| Peer-Reviewed

New Technologies of Directional Microphones for Hearing Aids

Received: 25 May 2020     Accepted: 11 June 2020     Published: 23 June 2020
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Abstract

This paper describes new technologies of directional microphones for the practical hearing aids, referring to a front-delay direction microphone (DM), narrow beam DM, and minimum variance distortionless response (MVDR) beamformer. Each of the DM technologies was researched against weaknesses of those existing DMs, such as imperfection in low level noise, short suppression to adjacent interference, and failing to simultaneously perceive multiple target voices. In order to eliminate them, the conventional DM architectures have been innovated: the front-delay DM exchanged the elements’ positions; the narrow beam DM employed binaural DMs to composite a relatively narrow lobe; the MVDR beamformer combined two types of processing in spatial and frequency domains; and the novel technologies are state-of-the-art beamformers for hearing aids. Based on some references related to the DM technologies and operation principles of the latest beamformers, we further researched the DM technologies, first proposed the implementing architectures, derived new gain equations of the relevant polar plots, accomplished the extensive experiments, and evaluated advantages and disadvantages of the DMs by the obtained evidences; then we confirmed that the new technologies could reach their expected goals. Meanwhile, we used the latest simulating software, Simulink of MatLab R2018b and audio edition software, SoundBooth, in our Lab computers.

Published in Journal of Electrical and Electronic Engineering (Volume 8, Issue 3)
DOI 10.11648/j.jeee.20200803.12
Page(s) 81-91
Creative Commons

This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2020. Published by Science Publishing Group

Keywords

Directional Microphone, Beamformer, Minimum Variance Distortionless Response, Hearing Aid

References
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[3] Moeller, K., Jespersen, C., The effect of bandsplit directionality on speech recognition and noise perception. The Hearing Review, 2013, 20 (5), 17-24.
[4] Zhang, X., Spectrum distortion of a directional microphone and its removal for hearing. IJISMS, 2019, 3 (5), 14-22.
[5] Phonak Insight Paper, Binaural directionality. Stafa, Switzerland, 2010, pp. 1-4.
[6] Chalupper, J., Wu, Y. H., Improving effectiveness of directional microphones with Soft Level Directivity. The Hearing Journal, 2011, 64 (7), 44-46.
[7] Latzel, M., Binaural VoiceStream Technology® - Intelligent binaural algorithms to improve speech understanding. Phonak Insight, 2012, Stafa, Switzerland, V1: 1-3. https://www.phonakpro.com/content/dam/phonakpro/gc_hq/en/resources/evidence/white_paper/documents/Insight_Binaural _VoiceStream_Technology_028-0773.pdf.
[8] Kamkar-Parsi, H., Pipl-lng, E. F., Aubreville, M. New binaural strategies for enhanced hearing. The Hearing Review, 2014, 21 (10), 42-45.
[9] Vorobyov, S. A., Principles of minimum variance robust adaptive beamforming design. Signal Processing, 2013, 93 (2013), 3264-3277.
[10] Le Goff, N., Jensen, J., Pedersen, M. S., Callaway, S. L., An introduction to OpenSound NavigatorTM. White Paper, 2016, Oticon, A/S.
[11] Application Note, Directional microphones. 2019, Copyright by Sonion. https://www.sonion.com/hearing/microphones/directional-microphones/.
[12] Voice Samples-LAMP, Free voice for words with life. 2020, Copyright by PRC-Saltllo. https://aacapps.com/lamp/voices.
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[16] Suchum, D. J., Noise reduction via signal processing: (1) Strategies used in other industries. The Hearing Journal, 2003, 56 (5), 27-32.
[17] Kahrs, M., Brandenburg, K., Applications of Digital Signal Processing to Audio and Acoustics. Kluwer Academic Publishers, ©2002, New York, USA.
[18] Weile, J. N., Bach R., The VeloxTJM platform. Tech Paper, 2016, Oticon A/S. https://www.oticon.global/professionals/training-and-fitting/ training/e-learning/velox-platform.
[19] Cracium, A., Gabrea, M., Correlation coefficient-based voice activity detector algorithm. Canadian Conference on ECE, 2004, 3: 1789-1792. Doi: 10.1109/CCECE.2004.1349763.
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Cite This Article
  • APA Style

