Relationships between speech production and speech perception skills in young cochlear-implant users

The purpose of this investigation was to examine the relationships between young cochlear-implant users' abilities to produce the speech features of nasality, voicing, duration, frication, and place of articulation and their abilities to utilize the features in three different perceptual conditions: audition-only, vision-only, and audition-plus-vision. Subjects were 23 prelingually deafened children who had at least 2 years of experience with a Cochlear Corporation Nucleus cochlear implant, and an average of 34 months. They completed both the production and perception version of the Children's Audio--visual Feature Test, which is comprised of ten consonant--vowel syllables. An information transmission analysis performed on the confusion matrices revealed that children produced the place of articulation fairly accurately and voicing, duration, and frication less accurately. Acoustic analysis indicated that voiced sounds were not distinguished from unvoiced sounds on the basis of voice onset time or syllabic duration. Subjects who were more likely to produce the place feature correctly were likely to have worn their cochlear implants for a greater length of time. Pearson correlations revealed that subjects who were most likely to hear the place of articulation, nasality, and voicing features in an audition-only condition were also most likely to speak these features correctly. Comparisons of test results collected longitudinally also revealed improvements in production of the features, probably as a result of cochlear-implant experience and/or maturation.