Electroacoustic Assessment of Wireless Remote Microphone Systems

Abstract

Wireless remote microphones (RMs) transmit the desired acoustic signal to the hearing aid (HA) and facilitate enhanced listening in challenging environments. Fitting and verification of RMs, and benchmarking the relative performance of different RM devices in varied acoustic environments are of significant interest to Audiologists and RM developers. This paper investigates the application of instrumental speech intelligibility and quality metrics for characterizing the RM performance in two acoustic environments with varying amounts of background noise and reverberation. In both environments, two head and torso simulators (HATS) were placed 2 m apart, where one HATS served as the talker and the other served as the listener. Four RM systems were interfaced separately with a HA programmed to match the prescriptive targets for the N4 standard audiogram and placed on the listener HATS. The HA output in varied acoustic conditions was recorded and analyzed offline through computational models predicting speech intelligibility and quality. Results showed performance differences among the four RMs in the presence of noise and/or reverberation, with one RM exhibiting significantly better performance. Clinical implications and applications of these results are discussed.

Fitting Assistive Technology for People with Hearing Loss: The Importance of Remote Microphone Systems′ Electroacoustic Verification

“…In Table 1 , with the transmitter/receiver analysis, we observe that, on the one hand, the frequency of need for gain setting and use of default setting was similar between the RMB and RMA brands; on the other hand, RMC had a higher frequency of need for gain setting. In studies involving the verification of electroacoustic measurements, the authors cite that when transparency values are not achieved with the default setting, they should be adjusted using the receiver gain setting controls that can be activated by the transmitter or the company’s software [ 3 , 9 , 11 , 14 , 23 , 30 ].…”

Toward a Real-World Technical Test Battery for Remote Microphone Systems Used with Hearing Prostheses

“…Although standardization of test methodologies and measures has enabled the production of clinically affordable test boxes, such as for HAs, the methods investigated by us, Salehi et al (2018) and Husstedt et al (2022), require the use of larger, and more specialist, facilities, and equipment. This will limit the widespread uptake of any measures developed from these bodies of work.…”

“…The demonstration of benefits to individuals is seen as a subsequent step to this comparison process. A similar approach has been reported by Salehi et al (2018), also testing in a more realistic acoustic scenario, but they only focused on metrics of intelligibility.…”

Guidelines for Best Practice in the Audiological Management of Adults with Severe and Profound Hearing Loss

“…107 The AAA 102 focuses on hearing-assistive technology for individuals from birth to 21 years. It is based on the American Speech-Language-Hearing Association (2002) guidelines, 108 which focused on real-ear, electroacoustic, and behavioral evaluation procedures. There are specific protocols in Supplement A of the AAA guidelines 102 for the electroacoustic and behavioral evaluation of ear-level remote microphone systems when used with clients who wear hearing aids or cochlear implants or who have normal hearing.…”