STFT to spectrogram

1. What is STFT spectrogram?
2. Is STFT and FFT same?
3. Why would we use a STFT spectrogram for Analysing human speech?

What is STFT spectrogram?

s = spectrogram( x ) returns the Short-Time Fourier Transform (STFT) of the input signal x . Each column of s contains an estimate of the short-term, time-localized frequency content of x . The magnitude squared of s is known as the spectrogram time-frequency representation of x [1].

Is STFT and FFT same?

If you look closely, there is a difference in the time frame on 3D graphs between STFT and FFT. STFT has smaller time frames, consequently, the frequency spectrum moves smoother over time, therefore it is more accurate. Block size - defines the number of real data samples to be taken for the calculating FFT.

Why would we use a STFT spectrogram for Analysing human speech?

The STFT is one of the most frequently used tools in speech analysis and processing. It describes the evolution of frequency components over time. Like the spectrum itself, one of the benefits of STFTs is that its parameters have a physical and intuitive interpretation.