Examples of Ways to Easily Edit Audio

As you work with audio, you may find it helpful to read through these two examples of ways you can fix audio issues using Final Cut Pro.

Example: Replacing Unwanted Audio with Room Tone

As you edit dialogue, you’ll often need to cut out pieces of audio that you don’t want in the sequence. For example, the director may have given directions in between an actor’s lines, or the sound recordist might have bumped into something while shooting on location for a documentary. As long as there’s no dialogue happening at the same time, it’s pretty easy to cut out unwanted sounds. If you simply delete the sound, however, you’ll be left with a gap in your audio that sounds artificial. Since there’s always a low level of background noise, known as room tone, in any recording, a moment of complete silence is jarring.

In order to edit out unwanted sections of audio without creating obvious gaps, it’s common practice to record a certain amount of room tone during a shoot. The recordist simply has everyone stand quietly for thirty seconds or so, and records the ambient sound of the room. If you’ve recorded some room tone during your shoot, you can capture it so that, as you edit, you have a long piece of “silence” that you can edit in whenever you need to cover a gap in the location audio.

If, for some reason, room tone was not captured for a particular scene, but you have a gap you need to fill, you can try to copy a section from another clip in the same scene that has a pause in the dialogue, and paste it to fill the gap. If you have no pauses that are long enough to cover your gap, you can try to copy and paste a short pause multiple times. But there’s a chance that it will end up sounding like a loop, which will be too noticeable. In this case, you can use the following method to obtain a long section of room tone from a short copied pause in the dialogue.

To create a section of room tone from a short pause
  1. Find the longest pause you can in the dialogue clip with the gap you need to fill, then copy the section that contains the pause. If you’re in the Timeline, you can use the Range Selection tool.

    Figure. Timeline window showing a long pause selected in an audio clip.
  2. Create a new sequence, name it “Room Tone,” and paste the audio pause into it twice.

    Figure. Timeline window showing a pause section pasted twice into a new sequence.
  3. Select the clip containing the second pause, then choose Modify > Speed.

  4. In the Speed dialog, click the Reverse checkbox to select it.

    Figure. Speed dialog showing the Reverse checkbox selected.
  5. Play the resulting clips.

    The looping sound should be gone, but if you hear a clicking at the edit point between the two clips, you may have to add a cross fade transition between them to smooth this out. For more information, see Adding Transitions.

    If the looping effect is not obvious, you may want to skip the speed reversal step. You may also need a longer section of ambient tone, or several different sections. Experiment to see what works best.

  6. Cut and paste as many pairs of these clips as you need to fill the necessary duration, adding cross fades between each pair.

  7. Render the Room Tone sequence, then edit the sequence into the gap in your program, just as you would a clip.

    Figure. Timeline window showing a room tone sequence edited into an existing sequence to fill a gap.
To replace an unwanted section of an audio clip with room tone
  1. Make the tracks that contain the unwanted audio the audio destination tracks, then disconnect the video destination track.

  2. Play your clip using the J, K, and L keys, and set In and Out points right before and after the section of audio you want to replace.

    Figure. Timeline window showing In and Out points set to mark a section of audio to be replaced.
  3. Move the Canvas or Timeline playhead to the In point.

  4. Drag your Room Tone sequence into the Viewer, and move the Viewer playhead to the start of the section of room tone you want to use.

  5. Set an In point in the Viewer.

  6. Edit the room tone into your sequence by doing one of the following:

    • Drag the Room Tone sequence from the Viewer to the Overwrite section of the Edit Overlay in the Canvas.

    • Click the Overwrite button in the Canvas.

    • Press F10.

      Figure. Timeline window showing a section of unwanted audio replaced with room tone.

Example: Fixing Awkward Audio Cuts in the Timeline

Once you’ve edited a group of clips into a sequence in the Timeline, you can adjust the edit points between audio items without affecting their corresponding video items. To do so, you turn off linked selection. For example, suppose you’re cutting between two people having a conversation. The first person says something, and then the second person pauses for a moment and replies. It might look something like this:

Figure. Timeline window showing audio being cut off in an outgoing clip followed by an incoming clip with quiet audio.

The timing of the video is what you wanted, but as the audio waveform shows, the last syllable of the last word of dialogue in the first shot gets cut off, which sounds awkward. To fix this, you can create a small split edit in the Timeline. (A split edit has different video and audio In and Out points. See Split Edits.)

To fix an awkward audio cut in the Timeline
  1. Turn off linked selection by doing one of the following:

    • Click the Linked Selection button (or press Shift-L) so that it’s off.

      For more information, see Linking Video and Audio Clip Items.

    • Click the edit point between the two audio items while holding down the Option key.

  2. Select the Roll tool from the Tool palette (or press the R key).

    Figure. Tool palette showing the Roll tool.
  3. Drag the audio edit point to the right so that the entire word plays at the end of the first clip.

    Figure. Timeline window showing the audio edit point after it is dragged to the right.

Now when you play through this cut, you can hear all of the words the first person is saying, and then the second person’s reply.