Preoperative Reading Efficiency as a Predictor of Adult Cochlear Implant Outcomes

Hypotheses 1) Scores of reading efficiency (the Test of Word Reading Efficiency, second edition) obtained in adults before cochlear implant surgery will be predictive of speech recognition outcomes 6 months after surgery; and 2) Cochlear implantation will lead to improvements in language processing as measured through reading efficiency from preimplantation to postimplantation. Background Adult cochlear implant (CI) users display remarkable variability in speech recognition outcomes. “Top-down” processing—the use of cognitive resources to make sense of degraded speech—contributes to speech recognition abilities in CI users. One area that has received little attention is the efficiency of lexical and phonological processing. In this study, a visual measure of word and nonword reading efficiency—relying on lexical and phonological processing, respectively—was investigated for its ability to predict CI speech recognition outcomes, as well as to identify any improvements after implantation. Methods Twenty-four postlingually deaf adult CI candidates were tested on the Test of Word Reading Efficiency, Second Edition preoperatively and again 6 months post-CI. Six-month post-CI speech recognition measures were also assessed across a battery of word and sentence recognition. Results Preoperative nonword reading scores were moderately predictive of sentence recognition outcomes, but real word reading scores were not; word recognition scores were not predicted by either. No 6-month post-CI improvement was demonstrated in either word or nonword reading efficiency. Conclusion Phonological processing as measured by the Test of Word Reading Efficiency, Second Edition nonword reading predicts to a moderate degree 6-month sentence recognition outcomes in adult CI users. Reading efficiency did not improve after implantation, although this could be because of the relatively short duration of CI use.