Cochlear Implants Improve Verbal Comprehension and Working Memory in Adults: A Cross-sectional Study on the Effect of Aural Rehabilitation with Cochlear Implants on Cognitive Function in Adults

Abstract

Introduction: The association between hearing and cognitive ability has previously been shown in hearing loss and cognitive decline in the elderly, however, few studies have looked at the effect of aural rehabilitation on cognitive improvement. While it has been shown that cochlear implants have significant benefits to speech perception, quality of life, and listening effort, the effect of cochlear implants on cognitive ability, and the associations between cognitive ability and other outcomes of cochlear implants, have yet to be explored. Aims: The primary aim of this research was to assess whether an association exists between hearing improvement due to cochlear implantation and cognitive ability in adults. Additionally, this study aimed to determine whether a relationship exists between cognitive ability and selfperceived hearing, and quality of life. Finally, this study aimed to perform a clinical evaluation of the Self-Administered Gerocognitive Examination cognitive assessment. Methods: Data was collected from 21 participants of which 12 wore cochlear implants for at least six months and 9 were on the waiting list. Cognitive ability was assessed by the sevensubtest short-form of WAIS-IV, and SAGE; speech perception was measured using HINT sentences in quiet and noise. Quality of life was assessed using the NCIQ and self-perceived performance was assessed using the HaCQ. These associations were assessed cross-sectionally and longitudinally, through a case study via pre- and 3-month post- measurements. Results: The CI group performed significantly better on cognitive measures of verbal comprehension and working memory than WL group. Marginal improvements were also observed in global cognitive ability. A significant correlation between verbal comprehension and self-perceived performance, and QoL were found, as was a significant correlation between the SAGE and WAIS-IV. Improvements in all areas were seen in the case study three months postswitch- on compared to pre-implantation. Conclusions: Findings support the idea that cochlear implants reduce cognitive load by improving hearing, allowing cognitive resources to be allocated to areas of cognitive function. This research highlights the importance of aural rehabilitation of a severe-profound hearing loss with cochlear implants, and the need for incorporating cognitive factors into consideration in the audiological setting.