Recovering AU-files


Yesterday I recorded two interviews. After the recordings were done I just closed the lid on my Macbook pro running on ElCapitan without saving the recordings first (very very stupid, I know). When closing the lid the laptop does not shut down. When I open the lid back home the recordings were still in Audacity and playable. I closed the lid again (without saving, had totally forgotten to do so at this stage). When later open the lid again Audacity didn’t respond so I forced quit the software, then opened it again and choose to recover the lost recordings when Audacity asked me if I wanted to do this. The problem now is that the recordings are just flat lines without audio. I went to Audacity’s Temporary folder and copied the au-files to a backup-folder on my desktop. I tried to open the au-files with Audacity but still flat-line. Then I followed the steps for Automatic recovery ( and used Audacity Recovery Utility ( after renaming the au-files in my backup-folder using a consecutive alphanumerical sequence. After this I played the wav.-files that I received from the Recovery Utility but still no audio. The files will play but there is no sound.

I realise that my recordings are probably lost but I still wanted to check with you guys since I still have the .au-files from the recordings.

Any suggestions would be much appreciated! Thank you so much!

Assuming you can read the temp folder (look at Help > Show Log…) then the AU files would indeed appear to be silence.

What does closing the lid do, if not shut down? Sleep, Safe Sleep, Hibernate?


There is only sleep that I know of.


There is also Safe Sleep, which leaves RAM powered on but also copies data to the drive:


I wonder if there’s any notice of SSDs. There’s no significant speed hit in writing to the “hard drive” since there’s no spinning platter. I understand the Air doesn’t have a mechanical SSD. The chips are mounted directly on the motherboard. Given the emphasis on long battery life, I would expect as much of the machine to shut down as possible.

With intermittent use and shutting down the WiFi when I’m not using it, I’ve been charging the Air every three or four days…and I don’t need to do that.

I haven’t tried recording sound yet…


Yes there is Standby on Macs with SSD’s.

The following seems to be the definitive article about sleep on Mac:


What does closing the lid do, if not shut down? Sleep, Safe Sleep, Hibernate?

Thank you for your replies! When I close the lid the computer enters “Safe sleep”. Apparently you can check how your mac sleeps using terminal and the command pmset -g | grep hibernate mode.

You should see one of the following responses:

hibernate mode 0 (means normal sleep and is the default for desktops)

hibernate mode 1 ((hibernate mode and is the default for older portables (pre 2005))

hibernate mode 3 (safe sleep and is the default for portables made after 2005)

hibernate mode 25 (is the same as hibernate mode, but is the setting used for newer (post 2005) Mac portables)


All that and it’s still the worst possible idea to change the computer in any way before you save the performance. Truly obsessive will Export a WAV file and Save a Project.

Then close the lid.