How do I merge multiple AU files without AUP file?

Hello all,

I have a folder with 122 *.au files of my son telling a story when he was a toddler that I would like to recover. Unfortunately, the filenames in alphabetical/numerical ascending order is not the right order and if I sort by date modified, they don’t sort to the second or millisecond. No matter what I do, there’s no way to put them in order and merge them into one audio file (in any format), that I know of. Unless I listen to each one and try to figure out the order, which is nearly impossible, how else can I make these multiple files whole again? Is there a way to merge and recover this in Audacity? This recording is very precious to me and it’s more than 7 years old.

The closest thread I searched for and found in these forums was this one:

That thread, however, has been marked solved and was locked. The solution in that thread links to a wiki page that no longer exists. I don’t know which version of Audacity I used to record as this was several years ago. The version I have now is the latest as I was prompted to update upon launching it, 3.2.2.

Any help would be greatly appreciated!

The help article has since been moved to

I’m personally not very familiar with this process though.

Tip for the future:
When you make an important recording like that, as soon as it is finished export a WAV file as an uncompressed backup.

And better still make a copy of that backup onto at least one external device.


Thank you so much! I’m finally listening to my son’s voice from a decade ago once again!!!

For those with the same problem, even if you find the steps linked above a bit confusing, read them first. Then read my steps below and everything should make perfect sense.

Here’s what I did for my stereo files (for Windows only!):

  1. Download the xplorer2 Ultimate “Free Trial” software, as instructed in the link above. This was only necessary because in Windows File Explorer, the date and timestamps don’t show seconds and you can’t do bulk renaming. If you already have a bulk renaming software, you don’t need to download this software. You can use Bulk Rename Utility, Advanced Renamer, etc. to do bulk renaming. You can also do batch renaming using a script, if you prefer.
  2. Sort your files, whether in Windows File Explorer or xplorer2 Ultimate, by date/time in ascending order (oldest to newest). Again, Windows File Explorer will not show the timestamp including the seconds so you might see the same timestamp for multiple files. Rest assured, they are in chronological order.
  3. Rename the contents of the entire folder of *.au files as a batch so that instead of the random file naming convention (i.e.,, they will become something like all the way to In my case, since there were 122 files total in the folder, I wanted a leading ‘0’ followed by numbers according to the file’s date/time order.
  4. Once you have a folder of *.au files in numerical order, launch Audacity.
  5. Go to File > Import > Audio… (CTRL+SHIFT+I).
  6. Go to the folder’s path where you have your renamed *.au files and select all of the files. You can also simply click on one of the files and hit CTRL+A on your keyboard.
  7. This will take some time for all of the files to load and be sorted in Audacity depending on how many files you have.
  8. Once all the audio files have been loaded, select the top most track by clicking on the grey bar where the filename is. In my case, it says ‘0001’. Since my audio files are stereo, 0001 and 0002 are two channels of the same audio recording. This means that 0003 and 0004 are a pair, 0005 and 0006 are a pair, 0007 and 0008 are another pair, and so on. If your audio files are mono, you can skip steps 9 and 10. FOR MONO TRACKS, GO TO STEP 12!
  9. Once the top most track is highlighted and selected, right-click on the left pane so that a floating menu appears.
  10. Click on “Make Stereo Track”. This will combine 0001 and 0002 into a stereo track.
  11. Repeat steps 8-10 as needed to pair all of the tracks into stereo tracks. In my case, since there are 122 files, I made 61 stereo tracks total.
  12. Now that I have a bunch of stereo tracks, all I need to do now is stitch them all together into one stereo track. To do this, click on the grey bar of the second track. Since 0001 and 0002 are now my top most track, 0003 and 0004 are my my second track. I clicked on the grey bar where it says 0003.
  13. Click on “HOME” on your keyboard to move the line all the way to the beginning.
  14. Do a cut, or a “CTRL+X”, on your keyboard. This will cut the 0003 and 0004 pair causing it to disappear.
  15. Click on the top most track (0001 and 0002) and click on end to move the line all the way to the end of the track.
  16. Do a paste, or a “CTRL+V”, on your keyboard. This will paste the 0003 and 0004 pair to the end of your 0001 and 0002 pair.
  17. Click on “HOME” again to return to the beginning of the tracks.
  18. Click on the “X” (top left most) of the empty track container in order to remove it. This is the track where 0003 and 0004 used to be.
  19. Repeat steps 12-18 as necessary and before you know it, you have only one track left stitching all of the individual stereo tracks from 0001/0002, then 0003/0004, 0005/0006… 0121/0122.
  20. Finally, click on File > Export as WAV or Export as MP3. This will allow you to save the file as one whole audio file.

I hope this helps someone. I am thankful for LWinterberg for finding the link for me that gave me the confidence to do this mini project. I was so afraid to lose or corrupt this precious recording. I wanted to pass this along to others who may be in the same predicament. Good luck!

Wow - I’m so pleased you got it to work - you must have done no editing, just recording, otherwise the little files would have got very jumbled up.


It was just straight up recording and nothing else, fortunately!