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DOI: 10.3766/jaaa.18030
AutoAdaptive: A Noise Level–Sensitive Beamformer for MED EL Cochlear Implant Patients
Publikationsverlauf
Publikationsdatum:
25. Mai 2020 (online)
![](https://www.thieme-connect.de/media/10.1055-s-00046128/201908/lookinside/thumbnails/10-3766-jaaa-18030_00731-1.jpg)
Abstract
Background:
When cochlear implant (CI) listeners use a directional microphone or beamformer system to improve speech understanding in noise, the gain in understanding for speech presented from the front of the listener coexists with a decrease in speech understanding from the back. One way to maximize the usefulness of these systems is to keep a microphone in the omnidirectional mode in low noise and then switch to directional mode in high noise.
Purpose:
The purpose of this experiment was to assess the levels of speech understanding in noise allowed by a new signal processing algorithm for MED EL CIs, AutoAdaptive, which operates in the manner described previously.
Research Design:
Seven listeners fit with bilateral CIs were tested in a simulation of a crowded restaurant with speech presented from the front and from the back at three noise levels, 45, 55, and 65 dB SPL.
Data Collection and Analysis:
The listeners were seated in the middle of an array of eight loudspeakers. Sentences from the AzBio sentence lists were presented from loudspeakers at 0 or 180° azimuth. Restaurant noise at 45, 55, and 65 dB SPL was presented from all eight loudspeakers. The speech understanding scores (words correct) were subjected to a two-factor (speaker location and noise level), repeated measures, analysis of variance with posttests.
Results:
The analysis of variance showed a main effect for level and location and a significant interaction. Posttests showed that speech understanding scores from front and back loudspeakers did not differ significantly at the 45- and 55-dB noise levels but did differ significantly at the 65-dB noise level—with increased scores for signals from the front and decreased scores for signals from the back.
Conclusions:
The AutoAdaptive feature provides omnidirectional benefit at low noise levels, i.e., similar levels of speech understanding for talkers in front of, and in back of, a listener and beamformer benefit at higher noise levels, i.e., increased speech understanding for signals from in front. The automatic switching feature will be of value to the many patients who prefer not to manually switch programs on their CIs.
This work was conducted at Arizona State University and was supported by a grant from MED EL Corporation.
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REFERENCES
- Archer-Boyd A, Homan J, Brimijoin W. 2018; The minimum monitoring signal-to-noise ratio for off-axis signals and its impoication for directional hearing aids. Hear Res 357: 64-72
- Buechner A, Dyballa K-H, Hehrmann P, Fredelake S, Lenarz T. 2014; Advanced beamformers for cochlear implant users: acute measurement of speech perception in challenging listening conditions. PLoS One 9 (04) e95542
- Compton-Conley CL, Neuman AC, Killion MC, Levitt H. 2004; Performance of directional microphones for hearing aids: real-world versus simulation. J Am Acad Audiol 15 (06) 440-55
- Cord M, Surr R, Walden B, Dyrlund O. 2004; Relationship between laboratory measures of directional advantage and everyday success with directional microphone hearing aids. J Am Acad Audiol 15 (05) 353-364
- Dorman M, Natale S, Loiselle L. 2018; Speech understanding and sound source localization by cochlear implant listeners using a pinna-effect imitating microphone and an adaptive beamformer. J Am Acad Audiol 29 (03) 197-205
- Dorman M, Natale S, Spahr A, Castioni E. 2017; Speech understanding in noise by cochlear implant patients using a monaural adaptive beamformer. J Speech, Lang Hear Res 60 (08) 2360-2363
- Kokkinakis K, Azimi B, Hu Y, Friedland D. 2012; Single and multiple microphone noise reduction strategies in cochlear implants. Trends Amplif 16 (02) 102-116
- Kuk F, Keenan D, Lau S, Ludvigsen C. 2005; Performance of a fully adaptive directional microphone to signals presented from various azimuths. J Am Acad Audiol 16 (06) 335-347
- Revit LJ, Killion MC, Compton-Conley CL. 2007; Developing and testing a laboratory sound system that yields accurate real-world results. Hear Rev 14 (11) 54-62
- Spahr A, Dorman M, Litvak L, van Wie S, Gifford R, Loiselle L, Oakes T, Cook S. 2012; Development and validation of the AzBio sentence lists. Ear Hear 33 (01) 112-117
- Surr R, Walden B, Cord M, Olson L. 2002; Influence of environmental factors on hearing aid microphone preference. J Am Acad Audiol 13 (06) 308-322
- Spriet A, van Deun L, Eftaxiadis K, Laneau J, Moonen M, van Dijk B, van Wieringen A, Wouters J. 2007; Speech understanding in background noise with the two-microphone adaptive beamformer BEAM in the Nucleus Freedom Cochlear Implant System. Ear Hear 28 (01) 62-72
- Wolfe J, Parkinson A, Schafer A, Gilden J, Rehwinkel K, Mansanares J, Coughlan E, Wright J, Torres J, Gannaway S. 2012; Benefit of a commercially available cochlear implant processor with dual-microphone beamforming: a multi-center study. Oto Neurotol 33 (04) 553-560