speech intelligibility improves regularly the five first year post implantation.