WAV exports too short

Audacity 2.1.2, El Capitan 10.11.6, dmg installer

I used Audacity to audio record “video lectures” from school. They can be quite lengthy (3-4 hours).

The first time I tried it, it worked beautifully. Then for the 2nd or 3rd lectures, while the “visualizer” shows that it, in fact, has been recording for 3-4 hours, when I export the audio as a wav file, it’s only 20-30 minutes. The weird thing is that the size of the file is commensurate with a long 3-4 hour audio too (3-4 gb).

I’m guessing something’s going missing while exporting?

Any help would be greatly appreciated.

Thank you.

Make sure you are not selecting audio then using Export Selected Audio.

WAV is limited to 4 GB maximum size. Some applications won’t play WAV files above 2 GB or play them incorrectly. AIFF has the same restriction. Audacity’s choice of Other uncompressed files > RF64 header is the lossless PCM format for over 4 GB. I don’t think iTunes handle RF64 or FLAC, which would be about half the size of WAV or AIFF and doesn’t have a size limit.

If you install VLC it should handle RF64 and FLAC.

You may have to accept exporting as M4A or MP3. Both require adding extra libraries for Audacity to use. Both fomats are lossy but should be acceptable enough for speech.

FFmpeg to export M4A

LAME to export MP3.