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Audacity: Fading & Adjust Volume in Specific Sections (Keyframing)

Audacity, Version: 3.1.3. Be aware that different versions of Audacity will vary in appearance and functionality.



Keyframing is an audio editing technique that automates volume changes, such as fading audio in and out. For example, keyframing can be used to fade out a music track in order to hear other audio clips, such as dialogue or voiceover.

A keyframe is like a snapshot of the volume at a single moment; when multiple keyframes are at different volume levels, Audacity automatically increases/decreases the volume between them. At least two keyframes are required for each fade: to start the fade, as well as to end the fade. Keyframing is done with the Envelope Tool.

To automate volume changes and create fades:
  1. Switch to the Envelope Tool, which looks like two stacked triangles with a line in between. Volume control lines, which are blue, will appear along the top and bottom of the clips in the Timeline.

  2. Click on the volume control line for a clip. A keyframe, which has four white handles, will appear.

  3. Move the cursor to a different time of the clip, and click the volume control line again. Another keyframe will appear.
  4. Click-and-drag the handles of the keyframes up/down to increase/decrease the volume.

  5. Repeat steps 3 and 4 to add the desired keyframes.
  6. When done, switch back to the Selection Tool to exit keyframing. Keyframes can be modified again at any time with the Envelope Tool.

The example below shows a clip that fades out, and then back in.
  • Keyframe 1: start of the fade-out
  • Keyframe 2: low background volume (during dialogue)
  • Keyframe 3: start of the fade-in
  • Keyframe 4: back to full volume
To modify the timing of the volume change, click-and-drag the keyframes and move them left or right. A smaller distance between keyframes will create a shorter fade, whereas keyframes farther apart will create a longer fade.

To delete a keyframe, click-and-drag it outside of the track; upon the release of the computer mouse the keyframe will disappear.

Fade In/Out Effects

We recommend using keyframing to create any automated volume changes and fades However, the Fade In/Out effect may be useful in some situations. Be aware that the Fade In/Out effect is permanent and can’t be undone later, whereas keyframes are always accessible with the Envelope Tool. These effects will also completely fade the audio to 0%. Use the Fade In/Out effects with caution. 

To fade with keyframes:
  1. Create two keyframes.
  2. Click-and-drag one of the keyframes inwards to decrease its volume.
    • Fade-in: adjust the first keyframe
    • Fade-out: adjust the second keyframe

To fade with Fade In/Out Effects:
  1. With the Selection Tool, click-and-drag to highlight the desired section to be faded in/out.
  2. Navigate to Effect > Fade In/Out.



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Keywords:Audacity, workshop, software, production, guide, editing, audio, volume, ducking, keyframing   Doc ID:86090
Owner:Misty B.Group:Pacific Lutheran University
Created:2018-09-27 12:13 PDTUpdated:2022-04-12 10:31 PDT
Sites:Pacific Lutheran University
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