"Change Pitch" is changing tempo and inserting silence

Special Interest Groups Audio Processing
1

Hi, I’m trying to adjust the pitch on individual vocal notes on a singing track. The “Change Pitch (wthout changing tempo)” effect is changing the length of the track and sometimes inserting silence. Any ideas on how to fix this or work around it? These are subtile little pitch corrections. I’m using version 1.3.5 on Windows XP.

Thanks.

2

Yes, there is often a small change in the length of the processed audio with this effect (a limitation of the algorithm that is used). The workaround is to copy the section that you want to process onto a new track (select the note, then press Ctrl+D). Then process the note that is on the new track. To replace the original note with the new note, use the envelope tool (“F2” key) to fade out the original note and fade in the new note. Using a short cross fade in this way you should be able to make the “patch” seamless.

Tip: Switching between the “Waveform” and the “Waveform (dB)” views can help when adjusting the envelope.
Here’s an example. The upper (original) track is shown in the “Waveform” view, and the lower (pitch corrected) track is shown in the “Waveform (dB)” view.
pitch_correct.png

3

For a “quick and dirty” method using Audacity 1.3.6, instead of cross fading,

  1. trim the silence off the end of the processed track
  2. double click on the processed audio clip to select it.
  3. press the Enter key to unselect it
  4. press the “up cursor” key to move focus to the original track
  5. press the Enter key to select the same region on this track
  6. press the Ctrl+L keys to silence the selected region

You may get a very small click at the join using this method, but it is much quicker than messing with the envelopes.
A lot of the time the join will still be undetectable.