Circuit for audio analysis

The utility model relates to the technical field of audio analysis, in particular to a circuit for audio analysis, which comprises an input end, an impedance switching circuit, an attenuation circuit, an amplification circuit, a shaping circuit, a CPLD (Complex Programmable Logic Device) circuit, an ADC (Analog to Digital Converter) acquisition circuit and a microcontroller. The impedance switching circuit is used for switching the input impedance of the audio analysis circuit to be matched with the superior output impedance, outputting the processed audio signal to the attenuation circuit for attenuation processing, then outputting to the amplification circuit for amplifying the audio signal, and respectively outputting to the shaping circuit and the ADC acquisition circuit; the shaping circuit converts an audio signal into a square wave signal and outputs the square wave signal to the CPLD circuit to calculate a frequency value of the audio signal, and the ADC acquisition circuit is used for performing anal