Short-Time Fourier Transform

The Short-Time Fourier Transform (STFT) is an analysis tool that repeatedly applies the Discrete Fourier Transform (DFT or FFT) to short snippets of a longer signal, while sliding the window that selects the snippet of the longer signal that the STFT operates on. The STFT is a function of two independent variables, frequency in the DFT and the time of the center of the sliding window.