title: Bilateral versus unilateral cochlear implants in children: speech recognition, sound localization, and parental reports.
abstract: OBJECTIVE
  To compare bilateral and unilateral speech recognition in quiet and in multi-source noise, and horizontal sound localization of low and high frequency sounds in children with bilateral cochlear implants.
  
  
  METHODS
  Bilateral performance was compared to performance of the implanted side with the best monaural speech recognition in quiet result. Parental reports were collected in a questionnaire. Results from the CI children were compared to binaural and monaural performance of normal-hearing peers.
  
  
  METHODS
  Sixty-four children aged 5.1-11.9 years who were daily users of bilateral cochlear implants. Thirty normal-hearing children aged 4.8-9.0 years were recruited as controls.
  
  
  CONCLUSIONS
  Group data showed a statistically significant bilateral speech recognition and sound localization benefit, both behaviorally and in parental reports. The bilateral speech recognition benefit was smaller in quiet than in noise. The majority of subjects localized high and low frequency sounds significantly better than chance using bilateral implants, while localization accuracy was close to chance using unilateral implants. Binaural normal-hearing performance was better than bilateral performance in implanted children across tests, while bilaterally implanted children showed better localization than normal-hearing children under acute monaural conditions.
authors.affiliation: Department of ENT, Section of Cochlear Implants, Karolinska University Hospital, Stockholm, Sweden. filip.asp@ki.se
authors.forename: Filip
authors.initials: F
authors.lastname: Asp
authors.forename: Elina
authors.initials: E
authors.lastname: Mäki-Torkko
authors.forename: Eva
authors.initials: E
authors.lastname: Karltorp
authors.forename: Henrik
authors.initials: H
authors.lastname: Harder
authors.forename: Leif
authors.initials: L
authors.lastname: Hergils
authors.forename: Gunnar
authors.initials: G
authors.lastname: Eskilsson
authors.forename: Stefan
authors.initials: S
authors.lastname: Stenfelt
mesh_terms: D000161:Acoustic Stimulation; D001309:Auditory Threshold; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003054:Cochlear Implants; D003638:Deafness / Q000601:surgery; D006801:Humans; D016014:Linear Models; D009622:Noise; D010290:Parents; D013017:Sound Localization; D013067:Speech Perception; D011795:Surveys and Questionnaires