Quantify the difference between two audio spectrograms

1. How do you compare two spectrograms?
2. What information one can get from spectrogram of speech signal?
3. What is an FFT spectrogram?

How do you compare two spectrograms?

You could subtract the two waveforms and get the spectrogram of the difference. In theory it should be the same as what you asked for. To do this you need to invert one of the tracks and mix(add) them in equal volume.

What information one can get from spectrogram of speech signal?

A spectrogram is a visual way of representing the signal strength, or “loudness”, of a signal over time at various frequencies present in a particular waveform. Not only can one see whether there is more or less energy at, for example, 2 Hz vs 10 Hz, but one can also see how energy levels vary over time.

What is an FFT spectrogram?

The FFT Spectrogram trend, sometimes known as a color density spectral array (CDSA), displays a density spectral array of the frequency and power characteristics of the EEG, derived from a fast Fourier transform (FFT) analysis, as a function of time.