Help diagnosing corrupt files

We just encountered a handful of files from the the beginning of a deployment that seem to be corrupt. There were many working normal files recorded before these so it seems strange. but then there are tons of files that are normal afterwards as well. I have attached a few examples here in the zip. The files are consecutive and seem to be limited to 1 day, so not a big data loss but curious if anyone can help diagnose what happened?

them here (I think...).

5 comments

5 Comments

Abram Fleishman

Apr 25

Hi Alex, thanks for your reply.

Here's the summary csv with those problem files toward the top.

Firmware was AudioMoth-Firmware-Basic (1.8.1)

Alex Rogers

Apr 25

Replying to

Yes, you are right. The header is at 0x4E0000 rather than 0x0 which is very strange. It is also the header for the next file, rather than the actual file. This header is in the 20231212_182000.WAV file.

I think this must be some corruption of the file allocation table, rather than the AudioMoth failing to write the header correctly.Regarding the batteries, they don't look like alkaline batteries as the voltage is very high and doesn't decrease at all across the deployment. They are possibly 1.5V Li-Ion AA cells. These have a voltage regulator that maintains the voltage at a constant 1.5 volts until the battery is depleted and then switches them off.