How to get the frequency response of a sound file?

Question

Audio

The *.wav format file is created using the NAudio library by recording from a microphone. Actually, how to get the frequency response from the same file, and ideally, it is better to get the frequency response directly from the microphone.

Answer 1

"Direct off the mic" is not quite right. As noted in the comments nehrung , you can analyze the spectrogram of some time range (measurement). That is, you can create a spectrogram based on data in a sliding buffer window received from the source stream.
Search for "FFT" in the NAudio project
NAudioWpfDemo
Yes, and on the project page https://naudio.codeplex.com/ the first two pictures of the demo programs contain a spectrogram.