title: Investigation of a matrix sentence test in noise: reproducibility and discrimination function in cochlear implant patients.
abstract: OBJECTIVE
  The aim of this study was to describe common properties (reproducibility, discrimination function, and its steepness) of matrix tests used for cochlear implant (CI) users and to obtain data for the German-language version matrix test, the Oldenburg sentence test (OLSA), presented in noise.
  
  
  METHODS
  The speech reception thresholds (SRT) in noise were measured by means of an adaptive test procedure, and by measurement at various signal-to-noise ratios to determine the course of the entire discrimination function per subject.
  
  
  METHODS
  The measurements were performed on 38 CI users fitted with a Cochlear(™) Freedom(®) or a Cochlear(™) Nucleus(®) 5 CI system.
  
  
  RESULTS
  The test-retest reproducibility showed a significant dependence on the SRT in noise. For the better performers, the test-retest difference was found to be smaller, while for the poorer performers the difference increased. For the better performers, the slope of the discrimination function at SRT (s50) was comparable to that for individuals with normal hearing, while for the poorer performers the s50 tended to be significantly reduced.
  
  
  CONCLUSIONS
  As the CI users differed significantly in their SRT and their s50, a unified discrimination function for CI users must not be used. Further tailoring of the procedure may be required, especially for poorer CI performers.
authors.affiliation: Department of ORL, Christian-Albrechts-Universität of Kiel , Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Hey
authors.forename: Thomas
authors.initials: T
authors.lastname: Hocke
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hedderich
authors.forename: Joachim
authors.initials: J
authors.lastname: Müller-Deile
mesh_terms: D000368:Aged; D003054:Cochlear Implants; D005260:Female; D005858:Germany; D006801:Humans; D007802:Language; D008297:Male; D008875:Middle Aged; D009622:Noise; D010361:Patients; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D013063:Speech Discrimination Tests / Q000379:methods*; D013065:Speech Intelligibility; D013067:Speech Perception; D013069:Speech Reception Threshold Test / Q000379:methods*
keywords: OLSA; Oldenburg sentence test; Speech intelligibility test; cochlear implant; intelligibility in noise; matrix sentence test; speech reception threshold; test–retest reproducibility