Details

The spectrogram is a classic signal processing technique that shows how the spectral content of a signal changes over time. The horizontal axis represents time (in this implementation time is displayed in milliseconds) while the vertical axis represents frequency (in Hz). The magnitude of each frequency component is shown by the color. With the default "ThermometerColors," large amplitudes are red while small amplitudes are blue, though you can change the color scheme using the "color scheme" dropdown menu. The sound to be analyzed can be any of the curated sounds in the Wolfram library. One slider controls when the display starts and another controls the duration of the display, and the sound can be heard (assuming you have speakers or headphones attached to the computer) by clicking the "play sound" checkbox. Adjacent to this box is a small plot of the time waveform of the signal that is analyzed in the larger display area. The "magnify" slider scales the vertical (frequency) axis and acts as a kind of zoom into the low frequency region. Finally, the plot can displayed as an ArrayPlot, a MatrixPlot, a ReliefPlot, or a ContourPlot.