title: Information theoretic evaluation of a noiseband-based cochlear implant simulator.
abstract: Noise-band vocoders are often used to simulate the signal processing algorithms used in cochlear implants (CIs), producing acoustic stimuli that may be presented to normal hearing (NH) subjects. Such evaluations may obviate the heterogeneity of CI user populations, achieving greater experimental control than when testing on CI subjects. However, it remains an open question whether advancements in algorithms developed on NH subjects using a simulator will necessarily improve performance in CI users. This study assessed the similarity in vowel identification of CI subjects and NH subjects using an 8-channel noise-band vocoder simulator configured to match input and output frequencies or to mimic output after a basalward shift of input frequencies. Under each stimulus condition, NH subjects performed the task both with and without feedback/training. Similarity of NH subjects to CI users was evaluated using correct identification rates and information theoretic approaches. Feedback/training produced higher rates of correct identification, as expected, but also resulted in error patterns that were closer to those of the CI users. Further evaluation remains necessary to determine how patterns of confusion at the token level are affected by the various parameters in CI simulators, providing insight into how a true CI simulation may be developed to facilitate more rapid prototyping and testing of novel CI signal processing and electrical stimulation strategies.
authors.affiliation: School of Electrical & Computer Engineering, Purdue University, West Lafayette, IN, USA.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Aguiar
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA.
authors.forename: N Ellen
authors.initials: NE
authors.lastname: Taylor
authors.affiliation: School of Electrical & Computer Engineering, Purdue University, West Lafayette, IN, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Electrical & Computer Engineering, Purdue University, West Lafayette, IN, USA.
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Gazanfari
authors.affiliation: School of Electrical & Computer Engineering, Purdue University, West Lafayette, IN, USA; Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA. Electronic address: tmt@purdue.edu.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Talavage
authors.affiliation: School of Electrical & Computer Engineering, Purdue University, West Lafayette, IN, USA.
authors.forename: J Brandon
authors.initials: JB
authors.lastname: Laflen
authors.affiliation: DeVault Otologic Research Laboratory, Department of Otolaryngology/Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Heidi
authors.initials: H
authors.lastname: Neuberger
authors.affiliation: DeVault Otologic Research Laboratory, Department of Otolaryngology/Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Otolaryngology-Head & Neck Surgery, New York University School of Medicine, New York, NY, USA.
authors.forename: Mario A
authors.initials: MA
authors.lastname: Svirsky
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D016022:Case-Control Studies; D019929:Cochlear Implantation / Q000295:instrumentation*; D003054:Cochlear Implants; D003198:Computer Simulation; D004558:Electric Stimulation; D030141:Feedback, Psychological; D005260:Female; D006801:Humans; D007257:Information Theory; D008297:Male; D008875:Middle Aged; D019986:Persons with Hearing Disabilities / Q000523:psychology / Q000534:rehabilitation*; D011474:Prosthesis Design; D011571:Psychoacoustics; D021641:Recognition, Psychology; D012815:Signal Processing, Computer-Assisted; D013061:Speech Acoustics; D013067:Speech Perception; D014833:Voice Quality; D055815:Young Adult
keywords: Cochlear implant; Noiseband vocoder; Psychophysics; Simulation; Vowel perception