You can include audio in video ads by adding audio clips. Along with the standard media clip functionality, you can monitor and adjust the volume levels of your audio.
Missing audio controls
If you can't see the peak meters, volume slider, envelope line or waveforms for an audio track, expand the height of the track by dragging its bottom edge downward.
Preview audio
You can listen to your video document's audio by previewing the document. Press the Play button in the timeline controls.
During preview playback, you can see the current decibel level of any audio in multiple peak meters:
- One for each audio track, on the left side of the timeline
- One for overall audio, including any volume adjustments and fade transitions, on the right side of the timeline (collapsible by clicking the collapse
button)
Peak meters measure the volume in decibels relative to full scale (dBFS), with 0 dBFS as the maximum level. Each peak meter has the following components:
- Current decibel level, shown as coloured bars
- Most recent maximum level (reset every 1.5 seconds), shown as yellow lines past the coloured bars
- Clipping indicator, shown as red indicators at the end of the peak meter; these remain visible throughout playback if the decibel level ever exceeds the maximum
Peak meters are only active during preview playback.
Adjust audio volume
You can change the volume of audio for an entire track or during a clip.
Track volume
Adjust the base volume for an audio track by using the volume slider under the track's peak meter in the timeline or clicking the decibel value and entering a new one. Dragging the slider all the way to the left (to -Infinity dB) will mute the track.
Clip volume
You can set the volume of a clip at any given time with volume envelopes, indicated by horizontal lines within each audio clip. The height of the envelope line indicates the volume level at that point in the clip.
The volume changes that you make to an audio clip are relative to the base volume that you set for the audio track.
Envelope lines with no nodes
By default, audio clips display a horizontal envelope line with no nodes. You can drag this line upwards or downwards to change the clip volume. Move the line to the bottom of the track to mute the clip.
If there are no envelope nodes in a clip, you can add a fade transition at either end of the clip by hovering over the clip, then clicking the Add transition 
Adding nodes
To set the volume at a specific point within a clip, add a node. Right-click the envelope line where you want to place the node, then select Add node from the pop-up menu. You'll want to add at least two nodes to a clip in order to change the volume between them.
Moving nodes
Drag a node vertically to adjust the volume or horizontally to change the timing of the volume change. To help you sync the timing of volume changes, nodes can snap to clip boundaries, keyframes from all tracks, the playhead and preview range handles. Nodes can't be dragged past each other.
Besides moving nodes individually, you can drag the envelope line between two nodes upwards or downwards. This changes the volume at both nodes simultaneously.
Volume transitions
You can change the shape of the envelope line between two nodes to apply different types of transitions from one volume level to the next. Right-click the first node and select a fade type from the pop-up menu:
Linear (default)
Fast
Slow
Smooth
Sharp
Hold
Removing nodes
Remove a node by right-clicking and selecting Remove. You can delete all nodes from a clip by selecting Remove all.
Trimmed clips will lose any nodes in the trimmed section. Split clips (including from a frame hold) will add a node at the split point with a linear fade.
Envelope shapes will automatically adjust for any node changes.
Mute audio
You can mute an entire audio track by clicking the Mute button. This mutes the track both in the preview and in published files. You can't edit the volume in muted tracks.
If you want to mute an audio clip, drag its envelope line to the bottom of the track.