A Novel Structure of Electromagnetic MEMS Speaker for Hearing Aid Application

A novel structure for this microspeaker is composed of permanent magnet Neodymium Iron Boron (NdFeB) with the magnetization of 1.42 T, diameter 1.6 mm, a thickness 0.8 mm is bonded on the PDMS membrane and N-copper planar coil is fixed on the bottom wafer. The total size of the PDMS membrane is 3 × 3 mm
²
and thickness 130 μm. The proposed microspeaker is designed for CIC (completely in canal) type hearing aid. The calculation results successfully confirmed that the proposed MEMS microspeaker have a better of electroacoustic performance and efficiency. The sound pressure level (SPL) is 99 dB and the maximum displacement is 5.8 μm at the resonance frequency of 630 Hz with the microspeaker efficiency is 0.06%. In addition, the aim of this structure is to get the low resonance frequency and high acoustic efficiency is validated.