Apple Final Cut Pro 7 - Manual (Page 126)

126 Chapter 6 Working with Audio
Try This
Increase a clip’s audio level over time using keyframes:
With Audio Clip 1 open in the Audio tab of the Viewer, drag the fader sliders in the
1
Audio Mixer all the way to the bottom to set the audio level at the lowest level possible.
Press Home to position the playhead at the beginning of the clip.
2
Click the Level Keyframe button in the Viewer to add an audio level keyframe to the 3
first frame of the clip.
Level Keyframe button
Position the playhead in the Viewer where you want the audio to reach the maximum 4
level, similar to the playhead position shown below.
Position the playhead here.