Evaluation of Cochlear Implant Candidates using a Non-linguistic Spectrotemporal Modulation Detection Test

Adults who score 50% correct or less in open-set sentence recognition test under the best aided listening condition may be considered as candidates for cochlear implant (CI). However, the requirement for ‘the best aided listening condition’ needs significant time and clinical resources to ensure such condition. As speech signals are composed of dynamic spectral and temporal modulations, psychoacoustic sensitivity to the combinations of spectral and temporal modulation cues may be a strong predictor for aided speech recognition. In this study, we tested 27 adults with moderately severe to profound hearing loss to explore the possibility that a non-linguistic unaided spectrotemporal modulation (STM) detection test might be a viable option as a surrogate measure to evaluate CI candidacy. Our results showed that STM detection thresholds were significantly correlated with aided sentence recognition scores for the 27 hearing impaired listeners. The receiver operator characteristic (ROC) curve analysis demonstrated that the CI candidacy evaluation by both unaided STM detection test and the traditional best-aided sentence recognition test was fairly consistent. More specifically, our results demonstrated that the STM detection test using a low spectral and temporal modulation rate might provide an efficient process for CI candidacy evaluation.