J Am Acad Audiol 2020; 31(07): 506-512
DOI: 10.3766/jaaa.19025
Research Article

Effect of Microphone Location and Beamforming Technology on Speech Recognition in Pediatric Cochlear Implant Recipients

Jourdan T. Holder
1  Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN
,
Adrian L. Taylor
1  Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN
,
Linsey W. Sunderhaus
1  Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN
,
René H. Gifford
1  Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN
› Author Affiliations
Funding Funding was provided by NIDCD R01 DC009404 (investigator effort) and an unrestricted research grant from Advanced Bionics (participant renumeration).

Abstract

Background Despite improvements in cochlear implant (CI) technology, pediatric CI recipients continue to have more difficulty understanding speech than their typically hearing peers in background noise. A variety of strategies have been evaluated to help mitigate this disparity, such as signal processing, remote microphone technology, and microphone placement. Previous studies regarding microphone placement used speech processors that are now dated, and most studies investigating the improvement of speech recognition in background noise included adult listeners only.

Purpose The purpose of the present study was to investigate the effects of microphone location and beamforming technology on speech understanding for pediatric CI recipients in noise.

Research Design A prospective, repeated-measures, within-participant design was used to compare performance across listening conditions.

Study Sample A total of nine children (aged 6.6 to 15.3 years) with at least one Advanced Bionics CI were recruited for this study.

Data Collection and Analysis The Basic English Lexicon Sentences and AzBio Sentences were presented at 0o azimuth at 65-dB SPL in +5 signal-to-noise ratio noise presented from seven speakers using the R-SPACE system (Advanced Bionics, Valencia, CA). Performance was compared across three omnidirectional microphone configurations (processor microphone, T-Mic 2, and processor + T-Mic 2) and two directional microphone configurations (UltraZoom and auto UltraZoom). The two youngest participants were not tested in the directional microphone configurations.

Results No significant differences were found between the various omnidirectional microphone configurations. UltraZoom provided significant benefit over all omnidirectional microphone configurations (T-Mic 2, p = 0.004, processor microphone, p < 0.001, and processor microphone + T-Mic 2, p = 0.018) but was not significantly different from auto UltraZoom (p = 0.176).

Conclusions All omnidirectional microphone configurations yielded similar performance, suggesting that a child's listening performance in noise will not be compromised by choosing the microphone configuration best suited for the child. UltraZoom (adaptive beamformer) yielded higher performance than all omnidirectional microphones in moderate background noise for adolescents aged 9 to 15 years. The implications of these data suggest that for older children who are able to reliably use manual controls, UltraZoom will yield significantly higher performance in background noise when the target is in front of the listener.

Notes

Portions of the following data were presented at the 14th International Conference on Cochlear Implants, Toronto, ON, May 11–14, 2016, and at the 15th Symposium on Cochlear Implants in Children, San Francisco, CA, July 26–29, 2017.




Publication History

Publication Date:
02 September 2020 (online)

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