Pitch

Extracts the fundamental frequency over the selected range of low frequency and high frequency. The results are displayed into a separate, resizable window. The format of the pitch display is set by the settings in the Pitch Options. This window will duplicate the zooming and scrolling mechanism of the main window. You can play sound (all, window or selection) through this window as well as the main window. The pitch log entry is supported in this window.

The audio along with the intensity traces can be displayed on the top of the pitch for references. The intensity display in the pitch window is calculated only in the "Absolute" mode.

Two pitch extraction methods are available:

- Cepstral algorithm is a powerful analysis, developed by SCICON R&D Inc.. No data smoothing or interpolation is performed. The reported pitch data is the actual calculated values. This process is sensitive to threshold level and the frequency deviation. To get smoother pitch tracks, lower the frequency deviation and/or lower the threshold in the Pitch Options. Reducing the step size reports more frequent pitch values at the expense of much longer calculation time.

- Autocorrelation algorithm is a basic time resolved windowing for pitch estimation. The reported data is highly smoothed and interpolated for best and smoothest result.

After changing any parameters, a new pitch operation must be made to reflect the new changes.

We have successfully tested this algorithm in ranges as high as 800 Hz (for children).

The Pitch Options offers a variety of controls. Experimentation with varying various parameters is highly advised to get the best result.

Hints for pitch tracking

:

Use 11 KHZ sample rate.

Using 22 KHZ sampling rate may result in degradation of the tracking.

TRY NOT USING 44 KHZ

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Use 35-45 ms window length for male speakers.

Use 15-25 ms window length for female speakers.

Set the threshold level to about 2-3 %. For noisy signals increase the threshold level to about 5%.

Set the frequency deviation to about 40-50 Hz.

Adjust the frequency calculation range to the range of interest.