SPEECH-PERCEPTION BY PRELINGUALLY DEAF-CHILDREN USING COCHLEAR IMPLANTS

In this investigation we measured the performance of 50 prelingually d eaf children on several speech perception tests, Children were from 2 to 15 years of age, and some children were tested with as much as 5 ye ars of cochlear implant use. Speech perception tests included the reco gnition of stress pattern, consonants, vowels, words, and sentences. T he audiovisual perception of consonants was also measured. Average res ults indicated that gains were being made in the perception of stress and words in a closed-set context within 1 year from implantation. The perception of words in an open-set context demonstrated much slower i ncreases over time. Large individual differences were observed. Some p reliminary data suggest that children who receive implants before the age of 4 years obtain higher scores, on average, than children who rec eive implants after the age of 5 years. Some children become part-time users or nonusers of their cochlear implants. The average results fro m 18 congenitally deaf children were significantly higher than the ave rage results from 12 children with prelingually acquired deafness afte r 3 years of implant use. Information on vowel and consonant features shows increases in performance after 2 years of cochlear implant use, with the exception of the place feature. For this feature, no changes were observed. Vision-alone testing indicated that lipreading performa nce increased over time. An audiovisual enhancement provided by the co chlear implant was observed for all features.