The Goals of Audio Editing

Most viewers are quite good at distinguishing audio changes from one clip to the next, as well as incorrect audio/video synchronization. As you work on refining the audio in your project, your edits will focus on eliminating these major distractions to the audience. In particular, keep in mind three important goals.

Make sure your audio edit points aren’t noticeable

Editing audio clips in a sequence mainly involves finding good edit points that sound natural. Audio edit points are often more effective when they are offset from the corresponding video edits. Although you may set your initial audio and video edit points in the same place to create a quick rough cut, editing your audio more finely may involve changing many of your edit points to split edits. Some of those split edits may have only a few frames offset between the audio and video edit points, but those frames will turn an otherwise obvious cut into a much smoother transition.

Besides making clean-sounding cuts, there are other reasons to edit the audio in your sequence separately from the video. You can edit mistakes in dialogue, adjust the sync of off-camera or rerecorded dialogue, or even replace the entire audio of a clip with another take of the same audio.

For more information, see Split Edits.

Make sure that your video and audio clips are in sync

As you edit your audio, you may sometimes find it necessary to adjust the sync relationship between video and audio clip items. Audiences are quick to notice when audio is out of sync with the picture, so you need to be extra cautious when you’re editing. Here’s a good rule of thumb: if you’re finding an audio/video sync issue distracting, your audience probably will too. In this case, you should make adjustments.

Final Cut Pro keeps track of the sync between video and audio clip items when they come from the same source media file, or when they have been intentionally linked together. Red out-of-sync indicators on clip items show you exactly how far the items are out of sync. You can establish new sync relationships by selecting the clip items and choosing Modify > Mark in Sync.

For more information about establishing sync between video and audio clip items, see Linking and Editing Video and Audio in Sync.

Minimize differences in tone and quality between audio clips in the same scene

All audio has some kind of background noise, often referred to as ambience or room tone. Sometimes you’ll find that the audio from the different shots you’re using in the same sequence has differences in the background ambience. For example, if you shoot a conversation in a city park, and the shoot lasts all day, you may notice that some shots have more traffic noise in the background because of rush hour. Assuming you don’t want to rerecord the dialogue for the whole scene, you’ll need to edit more “rush hour” background noise into the clips that don’t have any so that all the clips sound the same within the same 2-minute scene. Otherwise, the traffic noise in the background will pop in and out from one shot to the next, which will call attention to your edits and distract the viewer. Usually, the shot with the highest ambient background noise level dictates the ambient noise level for the entire scene.