title: Noise reduction technologies implemented in head-worn preprocessors for improving cochlear implant performance in reverberant noise fields.
abstract: The purpose of this study was to investigate whether a multichannel adaptive directional microphone and a modulation-based noise reduction algorithm could enhance cochlear implant performance in reverberant noise fields. A hearing aid was modified to output electrical signals (ePreprocessor) and a cochlear implant speech processor was modified to receive electrical signals (eProcessor). The ePreprocessor was programmed to flat frequency response and linear amplification. Cochlear implant listeners wore the ePreprocessor-eProcessor system in three reverberant noise fields: 1) one noise source with variable locations; 2) three noise sources with variable locations; and 3) eight evenly spaced noise sources from 0° to 360°. Listeners' speech recognition scores were tested when the ePreprocessor was programmed to omnidirectional microphone (OMNI), omnidirectional microphone plus noise reduction algorithm (OMNI + NR), and adaptive directional microphone plus noise reduction algorithm (ADM + NR). They were also tested with their own cochlear implant speech processor (CI_OMNI) in the three noise fields. Additionally, listeners rated overall sound quality preferences on recordings made in the noise fields. Results indicated that ADM+NR produced the highest speech recognition scores and the most preferable rating in all noise fields. Factors requiring attention in the hearing aid-cochlear implant integration process are discussed.
authors: Department of Allied Health and Communication Disorders, Northern Illinois University, 323 Wirtz Hall, DeKalb, IL 60115, USA. kchung@niu.edu
authors: King
authors: K
authors: Chung
authors: Lance
authors: L
authors: Nelson
authors: Melissa
authors: M
authors: Teske
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D000465:Algorithms; D003054:Cochlear Implants / Q000706:statistics & numerical data*; D005260:Female; D006310:Hearing Aids; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise; D012815:Signal Processing, Computer-Assisted; D013067:Speech Perception; D055815:Young Adult