Time Stretching a Signal

Time Stretching allows you to change the signal duration without altering the pitch.

To Time Stretch a Signal:

  1. In Tools, choose Time Stretch > Full Signal or Selection.
  2. In the Time Stretch parameters box, set the Dilation ratio > 1 to increase the length of the signal or < 1 to decrease the length of the signal.

    For example, setting a ratio of 2 makes a signal twice longer than the original.

    For example, setting a ratio of 0.5 makes a signal twice shorter than the original.

  3. If needed, enable the Advanced parameters and,

    • In Window size, set the length of the window used by the phase vocoder algorithm.

    • Set the windows Overlap.

    • Enable Phase Lock to activate the specific processing for linking the phases along pure tones.

      The signal duration is modified.

      Note: Very large or very small dilation ratios may result in a degradation of audio quality.

      In some cases, experimentation with the advanced parameters can help to achieve better quality.

      Time Stretching is not suited to very short signals and to very short transient/shocks events. If you need to time stretch a very short signal, you should set a short window size and disable the Phase Lock option. Final result quality is not ensured for these kinds of signals.