title: Sequential bilateral cochlear implantation: speech perception and localization pre- and post-second cochlear implantation.
abstract: OBJECTIVE
  In this study, the authors sought to compare speech perception and localization in subjects who wear 1 cochlear implant (unilateral CI) or 1 cochlear implant and hearing aid (CI+HA) and then receive a second cochlear implant (bilateral CI), and to evaluate the importance of the duration between implant surgeries and duration of deafness.
  
  
  METHODS
  Nine subjects were tested on speech perception in quiet, and 13 subjects were tested on speech perception and localization in noise using an array of 8 loudspeakers. All subjects were tested with unilateral CI prior to bilateral implantation and then again with bilateral CI after at least 3 months of bilateral experience.
  
  
  RESULTS
  No significant difference was found between bilateral CI and unilateral CI on averaged speech perception in quiet performance. A significant benefit was found for bilateral CI on averaged speech perception in noise and on localization. Nonsignificant correlations were found for duration between surgeries, duration of deafness, and duration of bilateral use.
  
  
  CONCLUSIONS
  Improvements for speech perception and localization played in background noise were indicated for most subjects after they received their 2nd implant. The correlations should be reassessed with a larger number of subjects to appropriately evaluate the effects of duration between surgeries, duration of deafness, and duration of bilateral use.
authors: University of Iowa, Iowa City, IA, USA. camille-dunn@uiowa.edu
authors: Camille C
authors: CC
authors: Dunn
authors: Richard S
authors: RS
authors: Tyler
authors: Shelley
authors: S
authors: Witt
authors: Haihong
authors: H
authors: Ji
authors: Bruce J
authors: BJ
authors: Gantz
mesh_terms: D000328:Adult; D000368:Aged; D019929:Cochlear Implantation / Q000379:methods*; D003054:Cochlear Implants; D003638:Deafness / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013017:Sound Localization; D013067:Speech Perception; D013997:Time Factors; D016896:Treatment Outcome