You might have heard about audio spectrogram before, but how well do you know about it? If you want to unveil the mystery of the audio spectrogram, then you must spare a few minutes and read on this article…

Basically, the spectrogram is the result of calculating the frequency spectrum of windowed frames of a compound signal. It is a three-dimensional plot of energy of the frequency content of a signal as it changes over time. Spectrogram is mostly being used to identify phonetic sounds, especially to analyze the cries of animals and in the fields of music, sonar/radar and much more.

A Spectrogram is also known as a spectral waterfall, sonogram, voiceprint or voicegram and the instrument that generates the spectrograms is called a sonograph.

The Real Time Spectrogram can be used to compute and display the frequency spectrum of an audio signal on a standard VGA display. The frequency content that displayed on the spectrogram can be computed using two different methods, Fourier transform and Bandpass filters. For the most part, if the combination of the bandpass IIR filters and the display works well, then you’ll see the beautiful sonograph shown on the VGA display!