An Influence of Directional Microphones on the Speech Intelligibility and Spatial Perception by Cochlear Implant Users
DOI:
https://doi.org/10.1515/aoa-2015-0010Keywords:
Localization, Bilateral cochlear implants, Adults, Microphone, BeamformerAbstract
The objective of the study is to assess the hearing performance of cochlear implant users in three device microphone configurations: omni-directional, directional, and beamformer (BEAMformer two-adaptive noise reduction system), in localization and speech perception tasks in dynamically changing listening environments. Seven cochlear implant users aided with Cochlear CM-24 devices with Freedom speech processor participated in the study. For the localization test in quiet and in background noise, subjects demonstrated significant differences between different microphone settings. Confusion matrices showed that in about 70% cases cochlear implant subjects correctly localized sounds within a horizontal angle of 30–40◦ (±1◦ loudspeaker apart from signal source). However localization in noise was less accurate as shown by a large number of considerable errors in localization in the confusion matrices. Average results indicated no significant difference between three microphone configurations. For speech presented from the front 3 dB SNR improvements in speech intelligibility in three subjects can be observed for beamforming system compared to directional and omni-directional microphone settings. The benefits of using different microphone settings in cochlear implant devices in dynamically changing listening conditions depend on the particular sound environment.References
BOOTHROYD A., HANIN L., HNATH T. (1985), A sentence tests of speech perception:
Reliability, set equivalence, and short-term learning. New York: City University of New York, Speech and Hearing Sciences Research Center.
BROCKMEYER A. M., POTTS L. G. (2011), Evaluation of Different Signal Processing Options in Unilateral and Bilateral Cochlear Freedom Implant Recipients Using R-SpaceTM Background Noise, J Am Acad Audiol, 26, 65–80.
CHUNG K., ZENG F.− G., ACKER K. N. (2006), Effect of directional microphone and adaptive multi-channel noise reduction algorithm on cochlear implant performance, J. Acoust. Soc. Am., 120(4), 2216–2227.
CHUNG K., ZENG F.−G. (2009), Using adaptive directional microphones to enhance cochlearimplant performance, Hear. Res., 25, 27–37.
DUNNC. C., TYLER R. S. WITT S. A., et al. (2004), Frequency and Electrode Contributions to Localization In Bilateral Cochlear Implants. In Miyamoto, R. (Ed.), Cochlear Implants (443–446). Amsterdam: Elsevier.
DUNN C. C., TYLER S. R., OAKLEY S. A., et al. (2008), Comparison of Speech Recognition and Localization Performance In Bilateral and Unilateral Cochlear Implant Users Matched on Duration of Deafness and Age at Implantation, Ear Hear, 29(3), 352–359.
GREENBERG Z. E., ZUREK P. M. (1992), Evaluation of an adaptive beamforming method forhearing aids, J. Acoust. Soc. Am., 91, 1662–1676.
GOLDSWORTHY R. L. (2005), Noise reduction Algorithms and Performance Metrics for Improving Speech Reception in Noise by Cochlear-Implant Users (MIT, Cambridge).
HAWKINS D. B., YACULLO W.S. (1984), Signal-to-noise ratio advantages of binaural hearingaids and directional microphones under different levels of reverberation, J. Speech Disord., 49, 278–286.
HOCHBERG I., BOOTHROYD A., WEISS M., et al. (1992), Effects of noise and noise
suppression on speech perception by cochlear implant users, Ear Hear, 13, 263–271.
HOLDEN L. K., SKINNER M. W., HOLDEN T. A. (1995), Comparison of the normal and noise- suppression settings on the spectra 22 speech processor of the Nucleus 22- channel cochlear implant system, Am J Audiol, 4, 55–58.
HU Y., LOIZOU P. C., LI N., et al. (2007), Use of a sigmoidal-shaped function for noise
attenuation in cochlear implants, J. Acoust. Soc. Am., 122, EL128–EL134.
HU Y., LOIZOU P. C. (2007), A comparative intelligibility study of single-microphone noise reduction algorithms, J. Acoust. Soc. Am., 122(3), 1777–1786.
KOCHKIN S. (2000) MarkeTrak V: Why my hearing aids are in the drawer: The consumer’s perspective. Hearing Review, 53, 34–41.
KOKKINAKIS K., LOIZOU P. C. (2010), Multi-microphone adaptive noise reduction strategies for coordinated stimulation in bilateral cochlear implant devices, J. Acoust. Soc. Am., 127(5), 3136–3144.
KOKKINAKIS K., AZIMI B., HU Y., et al. (2012), Single and Multiple Microphone Noise Reduction strategies in Cochlear Implants, Trends Amplify 16(2), 102-116.
KOMPIS M., DILLIER N. (1994), Noise reduction for hearing aids: Combining directional microphones with an adaptive beamformer, J. Acoust. Soc. Am., 96, 1910–1913.
KOMPIS M., BETTLER M., VISCHWE M., et al. (2004), Bilateral cochlear implantation and directional multi-microphone systems. In Cochlear Implants, R. Miyamoto (Eds). International Congress Series (pp, 447–450). Elsevier: Amsterdam, The Netherlands, 2004.
KOMPIS M., BERTRAM M., FRANCOIS J. et al. (2008), A Two-Microphone Noise Reduction System for Cochlear Implant Users with Nearby Microphones—Part I: Signal Processing Algorithm Design and Development, EURASIP Journal on Advances in Signal Processing, 1–9.
