Directional microphone module

A directional microphone module, comprising:

• a sound-permeable mesh;
• a housing, engaged with the sound-permeable mesh for forming a containing space;
• a circuit board, disposed in the containing space and fixed to the housing;
• and
• a MEMS microphone, disposed in the containing space and fixed to the circuit board, wherein
• the housing comprises a top wall spaced apart from the sound-permeable mesh and a side wall extending from the top wall and fixed to the sound-permeable mesh, the circuit board is arranged between the top wall and the sound-permeable mesh, the circuit board and the top wall are spaced for forming a first cavity, the circuit board and the sound-permeable mesh are spaced for forming a second cavity, the side wall comprises two first walls disposed opposite to each other and two second walls disposed opposite to each other and connecting the two first walls, the first cavity and the second cavity are only communicated at a position adjacent to one of the two second walls, the MEMS microphone is disposed in the first cavity and locates at a position adjacent to another second wall, the MEMS microphone comprises a first acoustic hole facing the top wall and a second acoustic hole facing the circuit board, the first acoustic hole communicates with the first cavity, the circuit board is provided with a through hole communicating the second acoustic hole and the second cavity, the second acoustic hole communicates with the second cavity through the through hole, and
• wherein the top wall, the circuit board and the sound-permeable mesh are parallel to each other, a spaced distance between the circuit board and the top wall is equal to a spaced distance between the circuit board and the sound-permeable mesh.