Contents
Sound & Color - Using Spectrograms to Analyze Sound Signals
By: Emma Gihl
Background
A spectrogram is the visual representation of the frequency changes in a signal as they vary with time. This image can be useful when analyzing changes in frequency that cannot be easily seen in waveform view. A spectrogram is created by taking the DTFT at a certain time and displaying it vertically. This is done repeatedly to create the overall image. Spectrograms can be manipulated to analyze specific signal properties by altering the DTFT used to create it.
Wideband spectrograms limit the time window to about the length of one period for the DTFT. This increases resolution in the time domain and decreases it in the frequency domain.
Narrowband spectrograms use a longer DTFT that covers several periods of the signal. This increases resolution in the frequency domain and decreases it in the time domain.
Processing Your Signal
Displaying Your Signal
Conclusion
Sources
[1] Understanding Spectrograms : https://www.izotope.com/en/community/blog/tips-tutorials/2014/09/understanding-spectrograms.html
[2] Lab 9a Speech Processing : https://engineering.purdue.edu/VISE/ee438L/lab9/pdf/lab9a.pdf
[3]
