Audio Effects via STFT Transformations
AudioSpectralMap is a function that allows for modifications of signals in the time-frequency representation of the short-time Fourier transform (STFT). It is easy to manipulate the STFT to reduce the background noise in a time-and-frequency-dependent way.
Start with a noisy audio signal.
Define a function that decreases the amplitude of quiet components.
Apply the function to the STFT using AudioSpectralMap.
AudioSpectralTransformation is another useful function for manipulating signals from a time-frequency representation. It constructs a new signal by computing a backward transformation between the input and output signals' STFTs.
One can create "special effects"—such as fisheye—in the frequency domain by defining such a mapping. Start with an amusing signal.
Define a transformation that creates a fisheye effect.
Apply the function to the input signal using AudioSpectralTransformation.