pitch analysis by raw cross-correlation

## Purpose

to perform a pitch analysis based on a cross-correlation method.

## Usage

Raw cross-correlation is the pitch analysis method of choice if you want to do voice analysis (e.g. jitter, shimmer).

Note that the preferred method for speech (intonation, vocal fold vibration) is pitch analysis by filtered autocorrelation. Raw cross-correlation is mainly for experimenting, or for applications where you need short time windows; for this latter reason, it is also the standard method for voice analysis.

See how to choose a pitch analysis method for details.

## Algorithm

The algorithm performs an acoustic periodicity detection on the basis of a forward cross-correlation analysis.

## Settings

Several settings are already described in Intro 4.2. Configuring the pitch contour. The explanations below assume that you have gone through that part of the Intro.

Time step (s) (standard value: 0.0)
  the measurement interval (frame duration), in seconds. If you supply 0, Praat will use a time step of 0.25 / (pitch floor), e.g. 0.00333333 seconds if the pitch floor is 75 Hz; in this example, Praat computes 300 pitch values per second.
Pitch floor (Hz) (standard value: 75 Hz)
  candidates below this frequency will not be recruited. This parameter determines the length of the analysis window: it will be 1 longest period long, i.e., if the pitch floor is 75 Hz, the window will be 1/75 = 0.01333333 seconds long.

Note that if you set the time step to zero, the analysis windows for consecutive measurements will overlap appreciably: Praat will always compute 4 pitch values within one window length, i.e., the degree of oversampling is 4.

The other settings are the same as for pitch analysis by raw autocorrelation.

## Availability in Praat

Pitch analysis by raw cross-correlation is available in two ways in Praat:

  • via Sound: To Pitch (raw cross-correlation)... from the Analyse periodicity menu in the Objects window when you select a Sound object;
  • via Show Pitch and Pitch analysis method is raw cross-correlation from the Pitch menu when you are viewing a Sound or TextGrid object (SoundEditor, TextGridEditor).

### Links to this page

- FAQ: Pitch analysis
- pitch analysis by filtered cross-correlation
- Pitch settings...