The Enigma of Poor Performance by Adults With Cochlear Implants

Abstract

Objective Considerable unexplained variability and large individual differences exist in speech recognition outcomes for postlingually deaf adults who use cochlear implants (CIs), and a sizeable fraction of CI users can be considered “poor performers.” This paper summarizes our current knowledge of poor CI performance, and provides suggestions to clinicians managing these patients. Method Studies are reviewed pertaining to speech recognition variability in adults with hearing loss. Findings are augmented by recent studies in our laboratories examining outcomes in postlingually deaf adults with CIs. Results In addition to conventional clinical predictors of CI performance (e.g., amount of residual hearing, duration of deafness), factors pertaining to both “bottom-up” auditory sensitivity to the spectro-temporal details of speech, and “top-down” linguistic knowledge and neurocognitive functions contribute to CI outcomes. Conclusions The broad array of factors that contribute to speech recognition performance in adult CI users suggests the potential both for novel diagnostic assessment batteries to explain poor performance, and also new rehabilitation strategies for patients who exhibit poor outcomes. Moreover, this broad array of factors determining outcome performance suggests the need to treat individual CI patients using a personalized rehabilitation approach.

High- and Low-Performing Adult Cochlear Implant Users on High-Variability Sentence Recognition: Differences in Auditory Spectral Resolution and Neurocognitive Functioning

“…Some specific neurocognitive skills, such as working memory capacity, appear to be more strongly related to speech perception and recognition and may be more strongly related than more general cognitive abilities, such as nonverbal intelligence (for a review, see Akeroyd) 1 . Working memory (Lyxell et al; 29 Tao et al) 52 as well as inhibitory control (Moberly et al 31 ), verbal learning and memory (Pisoni et al) 25 , and processing speed (Tinnemore et al) 53 have been linked to individual differences in speech recognition among adult CI users. In addition, although a strong relation has not been established, nonverbal reasoning skills have recently been found to be associated with individual performance among postlingually deafened adult CI users, independently of age (Mattingly et al) 30 .…”

Acoustic Change Responses to Amplitude Modulation in Cochlear Implant Users: Relationships to Speech Perception

“…Nonetheless, the source of the variability in CI performance is still unknown. In general, factors explaining this variation in individual speech perception ability include the bottom-up processing of the auditory periphery to acoustic features (including spectral and temporal information) and topdown cognitive processing at the cortex level (Moberly et al, 2016). However, demographic factors such as age at implantation and duration of deafness merely explain 20% of the variability in CI outcomes (Lazard et al, 2012).…”

Genetic variants in the peripheral auditory system significantly affect adult cochlear implant performance

“…For adults who are postlingually deafened, factors that contribute to CI outcome include the amount of residual hearing, duration of deafness, neurocognitive functioning, device implanted, method of implantation, surgeon experience, postoperative complications and environmental variables such as socioeconomic status (Moberly et al, 2016). However, two recent studies on a cohort of 2,251 patients conducted using two different statistical modeling methods found that only 10.5% and 22% of variance in postoperative speech perception testing could be accounted for by considering up to 9 different clinical factors (Blamey et al, 2013; Lazard et al, 2012).…”