I am designing a circuit to amplify audio from microphone as well as removing dc offset from biasing the microphone. I searched for circuits available online for my personal project. I came across circuit from Sparkfun. I understood everything except the capacitor and resistor connected to non-inverting terminal of op-amp. Please explain the use of the capacitor
C2 in the above schematic and why it is connected with the resistors
Also, I am going to convert the analog signal after amplification to digital form using ADC. I want suggestion on bit resolution for audio applications that will provide acceptable voice quality during recreation of the voice.
Here is the schematic from the Sparkfun web site shared under the Creative Commons license.