    Xubao Zhang. (2020). New Technologies of Directional Microphones for Hearing Aids. Journal of Electrical and Electronic Engineering, 8(3), 81-91. https://doi.org/10.11648/j.jeee.20200803.12

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    ACS Style

    Xubao Zhang. New Technologies of Directional Microphones for Hearing Aids. J. Electr. Electron. Eng. 2020, 8(3), 81-91. doi: 10.11648/j.jeee.20200803.12

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    AMA Style

    Xubao Zhang. New Technologies of Directional Microphones for Hearing Aids. J Electr Electron Eng. 2020;8(3):81-91. doi: 10.11648/j.jeee.20200803.12

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  • @article{10.11648/j.jeee.20200803.12,
      author = {Xubao Zhang},
      title = {New Technologies of Directional Microphones for Hearing Aids},
      journal = {Journal of Electrical and Electronic Engineering},
      volume = {8},
      number = {3},
      pages = {81-91},
      doi = {10.11648/j.jeee.20200803.12},
      url = {https://doi.org/10.11648/j.jeee.20200803.12},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.jeee.20200803.12},
      abstract = {This paper describes new technologies of directional microphones for the practical hearing aids, referring to a front-delay direction microphone (DM), narrow beam DM, and minimum variance distortionless response (MVDR) beamformer. Each of the DM technologies was researched against weaknesses of those existing DMs, such as imperfection in low level noise, short suppression to adjacent interference, and failing to simultaneously perceive multiple target voices. In order to eliminate them, the conventional DM architectures have been innovated: the front-delay DM exchanged the elements’ positions; the narrow beam DM employed binaural DMs to composite a relatively narrow lobe; the MVDR beamformer combined two types of processing in spatial and frequency domains; and the novel technologies are state-of-the-art beamformers for hearing aids. Based on some references related to the DM technologies and operation principles of the latest beamformers, we further researched the DM technologies, first proposed the implementing architectures, derived new gain equations of the relevant polar plots, accomplished the extensive experiments, and evaluated advantages and disadvantages of the DMs by the obtained evidences; then we confirmed that the new technologies could reach their expected goals. Meanwhile, we used the latest simulating software, Simulink of MatLab R2018b and audio edition software, SoundBooth, in our Lab computers.},
     year = {2020}
    }
    

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    AU  - Xubao Zhang
    Y1  - 2020/06/23
    PY  - 2020
    N1  - https://doi.org/10.11648/j.jeee.20200803.12
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    T2  - Journal of Electrical and Electronic Engineering
    JF  - Journal of Electrical and Electronic Engineering
    JO  - Journal of Electrical and Electronic Engineering
    SP  - 81
    EP  - 91
    PB  - Science Publishing Group
    SN  - 2329-1605
    UR  - https://doi.org/10.11648/j.jeee.20200803.12
    AB  - This paper describes new technologies of directional microphones for the practical hearing aids, referring to a front-delay direction microphone (DM), narrow beam DM, and minimum variance distortionless response (MVDR) beamformer. Each of the DM technologies was researched against weaknesses of those existing DMs, such as imperfection in low level noise, short suppression to adjacent interference, and failing to simultaneously perceive multiple target voices. In order to eliminate them, the conventional DM architectures have been innovated: the front-delay DM exchanged the elements’ positions; the narrow beam DM employed binaural DMs to composite a relatively narrow lobe; the MVDR beamformer combined two types of processing in spatial and frequency domains; and the novel technologies are state-of-the-art beamformers for hearing aids. Based on some references related to the DM technologies and operation principles of the latest beamformers, we further researched the DM technologies, first proposed the implementing architectures, derived new gain equations of the relevant polar plots, accomplished the extensive experiments, and evaluated advantages and disadvantages of the DMs by the obtained evidences; then we confirmed that the new technologies could reach their expected goals. Meanwhile, we used the latest simulating software, Simulink of MatLab R2018b and audio edition software, SoundBooth, in our Lab computers.
    VL  - 8
    IS  - 3
    ER  - 

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Author Information
  • Research & Development, Sonova Unitron, Kitchener, Canada

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