title: More challenging speech-perception tasks demonstrate binaural benefit in bilateral cochlear implant users.
abstract: OBJECTIVE
  Preliminary studies show that bilateral cochlear implantation improves speech-recognition ability in many subjects; however, the magnitude of this improvement has been variable. The objective of our research was to explore means to better differentiate the binaural benefit that many patients who receive bilateral cochlear implants (CIs) describe.
  
  
  OBJECTIVE
  Binaural improvements in speech-perception performance will be consistently evident across patients when they are tested in more challenging listening situations.
  
  
  METHODS
  This was a prospective clinical study. Speech-perception performance was compared between the unilateral and bilateral cochlear implant conditions. Because the purpose was to investigate testing parameters that would demonstrate binaural benefit, word- and sentence-recognition tests were administered under several stimulation conditions: with and without noise and at three presentation levels. In addition, all subjects completed the Abbreviated Profile of Hearing Aid Benefit as a measure of subjective benefit. Subjects were adult cochlear implant recipients. Three device manufacturers were represented (Advanced Bionics Corporation, Cochlear Americas, and the Med-El Corporation); three patients received simultaneous implantation, and the other four patients received sequential CIs. The setting was a comprehensive cochlear implant program/tertiary referral center. The main outcomes measures were speech-recognition scores in percent correct, mean score difference for unilateral versus bilateral conditions, and subjective benefit scores.
  
  
  RESULTS
  The most significant improvements in binaural cochlear implant use were found when subjects were tested with sentence material presented at 60 dB SPL with a +8 dB signal-to-noise ratio. Six of seven subjects showed significant binaural improvement, with a mean improvement score of 12.43% (SD = 5.32). All subjects preferred the binaural listening condition. Measured improvements in quality of life were seen.
  
  
  CONCLUSIONS
  Preliminary study findings suggest that significant cochlear implant binaural benefit in speech perception may be observed when testing in more difficult listening situations (i.e., lower presentation levels and in noise). According to the outcome of our study, testing the binaural benefit of CIs requires consideration of suitable test materials and stimulation parameters.
authors.affiliation: Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee, WI 53226, USA. wackym@mcw.edu
authors.forename: P Ashley
authors.initials: PA
authors.lastname: Wackym
authors.forename: Christina L
authors.initials: CL
authors.lastname: Runge-Samuelson
authors.forename: Jill B
authors.initials: JB
authors.lastname: Firszt
authors.forename: Farah Mohd
authors.initials: FM
authors.lastname: Alkaf
authors.forename: Linda S
authors.initials: LS
authors.lastname: Burg
mesh_terms: D000328:Adult; D003054:Cochlear Implants; D005260:Female; D006312:Hearing Loss, Bilateral / Q000175:diagnosis / Q000534:rehabilitation*; D046088:Hearing Loss, Unilateral / Q000175:diagnosis / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D011474:Prosthesis Design; D011788:Quality of Life; D013063:Speech Discrimination Tests; D013067:Speech Perception