Long-term Change in the Speech Perception Ability in Pediatric Cochlear Implants and the Effect of the Age at Implantation.

OBJECTIVE

We analyzed the long-term changes in speech perception ability of pediatric cochlear implants (CIs) to evaluate the effect of the age at the time of surgery.

STUDY

DESIGN

Retrospective.

SETTING

Tertiary care academic center.

PATIENTS: One hundred fourteen prelingually deaf children with CI use duration >10 years.

MAIN OUTCOME MEASURES: Categories of auditory performance (CAP) scores and monosyllabic word recognition scores using the Asan-Samsung Korean word list (ASK-WRS) and a conventional word list (KS-WRS) were the main outcomes. Outcomes were compared according to the age at surgery (group I, 1-2 yr; II, 2.1-3 yr; III, 3.1-7 yr; IV, 7.1-13 yr).

RESULTS

CAP scores reached plateaus at 2.6 to 3.3 years post-CI; groups I to III showed better scores than group IV. The maximum CAP score was obtained in all children of groups I to III and in 65% of group IV. ASK-WRSs reached plateaus at 3.2 to 4.8 years post-CI. Younger patients at CI operation showed better ASK-WRSs (97, 93, 90, and 54% in groups I-IV, respectively), but the differences were not significant (I versus II and II versus III). Ceiling effect (perfect score) was observed in early groups (67, 44, 30, and 0% in groups I-IV). KS-WRSs, which is a challenging test, reached plateaus at 7.2 to 8.4 years postsurgery with no ceiling effect. Early implantees showed significantly better scores (88, 82, 73, and 46% in groups I-IV).

CONCLUSIONS

Speech perception ability after CI showed audiological age-specific improvement evaluated by various test methods. The most challenging test demonstrated long-term performance differences by the age at CI operation.