What might cause tracks to be out of tune when exported?

[steve]

One thing that jumps out to me is the down-grade from 24 bit to 16 bit. This is like doing a compression of an already compressed file. Each compression scheme sets limits on what can be captured and digitalized, when uncompressed, it cannot sound like the original as some content was dicarded during the original conversion and can not be replicated or replaced. Now you're taking a 24 bit file and compressing it even more, down to 16 bits and more content gets discarded. Even equalization can't make up for the content loss.

While it is true that converting from 24 bit to 16 bit may reduce the sound quality very very slightly, there is no way that such a conversion in itself could account for a change in pitch. At most it will add a tiny (virtually inaudible) amount of distortion or noise.

[steve]

Just listened to that audio clip you linked to (thanks for that)... it doesn't seem to be as dramatic a shift in pitch as that. Sounds like the 44 sample is a whole step lower than 48 sample. Definitely less subtle than what I'm experiencing.

In light of the above, it does seem as if Audacity resamples automatically when saving, if you've changed the rate in the drop down menu.

Is there anything else that could potentially alter the pitch of recordings after exporting?

Have you checked the pitch before exporting?
Have you tried importing the exported file back into Audacity?
Is there a difference in length between the original audio project (before exporting) and the length of the file if you import it back into Audacity?

How are you playing the audio file when it sounds out of tune?