It depends a bit on what is corrupt. Is it the audio or header data inside your WAV-file? Or is the WAV-file itself corrupt in the filesystem on your Olympus?
Once I was cought recording at the end of the show and was forced to format the SD-card on the spot. What I did afterwards was this:
- Put the SD card in a laptop (where it showed up completely empty of course)
- Created a disk image of the SD card. There are several tools that can do that, e.g.
https://www.osforensics.com/tools/write-usb-images.html. By copying the disk image instead of the WAV-files on the SD card (or internal memory), any filesystem errors are bypassed.
- Opened the disk image as 'raw audio file' in your favorite editor, using the parameters of your audio file. E.g. in my case it was stereo 24bit 96kHz. I had to play a bit with 'offset' (0,1,2 bytes) to make the editor parse the samples correctly.
This gave me the full recording, apart from a few corrupted samples at the very start of the show. These small parts were header data or re-written during the formatting process.
This only works if you haven't used your recorder or SD card for anything else since the mishap. Otherwise the samples in the storage have likely long been overwritten with new data. As yours was back in 2019, I guess you have been using it since, so this very likely won't work anymore.
Hence one8ung's questions are very valid: If your WAV file is small, then it likely contains just the 5 minutes of audio. If it is big, the samples beyond 5 minutes may be there but unreachable due to header corruption. Opening the file as 'raw audio' in your editor then might save your day.
If you'd need any assistance trying to rescue your recording, I'd be happy to offer my help.