LOIZOU P. C., LOBO A., HU Y. (2005), Subspace algorithms for noise reduction in cochlear implants (L), J. Acoust. Soc. Am., 118(5), 2791–2793.
McCREERY R. W., VENEDIKTOV R. A., COLEMAN J. J. et al. (2012), An Evidence-Based Systematic Review of Directional Microphones and Digital Noise Reduction Hearing Aids in School-Age Children with Hearing Loss, Am J Audiol., (PMID: 22858614).
MÜLLER J., SCHÖNE J., HELMS J. (2002), Speech understanding in quiet and noise in
bilateral users of the MED-EL COMBI 40/40+ cochlear implant system, Ear Hear, 23(3), 198–206.
PLOMP R. (1994), Noise, amplification, and compression: Considerations of 3 main issues in hearing –aid design, Ear Hear, 15, 2–12.
QIN M. K., OXENHAM A. J. (2003), Effects of simulated cochlear implant processing on speech reception in fluctuating maskers, J. Acoust. Soc. Am., 114, 446–454.
SAPAR A. DORMAN M. F. LOISELLE L. H. (2007), Performance of patients using different cochlear systems: effects of input dynamic range, Ear Hear, 28, 260–275.
SCHAFER E. C. THIBODEAU L. M. (2004), Speech recognition abilities of adults using cochlear implants with FM systems, J Am Acad Audiol, 15, 678–691.
SPRIET A., VAN DEUN L., EFTAXIADIS K., et al. (2007), Speech Understanding in
background noise with the two-microphone adaptive beamformer BEAM TM in the Nucleus FreedomTM Cochlear Implant system. Ear Hear, 28(1), 62–72.
STICKNEY G. S., ZENG F.−G., LITOVSKY R., et al. (2004), Cochlear implant speech
recognition with speech masker, J. Acoust. Soc. Am., 116(2), 1081–1091.
SWANSON B., VAN BAELEN E., JANESSENS M., et al. (2007), Cochlear Implant signal Processing ICs. Custom Integrated Circuits Conference, 2007, CICC’07. IEEE, p: 437–442.
TILLMAN T. W., CARHART R. (1966), An expanded test for speech discrimination utilizing CNC monosyllabic words: Northwestern University Auditory Test No. 6 (Tech. Rep. No. SAM TR-66-55). Brooks Air Force Base, TX: USAF School of Aerospace Medicine.
TYLER R. S., KELSAY D. (1990), Advantages and disadvantages reported by some of the better cochlear implant patients, Am J Otolaryngol, 11(4), 282–289.
TYLER R. S., BAKER L. J., ARMSRONG BEDNALL G. (1983), Difficulties experienced by hearing aid candidates and hearing aid users, Br J Audiol, 17(3), 191–201.
TYLER R. S., NOBLE W., DUNN C.C., et al. (2006), Some benefits and limitations of binaural cochlear implants and our ability to measure them. Int J Audiol, 45 (Suppl 1), 113–119.
TYLER R. S., PREECE J., WILSON B., et al. (2002a), Distance, localization and speech perception pilot studies with bilateral cochlear implants. In T. Kubo, Y. Takahashi, and T. Iwaki (Eds.), Cochlear Implants – An Update (517-522). The Hague: Kugler Publications.
TYLER R. S., GANTZ B. J., RUBINSTEIN J. T. et al. (2002b), Three-month results with bilateral cochlear implants. Ear Hear, 23 (Suppl 1), 80S–89S.
TYLER R. S., PARKINSON A. J., WILSON B. S., et al. (2002c), Patients utilizing a hearing aid and a cochlear implant: Speech perception and localization. Ear Hear, 23(2), 98–105.
TYLER R.S. DUNN C.C, WITT S. A. et al. (2007), Speech Perception and Localization with Adults with Bilateral Sequential Cochlear Implants. Ear Hear, 28(2), 86S–90S.
TYLER R. S., WITT S. A., DUNN C. C. et al. (2010), Initial development of a spatially separated speech-in-noise and localization training program. J Am Acad Audiol., 21(6), 390–403.
VAN HOESEL R. J., CLARK G. M. (1995), Evaluation of a portable two-microphone adaptive beamforming speech processor with cochlear implant patients. J. Acoust. Soc. Am., 97(4), 2498–2503.
VAN DEN BOGAERT T., DOLCO S., WOUTERS J., et al. (2009), Speech enhancements with multichannel Winer filter techniques in multimicrophone binaural hearing aids. J. Acoust. Soc. Am., 125, 360–371.
WEISS M. (1993), Effect of noise and noise reduction processing on the operation of the Nucleus-22 cochlear implant processor. JRRD, 30, 117–128.
WOUTERS J., VAN DEN BERGHE J. (2001), Speech recognition in noise for cochlear implantees with a two-microphone monaural adaptive noise reduction system. Ear Hear, 22, 420–430.
WOLFE J., PARKINSON A., SCHAFER E.C., et al. (2012), Benefit of a commercially available cochlear implant processor with dual-microphone beamforming: a multi-center study. Otol Neurotol. 33(4), 553–560.
WOLFE J., SCHAFER E. C. HELDNER B., et al. (2009), Evaluation of speech recognition in noise with cochlear implants and dynamic FM. J Am Acad Audiol, 20, 409–421.
YANG L., FU Q. (2004), Spectral subtraction-based speech enhancement for cochlear implant patients in background noise. J. Acoust. Soc. Am., 117, 1001–1004.
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