title: Digital noise reduction: outcomes from laboratory and field studies.
abstract: The purpose of this study was to determine the impact of a digital noise reduction (DNR) scheme implemented in a current commercial hearing aid. In a double-blinded design, three conditions of onset time (4, 8, 16 seconds) were randomly assigned to the 25 subjects, plus one condition wherein the noise-reduction feature was disengaged. Subsequently, a fifth trial/condition, wherein the subject had access to three memories in which the different onsets were programmed, was carried out. For each of the five conditions, the subjects had an at-home trial, prior to obtaining self-report measures. Laboratory measures of speech perception showed no effect of the DNR, with or without the provision of visual cues. Laboratory-based ratings of ease of listening showed DNR-on (all onset times) to be rated significantly better than DNR-off; for ratings of listening comfort, the 4-second onset time was rated significantly lower (poorer) than the 8-second onset or the DNR-off condition; for ratings of sound quality, DNR-on or -off had no differential effect. Self-report measures indicated significantly higher aversiveness in the DNR-off condition compared to the pre-test scores.
authors.affiliation: Department of Speech Pathology & Audiology, University of Iowa, Iowa City, IA 52242, USA. ruth-bentler@uiowa.edu
authors.forename: Ruth
authors.initials: R
authors.lastname: Bentler
authors.forename: Yu-Hsiang
authors.initials: YH
authors.lastname: Wu
authors.forename: Jerrica
authors.initials: J
authors.lastname: Kettel
authors.forename: Richard
authors.initials: R
authors.lastname: Hurtig
mesh_terms: D000328:Adult; D000368:Aged; D004311:Double-Blind Method; D004867:Equipment Design; D005260:Female; D006310:Hearing Aids; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013067:Speech Perception; D013069:Speech Reception Threshold Test