Corrupt file from ZOOM h4n after battery died

Dear everyone - help will be highly appreciated!

I am a journalist, and the battery of my ZOOM h4n died while I recorded an interview. I replace the batteries with new ones, and continue my interview.

BUT when I get home and try to transfer the clip from the SD card to my Macbook it will not transfer. It says error code 36.

This interview is very important to me, and for this reason I am crossing all my fingers that someone here can help.

I have tried opening the file in Audacity as raw sound, but this only gives me less than a minute of the file (it’s 32 minutes and 20 seconds). The same thing happens when I open it with VLC player - it shows 32 minutes, but after about 50 seconds, I get an error message.

Any help will make me so happy. I am so scared that I will lose this important half an hour of interview.

Best regards,

I don’t think there’s much we can do to help.

If you recorded as WAV, then “Import RAW” will import as much as Audacity is able to read.
A stereo WAV file at CD quality (16-bit 44.1 kHz) uses about 10 MB per minute, so the file size can give you an idea about how much audio exists in the file.
(A mono WAV file is half the size per minute of a stereo WAV file.

MP3 files are typically around 15% of the size of a WAV file, but don’t work with Import Raw because MP3 data is encoded, not RAW.

If the recording is very important, you could try one of the many “data recovery” services. We can’t make recommendations as there are thousands of such companies, and we don’t allow “advertising” on this forum. Professional data recovery services are quite expensive, and unlikely to offer guarantees, so this is really a last resort for very important projects only.

Thanks for your reply. It says that the file is 342,8 MB, and it’s a WAV-file.
So there should be something there - I don’t know why it does not open.


If you could upload the file to a public file sharing site (such as “” or “dropbox”), then I will take a look to see what I can see.
Wherever you post it, please ensure that the file has access without requiring registration.

I replace the batteries with new ones, and continue my interview.

By my count you should have two sound files. One of my recorders “knows” the batteries are going and after it makes a fuss about it (BEEEEP!!), goes ahead and saves the work…just before it dies.

Which sound file do you have?


Audacity has that Open Raw thing where you can tune manually how the work is opened. It doesn’t need the file headers and other fancy file info.

You can analyze an older, successful file to see what’s supposed to be there, and then tell Audacity what to expect when it opens the damage.
Screen Shot 2017-11-22 at 14.11.50.png

Photo Rec” is free software to recover corrupted files.
Despite the name, it doesn’t just recover photos.
I’ve only used it on Windows, but it’s available for Mac OS X (& Linux).