ReSound’s Jennifer Groth and Stephen Hallenbeck recently contributed an article to AudiologyOnline entitled “Evidence-based Design Leads to Remote Microphone Hearing Instrument Technology”. This article discusses the underlying principles that guided the design process of Remote Microphone hearing instrumentation at ReSound.
Remote Microphone design works by placing the microphone in the external ear near the concha cymba. It makes use of the natural effects of the pinna as they relate to directivity, high frequency amplification and wind noise reduction. The placement of the microphone in the concha cymba hides the microphone not only for improved cosmetics but also for improved acoustic performance due to pinna effects and protection from turbulent wind noise.
Remote Microphone hearing instruments provide benefit for a wide range of hearing-impaired patients. Research participants were found to make fewer localization errors when fit with Remote Microphone devices than with the typical microphone placement in BTE devices, most likely due to preservation of spectral cues. Speech-recognition-in-noise test results also supported the positive effect of preserving the spectral shaping of the pinna. Research participants who trialed conventional CIC, open fit BTE with directionality, and RM instruments demonstrated similar benefit with each device type. Design characteristics, due to component placement, provide greater flexibility relative to other custom devices when choosing between options such as vent size and power level. Clinical results indicated significantly greater gain before feedback with the Remote Microphone concept than with conventional custom devices for a variety of venting sizes. When fit of the device was controlled in a lab experiment, it was shown that up to 5 dB added stable gain can be expected with Remote Microphone instruments compared to conventional custom devices.
Read the full article at AudiologyOnline.