Audio Short-Time Fourier Transform (STFT)

Frequency changes over time, and therefore an overall Fourier transform is not typically a good representative of the signal. ShortTimeFourier computes a Fourier transform of partitions of a signal, typically known as short-time Fourier transform (STFT). Short-time Fourier transform is heavily used in audio applications such as noise reduction, pitch detection, effects like pitch shifting and many more.

Compute the short-time Fourier transform of an audio recording.

The result is ShortTimeFourierData, which, in addition to the short-time Fourier transform result, contains the parameter used to compute the result to facilitate the reconstruction of the original signal.

Visualize the result using Spectrogram.

A signal can be reconstructed from its short-time Fourier transform using InverseShortTimeFourier. All of the parameters stored in the object allow the function to reconstruct the original signal.

Some of the parameters in ShortTimeFourierData can be modified to change the result of the reconstruction. In this case, you can force the "PartitionOffset" parameter to be bigger than the original to slow down the signal.