Table 1.

Comparison among MEMS acoustic sensor types.

MEMS Acoustic Sensor Type	Advantages	Disadvantages
Capacitive	High sensitivity High signal-to-noise ratio Low noise level	Sensitive to environment disturbances (moisture/dust/shock) Bias voltage required
Electret	High sensitivity Low power consumption	Sensitive to environment disturbances High charges required
Electromagnetic	Wide dynamic range Low noise level	Huge volume Low sensitivity
Piezoelectric	High acoustic overload Low power consumption High reliability	High noise level Low sensitivity
Optical	High sensitivity Wide dynamic range Immune to electromagnetic interference	External light source Fabrication and packaging difficulties