Effects of Bimodal and Bilateral Cochlear Implant Use on a Nonauditory Working Memory Task: Reading Span Tests Over 2 Years Following Cochlear Implantation

Am J Audiol. 2019 Dec 16;28(4):947-963. doi: 10.1044/2019_AJA-19-0030. Epub 2019 Dec 11.


Purpose A growing body of evidence indicates that treatment of hearing loss by provision of hearing aids leads to improvements in auditory and visual working memory. The purpose of this study was to assess whether similar working memory benefits are observed following provision of cochlear implants (CIs). Method Fifteen adults with postlingually acquired severe bilateral sensorineural hearing loss completed the prospective longitudinal study. Participants were candidates for bilateral cochlear implantation with some aidable hearing in each ear. Implantation surgeries were carried out sequentially, approximately 1 year apart. Working memory was measured with the visual Reading Span Test (Daneman & Carpenter, 1980) at 5 time points: pre-operatively following a 6-month bilateral hearing aid trial, after 6 and 12 months of bimodal (CI plus contralateral hearing aid) listening experience following the 1st CI surgery and activation, and again after 6 and 12 months of bilateral CI listening experience following the 2nd CI surgery and activation. Results Compared to the preoperative baseline, CI listening experience yielded significant improvements in participants' ability to recall test words in the correct serial order after 12 months in the bimodal condition. Individual performance outcomes were variable, but almost all participants showed increases in task performance over the course of the study. Conclusions These results suggest that, similar to appropriate interventions with hearing aids, treatment of hearing loss with CIs can yield working memory benefits. A likely mechanism is the freeing of cognitive resources previously devoted to effortful listening.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cochlear Implants* / psychology
  • Cognitive Dysfunction / etiology
  • Cognitive Dysfunction / prevention & control
  • Female
  • Hearing Loss, Sensorineural / psychology
  • Hearing Loss, Sensorineural / therapy
  • Humans
  • Longitudinal Studies
  • Male
  • Memory, Short-Term*
  • Middle Aged
  • Neuropsychological Tests
  • Prospective Studies
  • Reading*