espectrogram

An spectrogram is a visual representation of the spectrum of frequencies of a signal as it varies with time. It is a graphical display that shows how the frequency content of a signal changes over the duration of the signal. Typically, time is plotted on the horizontal axis, frequency on the vertical axis, and the intensity or amplitude of a particular frequency at a particular time is represented by the color or shade of a point.

Spectrograms are commonly used in signal processing, audio analysis, and other fields where understanding the frequency content of a signal over time is important. For example, in acoustics, a spectrogram can reveal the different harmonics and overtones present in a sound, and how they evolve as the sound is played. In speech analysis, spectrograms help in identifying phonemes and understanding the characteristics of different voices. They are also employed in radar and sonar systems to analyze reflected signals and in seismology to study earthquake waves.

The creation of a spectrogram usually involves breaking down the signal into short, overlapping time segments. A Fourier transform, often a Fast Fourier Transform (FFT), is then applied to each segment to determine its frequency spectrum. These individual spectra are then arranged side-by-side to form the complete spectrogram. The choice of window size and overlap in this process can affect the resolution of the spectrogram in both time and frequency.