Sonogram, Spectral analysis and Wavelet analysis

DataView has time-frequency analysis facilities, including

• Sonogram
  Short-term Fourier transforms allows examination of the time-varying frequency components in a signal. Averaging increases the accuracy of the power measurement of each frequency bin, while partial segment overlapping increases the time resolution of the analysis.

An audio file (wav format) has been loaded into DataView and the time-frequency components are displayed as a sonogram.
Click here to play as web animation (or right-click image and select Play).

 

The sonogram can be displayed in rotatable 3D, which may be informative, and certainly looks nice.

• Spectral analysis
  Standard stationary spectral analysis can be accomplished by selecting a time-slice through the sonogram.

A mixed sine wave containing components at 5, 20 and 100 Hz. 1.2 s of data were sampled at 1 KHz.		The output from stationary spectral analysis shows the 3 frequency components in the data. In order to achieve the required resolution with the available record length, the data were decimated to a frequency of 250 Hz.