You can adjust the volume level of a whole
clip or track, or have the volume change over time using the rubberband
in an audio track of the Timeline panel.
Expand
the audio track’s view by clicking the triangle next to the audio
track name.
In the audio track header, click the Show Keyframes button , and
choose one of the following from the pop‑up menu:
Show Clip Keyframes
Lets you animate audio effects for a clip, including Volume
Level.
Show Clip Volume
Lets you change only a clip’s Volume Level.
Show Track Keyframes
Lets you animate many audio track effects, including Volume,
Mute, and Balance.
Show Track Volume
Lets you change only a track’s volume level.
If one of the Keyframes settings is selected, do one
of the following:
If Show Clip Keyframes is selected, choose
Volume > Level from the drop-down menu at the head of the clip
in the audio track.
If Show Track Keyframes is selected, choose Track
> Volume from the drop-down menu at the head of the clip in the
audio track.
Note: Volume adjustment should be enabled by default.
Use either the Selection tool or the Pen tool to move
the Volume level rubberband up (increase volume) or down (decrease
volume).
Note: If you want the Volume effect to change over time, place
the current-time indicator at
the location for each change, click the Add/Remove Keyframe button in
the audio track header, and drag the keyframe up (louder) or down (quieter).