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J Am Acad Audiol 2001; 12(04): 202-214
DOI: 10.1055/s-0042-1745598
Original Article

Efficacy of Directional Microphone Hearing Aids: A Meta-Analytic Perspective

Amyn M. Amlani
Department of Audiology and Speech Sciences, Michigan State University, East Lansing, Michigan
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Abstract

The literature suggests that directional microphone hearing aids (DMHAs) are a viable means for improving the signal-to-noise ratio (SNR) for hearing-impaired listeners. The amount of directional advantage they provide, however, remains relatively unclear because of variability observed among individual studies. The present investigation was undertaken in an attempt to establish the degree of advantage provided by DMHAs. Data were synthesized from 72 and 74 experiments, respectively, on omnidirectional hearing aids and DMHAs representing both favorable and unfavorable outcomes. Using a meta-analytic approach, 138 weighted averages were derived for a variety of comparable independent and dependent variables. Comparisons were made for hearing-impaired and normal-hearing listeners. Findings are discussed with regard to their clinical and research implications.

Abbreviations: BTE - behind the ear, Cl95 = 95 percent confidence interval, DA = directional advantage, DMHA = directional microphone hearing aid, DSP = digital signal processing, HI = hearing impaired, ITE = in the ear, NH = normal hearing, ODHA = omnidirectional microphone hearing aid, RT = reverberation time, SNR = signal-to-noise ratio.

Keywords

Analog signal processing - confidence interval - digital signal processing - directional microphone - meta-analysis - omnidirectional microphone - reverberation - signal-to-noise ratio


Publication History

Article published online:
01 March 2022

© 2001. American Academy of Audiology. This article is published by Thieme.

Thieme Medical Publishers, Inc.
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