By Stephen Hallenbeck, Au.D
Hearing aid microphones are susceptible to receiving wind fluctuations and amplifying them as they would any other sound pressure fluctuation, which is why wind noise continues to be a problem. Remote Microphone Technology utilizes the physical and acoustic properties of the outer ear to improve performance in wind noise.
When considering the auditory system, the fact that the middle and inner ear structures are placed deeply relative to the pinna provides a level of natural wind noise reduction. Therefore, a deep microphone placement, such as that used in CIC instruments, can reduce the annoyance of wind noise. In situ measurements indicate the greatest amount of wind noise turbulence typically occurs in the areas behind the pinna while little turbulence is measured in the superior portions of the concha. The placement of the microphone behind the cartilage of the helix and concha inherent in the Remote Microphone design provides a physical barrier protecting the inlet of the microphone from turbulent air flow.
Check back on Wednesday for the impact of Remote Microphone Technology on gain before feedback.