title: Consequences of Stimulus Type on Higher-Order Processing in Single-Sided Deaf Cochlear Implant Users.
abstract: Single-sided deaf subjects with a cochlear implant (CI) provide the unique opportunity to compare central auditory processing of the electrical input (CI ear) and the acoustic input (normal-hearing, NH, ear) within the same individual. In these individuals, sensory processing differs between their two ears, while cognitive abilities are the same irrespectively of the sensory input. To better understand perceptual-cognitive factors modulating speech intelligibility with a CI, this electroencephalography study examined the central-auditory processing of words, the cognitive abilities, and the speech intelligibility in 10 postlingually single-sided deaf CI users. We found lower hit rates and prolonged response times for word classification during an oddball task for the CI ear when compared with the NH ear. Also, event-related potentials reflecting sensory (N1) and higher-order processing (N2/N4) were prolonged for word classification (targets versus nontargets) with the CI ear compared with the NH ear. Our results suggest that speech processing via the CI ear and the NH ear differs both at sensory (N1) and cognitive (N2/N4) processing stages, thereby affecting the behavioral performance for speech discrimination. These results provide objective evidence for cognition to be a key factor for speech perception under adverse listening conditions, such as the degraded speech signal provided from the CI.
authors.affiliation: Cluster of Excellence ''Hearing4all'', Hannover Medical School, Hannover, Germany.
authors.forename: Mareike
authors.initials: M
authors.lastname: Finke
authors.forename: Pascale
authors.initials: P
authors.lastname: Sandmann
authors.forename: Hanna
authors.initials: H
authors.lastname: Bönitz
authors.forename: Andrej
authors.initials: A
authors.lastname: Kral
authors.forename: Andreas
authors.initials: A
authors.lastname: Büchner
mesh_terms: D000328:Adult; D000368:Aged; D001307:Auditory Perception; D019929:Cochlear Implantation / Q000379:methods; D003054:Cochlear Implants; D003071:Cognition; D003638:Deafness / Q000503:physiopathology / Q000534:rehabilitation*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory; D005260:Female; D046088:Hearing Loss, Unilateral / Q000503:physiopathology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013065:Speech Intelligibility; D013067:Speech Perception