J Am Acad Audiol 2020; 31(01): 050-060
DOI: 10.3766/jaaa.18065
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Evaluation of a Remote Microphone System with Tri-Microphone Beamformer

Jace Wolfe
*   Hearts for Hearing Foundation, Oklahoma City, OK
Mila Duke
*   Hearts for Hearing Foundation, Oklahoma City, OK
Erin Schafer
†   Department of Audiology & Speech-Language Pathology, University of North Texas, Denton, TX
Christine Jones
‡   Phonak LLC, Warrenville, IL
Lori Rakita
‡   Phonak LLC, Warrenville, IL
Jarrod Battles
*   Hearts for Hearing Foundation, Oklahoma City, OK
› Author Affiliations
Further Information

Publication History

Publication Date:
25 May 2020 (online)



Children with hearing loss often experience difficulty understanding speech in noisy and reverberant classrooms. Traditional remote microphone use, in which the teacher wears a remote microphone that captures her speech and wirelessly delivers it to radio receivers coupled to a child’s hearing aids, is often ineffective for small-group listening and learning activities. A potential solution is to place a remote microphone in the middle of the desk used for small-group learning situations to capture the speech of the peers around the desk and wirelessly deliver the speech to the child’s hearing aids.


The objective of this study was to compare speech recognition of children using hearing aids across three conditions: (1) hearing aid in an omnidirectional microphone mode (HA-O), (2) hearing aid with automatic activation of a directional microphone (HA-ADM) (i.e., the hearing aid automatically switches in noisy environments from omnidirectional mode to a directional mode with a cardioid polar plot pattern), and (3) HA-ADM with simultaneous use of a remote microphone (RM) in a “Small Group” mode (HA-ADM-RM). The Small Group mode is designed to pick up multiple near-field talkers. An additional objective of this study was to compare the subjective listening preferences of children between the HA-ADM and HA-ADM-RM conditions.

Research Design:

A single-group, repeated measures design was used to evaluate performance differences obtained in the three technology conditions. Sentence recognition in noise was assessed in a classroom setting with each technology, while sentences were presented at a fixed level from three different loudspeakers surrounding a desk (0, 90, and 270° azimuth) at which the participant was seated. This arrangement was intended to simulate a small-group classroom learning activity.

Study Sample:

Fifteen children with moderate to moderately severe hearing loss.

Data Collection and Analysis:

Speech recognition was evaluated in the three hearing technology conditions, and subjective auditory preference was evaluated in the HA-ADM and HA-ADM-RM conditions.


The use of the remote microphone system in the Small Group mode resulted in a statistically significant improvement in sentence recognition in noise of 24 and 21 percentage points compared with the HA-O and HA-ADM conditions, respectively (individual benefit ranged from −8.6 to 61.1 and 3.4 to 44 percentage points, respectively). There was not a significant difference in sentence recognition in noise between the HA-O and HA-ADM conditions when the remote microphone system was not in use. Eleven of the 14 participants who completed the subjective rating scale reported at least a slight preference for the use of the remote microphone system in the Small Group mode.


Objective and subjective measures of sentence recognition indicated that use of remote microphone technology with the Small Group mode may improve hearing performance in small-group learning activities. Sentence recognition in noise improved by 24 percentage points compared to the HA-O condition, and children expressed a preference for the use of the remote microphone Small Group technology regarding listening comfort, sound quality, speech intelligibility, background noise reduction, and overall listening experience.

This research was partially funded by a grant from Phonak, LLC. These data have not been presented in any other journal or at any professional meeting.


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