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Development of a Power Efficient Hearing Aid Using MEMS Microphone

  • Souvik Mallik
  • Debjyoti Chowdhury
  • Madhurima ChattopadhyayEmail author
Conference paper
Part of the Communications in Computer and Information Science book series (CCIS, volume 836)

Abstract

In this paper, MEMS based capacitive microphone is designed for low cost power efficient hearing aid application. The developed microphone along with the associated circuitry is mounted at the back of the human ear in form of a wearable device. The designed microphone consists of a flexible circular silicon nitrite (Si3N4) diaphragm and a polysilicon perforated back plate with air as dielectric between them. The incident acoustic waves on the sensor cause deflection of the diaphragm to alter the air gap between the perforated back plate (fixed electrode) and the diaphragm (moving plate) which causes a change in capacitance. The acoustic pressure applied to the microphone is from 0 Pa to 100 Pa for an operating range of 100 Hz–10 kHz which corresponds to the audible frequency range in case of human beings. The main purpose of this work is to increase the longevity of battery used in conventional hearing aids. The designed MEMS microphone with Si3N4 diaphragm is capable of identifying acoustic frequencies (100 Hz to 10 kHz) which corresponds to a specific change in absolute pressure from 0 Pa to 100 Pa for 2 micron thick diaphragm with a sensitivity of about 0.08676 mV/Pa. The design of the sensor and the characteristics analysis are performed in FEM based simulation software which are later validated in real time.

Keywords

MEMS Microphone Circular diaphragm FEM Hearing aid Low power 

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Copyright information

© Springer Nature Singapore Pte Ltd. 2018

Authors and Affiliations

  • Souvik Mallik
    • 1
  • Debjyoti Chowdhury
    • 1
  • Madhurima Chattopadhyay
    • 1
    Email author
  1. 1.Applied Electronics and InstrumentationHeritage Institute of TechnologyKolkataIndia

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