title: Envelope versus fine structure speech coding strategy: a crossover study.
abstract: OBJECTIVE
  The transmission of fine structure information to cochlear implant users is an expanding area of research. Previous studies comparing the fine structure processing (FSP) speech coding strategy to the envelope-based continuous interleaved sampling (CIS) strategy indicated improved speech perception when using the fine structure strategy. Those investigations were performed with an extended frequency spectrum in the low frequencies together with the fine structure strategy. The current study addresses the question whether these improvements are due to the presentation of fine structure per se or rather the extended frequency spectrum. Hence, this cross over study compares the two strategies using an identical frequency spectrum.
  
  
  METHODS
  Randomized crossover study.
  
  
  METHODS
  31 patients were randomly assigned to two groups.
  
  
  METHODS
  One group was fitted with a CIS map for 4 weeks, tested and subsequently fitted with a FSP map for 4 weeks. The other group followed the same pattern in reverse.
  
  
  METHODS
  Test material consisted of sentence tests in noise, monosyllables in quiet and melody recognition.
  
  
  RESULTS
  No statistical significance was noted between the different speech coding strategies at an identical frequency spectrum.
  
  
  CONCLUSIONS
  This study shows that there is no difference in speech perception with FSP compared to CIS at an extended frequency spectrum. Therefore, the extended frequency spectrum in the low frequencies might explain a benefit of FSP observed in previous studies.
authors.affiliation: Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria.
authors.forename: Dominik
authors.initials: D
authors.lastname: Riss
authors.forename: Jafar-Sasan
authors.initials: JS
authors.lastname: Hamzavi
authors.forename: Andreas
authors.initials: A
authors.lastname: Selberherr
authors.forename: Alexandra
authors.initials: A
authors.lastname: Kaider
authors.forename: Michaela
authors.initials: M
authors.lastname: Blineder
authors.forename: Veronika
authors.initials: V
authors.lastname: Starlinger
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Gstoettner
authors.forename: Christoph
authors.initials: C
authors.lastname: Arnoldner
mesh_terms: D000328:Adult; D000368:Aged; D019929:Cochlear Implantation; D003054:Cochlear Implants; D018592:Cross-Over Studies; D005260:Female; D034381:Hearing Loss / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D013063:Speech Discrimination Tests; D013067:Speech Perception / Q000502:physiology*