CMOS compatible directional microphone

The goal of hearing aids is to selectively attenuate acoustic signal based on the directional of sound arrival. Directional microphone or microphone arrays are used to achieve this goal. The longer distance of microphone pairs is a problem of the application on hearing aids. In this paper, a single directional microphone structure is proposed to solve this problem and can be used in other application. This directional microphone is constructed by the post CMOS MEMS process. The mechanism of this structure is originally inspired the by the ears of fly Ormia ochracea. In the result, the characteristic of this directional microphone is bi-direction pattern.