Topics Map > Software Guides > Audacity
Audacity: Volume Adjustments - Keyframing for Ducking and Fading
Audacity, Version: 2.3.2. Be aware that different versions of Audacity will vary in appearance and functionality. Full Guide: View/Download
Audio ducking refers to the practice of lowering the volume of a background music track while people are speaking, to ensure the dialogue can be heard. Ducking in Audacity is achieved through a process called keyframing. A keyframe is like a snapshot of the volume at a single moment; when multiple keyframes are at different volume levels, Audacity automatically transitions the volume between them. Keyframing is done with the Envelope Tool.
To duck audio with keyframing:
- Select the Envelope Tool; bluish-purple lines will appear on the top and bottom of tracks in the Timeline.
- Click on the track to create four keyframes for each section to be ducked. Each keyframe looks like four vertically-stacked white dots.
- 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
- Click-and-drag the white dots on the keyframes to reposition. The waveform height will adjust accordingly.
- Move keyframes vertically to decrease/increase volume.
- Move keyframes horizontally to change timing. Keyframes close together will be a quick change in volume; keyframes further apart will be a slow change.
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
Fades in/out can be created using keyframes (explained in the above section) as well as with the Fade In/Out Effects. The Fade In/Out Effects are not recommended as these actions are impossible to undo later on.
To fade with keyframes:
- Create two keyframes.
- 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:
- With the Selection Tool, click-and-drag to highlight the desired section to be faded in/out.
- Navigate to Effect > Fade In/Out.
Guide Index:
- Audacity: Information
- Audacity: Downloading & Installing for Mac
- Audacity: Downloading & Installing for Windows
- Audacity: Setting Up and Saving Projects
- Audacity: Interface Overview & Tools
- Audacity: Recording Audio
- Audacity: The Timeline & Tracks
- Audacity: Importing Audio Files
- Audacity: Editing Audio
- Audacity: Volume Adjustments - Amplify
- Audacity: Volume Adjustments - Compressor
- Audacity: Volume Adjustments - Keyframing for Ducking and Fading
- Audacity: Splitting & Panning Tracks
- Audacity: Removing Background Noise
- Audacity: Sharing Projects
- Audacity: Exporting an Audio File (MP3, WAV, etc)