title: Comparison of Bilateral and Unilateral Cochlear Implantation in Adults: A Randomized Clinical Trial.
abstract: OBJECTIVE
  The cost of bilateral cochlear implantation (BCI) is usually not reimbursed by insurance companies because of a lack of well-designed studies reporting the benefits of a second cochlear implant.
  
  
  OBJECTIVE
  To determine the benefits of simultaneous BCI compared with unilateral cochlear implantation (UCI) in adults with postlingual deafness.
  
  
  METHODS
  A multicenter randomized clinical trial was performed. The study took place in 5 Dutch tertiary referral centers: the University Medical Centers of Utrecht, Maastricht, Groningen, Leiden, and Nijmegen. Forty patients eligible for cochlear implantation met the study criteria and were included from January 12, 2010, through November 2, 2012. The main inclusion criteria were postlingual onset of hearing loss, age of 18 to 70 years, duration of hearing loss of less than 20 years, and a marginal hearing aid benefit. Two participants withdrew from the study before implantation. Nineteen participants were randomized to undergo UCI and 19 to undergo BCI.
  
  
  METHODS
  The BCI group received 2 cochlear implants during 1 surgery. The UCI group received 1 cochlear implant.
  
  
  METHODS
  The primary outcome was the Utrecht Sentence Test with Adaptive Randomized Roving levels (speech in noise, both presented from straight ahead). Secondary outcomes were consonant-vowel-consonant words in silence, speech-intelligibility test with spatially separated sources (speech in noise from different directions), sound localization, and quality of hearing questionnaires. Before any data were collected, the hypothesis was that the BCI group would perform better on the objective and subjective tests that concerned speech intelligibility in noise and spatial hearing.
  
  
  RESULTS
  Thirty-eight patients were included in the study. Fifteen patients in the BCI group used hearing aids before implantation compared with 19 in the UCI group. Otherwise, there were no significant differences between the groups' baseline characteristics. At 1-year follow-up, there were no significant differences between groups on the Utrecht Sentence Test with Adaptive Randomized Roving levels (9.1 dB, UCI group; 8.2 dB, BCI group; P = .39) or the consonant-vowel-consonant test (median percentage correct score 85.0% in the UCI group and 86.8% in the BCI group; P = .21). The BCI group performed significantly better than the UCI group when noise came from different directions (median speech reception threshold in noise, 14.4 dB, BCI group; 5.6 dB, BCI group; P <.001). The BCI group was better able to localize sounds (median correct score of 50.0% at 60°, UCI group; 96.7%, BCI group; P <.001). These results were consistent with the patients' self-reported hearing capabilities.
  
  
  CONCLUSIONS
  This randomized clinical trial demonstrates a significant benefit of simultaneous BCI above UCI in daily listening situations for adults with postlingual deafness.
  
  
  BACKGROUND
  trialregister.nl Identifier: NTR1722.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University Medical Center Utrecht, Utrecht, the Netherlands2Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Yvette E
authors.initials: YE
authors.lastname: Smulders
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University Medical Center Utrecht, Utrecht, the Netherlands2Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Alice
authors.initials: A
authors.lastname: van Zon
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University Medical Center Utrecht, Utrecht, the Netherlands2Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Inge
authors.initials: I
authors.lastname: Stegeman
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Albert B
authors.initials: AB
authors.lastname: Rinia
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University Medical Center Utrecht, Utrecht, the Netherlands2Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Gijsbert A
authors.initials: GA
authors.lastname: Van Zanten
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Maastricht University Medical Center, Maastricht, the Netherlands.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Stokroos
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Maastricht University Medical Center, Maastricht, the Netherlands.
authors.forename: Nadia
authors.initials: N
authors.lastname: Hendrice
authors.affiliation: Department of Otorhinolaryngology-University Medical Center Groningen, Groningen, the Netherlands5Graduate School of Medical Sciences, Research School of Behavioral and Cognitive Neurosciences, University Medical Center Groningen, Groningen, the Netherlan.
authors.forename: Rolien H
authors.initials: RH
authors.lastname: Free
authors.affiliation: Department of Otorhinolaryngology-University Medical Center Groningen, Groningen, the Netherlands5Graduate School of Medical Sciences, Research School of Behavioral and Cognitive Neurosciences, University Medical Center Groningen, Groningen, the Netherlan.
authors.forename: Bert
authors.initials: B
authors.lastname: Maat
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Leiden University Medical Center, Leiden, the Netherlands7Leiden Institute for Brain and Cognition, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Johan H M
authors.initials: JH
authors.lastname: Frijns
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Leiden University Medical Center, Leiden, the Netherlands7Leiden Institute for Brain and Cognition, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Briaire
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Radboud University Medical Center, Nijmegen, the Netherlands9Donders Institute for Brain, Cognition, and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands.
authors.forename: Emmanuel A M
authors.initials: EA
authors.lastname: Mylanus
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Radboud University Medical Center, Nijmegen, the Netherlands9Donders Institute for Brain, Cognition, and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands.
authors.forename: Wendy J
authors.initials: WJ
authors.lastname: Huinck
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University Medical Center Utrecht, Utrecht, the Netherlands2Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Adriana L
authors.initials: AL
authors.lastname: Smit
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University Medical Center Utrecht, Utrecht, the Netherlands2Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Vedat
authors.initials: V
authors.lastname: Topsakal
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University Medical Center Utrecht, Utrecht, the Netherlands2Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Rinze A
authors.initials: RA
authors.lastname: Tange
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University Medical Center Utrecht, Utrecht, the Netherlands2Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Wilko
authors.initials: W
authors.lastname: Grolman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001307:Auditory Perception / Q000502:physiology*; D019929:Cochlear Implantation / Q000379:methods*; D003638:Deafness / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006309:Hearing / Q000502:physiology*; D034381:Hearing Loss / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D006320:Hearing Tests; D006801:Humans; D008297:Male; D008875:Middle Aged; D057566:Self Report; D013067:Speech Perception; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D055815:Young Adult