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Can anyone tell me what's the bit depth of AudioMoth recordings? I need to calculate file size and that's dependent on bit depth....???

3 answers3 replies

6 Comments

Jul 07, 2020

Hi Karina, AudioMoth supports exFAT so you can use any size SD card. The 4.3GB limit is imposed by the WAV file format however. Alex

Karina Townsend

Jul 07, 2020

Replying to

Ah, that's fine Alex. I've left it at FAT32 and scheduled the recording times as you suggested. Mainly a test run tonight. Many thanks for all your input, Karina.

Alex Rogers

Jul 02, 2020

Make sure that you are using version 1.4.2 of the firmware as we released a fix in correctly close the files and re-open them when the 4.3GB WAV (and FAT32) file size limit is reached. The next update to the configuration app (due this week) will also warning about the fact that files greater than this size will be split. Since the files will be split anyway, it is probably best to plan for this and use something like record for 3595 seconds and sleep for 5 seconds so that the files all start on the hour.

Karina Townsend

Jul 07, 2020

Replying to

Wow, just spotted this. OK, thanks for the advice. Have just updated to firmware 1.4.3. One question, does the AudioMoth support ExFAT and therefore larger file sizes? But it's good advice to schedule the recordings as you suggest.

Alex Rogers

Jul 01, 2020

Hi Karina, They are 16-bit WAV files. The actual bit depth varies with sample rate but we normalise the amplitude across sample rates. The values written to the SD card are all 16-bit signed values, so the total size is the header size (488 bytes) plus the size of the date (2 bytes per sample x samples per second x number of seconds duration). Alex

Karina Townsend

Jul 02, 2020

Replying to

Many thanks Alex, Incredibly helpful reply. I'm recording for a whole night but at a high sample rate - 384kHz. So a 32Gb card is going to suffice. Karina.