MEMS speaker and speaker assembly structure

A Micro-Electro-Mechanical-Systems (MEMS) speaker, comprising:

• a substrate;
• a vibration sounding portion;
• and
• a baffle plate;
• wherein a first end and a second end of the substrate are open and the substrate is a hollow shape;
• the vibration sounding portion is configured to emit a sound wave within a range of human ear auditory frequency when excited by an electrical signal, and the vibration sounding portion is fixed to and covered on the first end of the substrate, and the sound wave generated by vibration of the vibration sounding portion conforms to a classical sound wave theorem;
• the baffle plate is covered and fixed on the second end of the substrate;
• the baffle plate, the substrate, and the vibration sounding portion together form a sounding inner cavity, a volume of the sounding inner cavity is configured to adjust a resonance frequency of the sounding inner cavity, so that the resonance frequency of the sounding inner cavity resonates with a preset frequency of the MEMS speaker;
• a through hole is defined on the baffle plate, the sounding inner cavity communicates with an outside world through the through hole, and a volume of the through hole is configured to adjust a sound pressure level and harmonic distortion of the MEMS speaker within a working frequency range.