Short-Time Analysis, Modification, and Resynthesis

The STFT is the main computational tool used in spectral modeling applications. As we discuss in detail in Chapters 8 and 9, the STFT may be viewed as either an

1. overlap-add processor--a sequence of Fourier transforms of windowed data segments (a ``sliding'' or ``hopping'' FFT), or a
2. filter-bank-sum processor--an implementation of a time-domain bandpass filter bank using an FFT to implement the filter bank.

Most STFT applications are based on the overlap-add point of view. However, the filter-bank-sum viewpoint coincides with earlier precursors such as the phase vocoder (discussed in the applications chapter), and many audio coding schemes have been based on filter banks.