Can silenced audio be restored in a project file?

If I have an audio file I have brought into an Audacity project, and I have selected various areas where I have generated silence, can I at at later time restore the audio that was silenced in a specific section? Not in the exported file, of course, but in the project.

Projects do not save UNDO.

Depending on the effect, Audacity saves the whole show as UNDO. Project files would be monstrously large if all the UNDOs were included.


So if I silence a bit of dialog, and I realize later I’ve cut off the initial phoneme of the first word, I can’t fix that? It’s still there in the original audio file. I’ve only silenced it in the project.

I can’t fix that? It’s still there in the original audio file. I’ve only silenced it in the project.

Right, so you can mount the original file as a second track, slide it into position using the Time Shift Tool (two sideways black arrows)…

…and use Envelope Tool…

… to silence everything that’s not valuable. Audacity will play everything at once and export it all as one song unless you stop it.

If you changed timing in addition to muting portions of the show, it could get a lot more interesting.


I’m not “Mr. Editing,” but I know a common error is to try and fix a problem similar to yours by editing directly in a song or other performance on a single timeline. Because of timing difficulties and other errors, you end up constantly mopping up after yourself.

Much better to do it in two different tracks.

Others may post.


Audacity could be described as a “WYSIWYG” editor. When you apply an edit or process a track, the action is applied immediately and you can see the result.
This contrasts with “Real Time DAW” applications (like Cubase, Sonar, Reaper…) which don’t actually apply the effect / process until you “render” or “mix down” the project.

Because Audacity applies edits immediately to the actual project data, “undoing” edits can only be done by stepping backwards through the Undo History. Audacity supports an unlimited number of undo steps, but because this requires retaining copies of all data that has been changed, the Undo data can become extremely large. The undo history is deleted when the project is closed.

What you will need to do is:

  1. Open the project
  2. Import the original file (File menu > Import > Audio). This will create a new track at the bottom of the project.
  3. Select the word or sentence that you need in the imported track (I’d suggest that you replace the whole phrase or sentence as that will be easier to get a seamless edit).
  4. “Edit menu > Remove Special > Trim” to trim the imported track down to just the part that you need.
  5. Use the Time Shift tool to align the imported clip with the original project.
  6. Edit the first track to match the imported clip.

When you export, all audio tracks are mixed down into a single file.