Tutorial - Punch-in repair of recordings

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This mini-tutorial describes a simple technique for making a "punch-in" to make a correction to a part of a recording., useful when you make a short fluff or cough.
Bulb icon Good Practice Tip: Always make a backup copy of a recording by exporting it as WAV or FLAC, immediately after you stop the recording, before you work on the punch-in.

To "punch-in" a correction to a recorded track, we use a new track for each take. This allows us to hear a "lead in" and "lead out" (pre-roll / post roll) and, if necessary, to make multiple attempts at correcting, from which we can select and use the one that we like best.

Step 1: Backup the track

The first thing to do is to make a backup copy of the track, so that if you mess up, you have something to go back to.

In this illustration the track has been duplicated, using the Ctrl + D shortcut, and muted using the Mute button. The backup copy is muted so that it won't play.

You may find it useful to collapse this track to save screen space by clicking the Track Collapse button Track Collapse button.png.

In the example the part to be changed is marked with a label, which is not really necessary, but is for illustration purposes.

Punch-in tracks000.png

The "bad part" has been silenced. The easiest way to do this is to select the bad part, then use the Ctrl + L shortcut.

But only do this in the working copy of the track - be careful not to edit the muted backup copy.

Step 2: Overdub

Ensure that you have Audacity set for overdubbing in the Recording Preferences (this is the default setting).

Also ensure there that "Software Playthrough" is turned off (default setting).

Bulb icon As you will be using overdubbing, ensure that you have made the necessary Latency correction setting

Step 3: Lead-in Lead-out

Next you need to extend the selection a bit so that there is some lead-in/lead-out (pre-roll/post-roll):

Punch-in tracks001.png

Step 4: Make the punch-in

And now you are ready to record the "drop in" (punch-in).

Bulb icon Tip: For working with multi-track projects, it can be useful to set the Solo button behavior to "Multi-track" in Tracks Behaviors Preferences

You will need to record on a new track, so just hold down the Shift button and the Record button will change to the alternate The Record New Track button Record New Track button.

Now click that Record New Track button (or use the Shift + R shortcut) and Audacity will start recording on a new track, and will stop automatically when it reaches the end of the selection.

Punch-in tracks002.png

Step 5: Audition your punch-in repair

Now is the time to listen to the punch-in repair you have made.

Select around your punch-in repair (leaving the backup track muted) and press the The Play button play button.

If you are happy with the repair you can delete the backup track from the project.

Optional extras

  • You don't have to mix down the tracks as they will be mixed down automatically on export (muted tracks are not included in the mix), but if you want to mix the tracks, select the tracks that you want to mix down and use Tracks > Mix > Mix and Render.
  • If you want to practice the drop-in before recording it, just use the The Play buttonplay button space rather than the record button.
  • After the recording stops, press Space to listen back to it. If you're not happy, us shortcut Ctrl+Z to undo.
  • If your timing is slightly off, you can use the Time Shift tool, in the Tools Toolbar, to adjust the position of the new clip.
  • The dropped in recording has some lead-in/lead out silence, which may contain noise. That can be trimmed, faded, or fully silenced if required.
  • For some types of recording, crossfading between the original recording and the punch track can help to create seamless edits.