Acoustic-electric conversion structure, electric signal amplification circuit and dual-mode microphone

The invention relates to an acoustic-electric conversion structure, an electric signal amplification circuit and a dual-mode microphone, and belongs to the technical field of acoustic-electric conversion; the acoustic-electric conversion structure comprises: a magnetic steel which is used for generating magnetic lines; an electret back polar plate which is arranged at one end of the magnetic steel and is used for storing charges; a composite vibrating diaphragm which is arranged at one end, far away from the magnetic steel, of the electret back polar plate, and a gap for the composite vibrating diaphragm to move towards the electret back polar plate is reserved between the composite vibrating diaphragm and the electret back polar plate, and wherein the composite vibrating diaphragm comprises a metal coating and a polymer vibrating diaphragm material layer, and the metal coating is arranged close to the electret back polar plate; a voice coil which is arranged on the composite vibrating diaphragm and can gener