Different scenario for "Loss of recorded material"

I am editing very small files (less than 3 seconds).

When I export out, the last milliseconds are truncated off, and a few milliseconds of silence are added to the beginning. I tried exporting as both .m4a and .mp3. mp3 is truncated a little, m4a is truncated even more.

I have attached the original mp3 and the exported (and truncated) .mp3 and .m4a. (oops, this forum won’t let me upload a .m4a - it says - The extension m4a is not allowed.)

What am I doing wrong?

A work-around is to add a half a second of silence to the end of the original, so the truncated part is just silence. But I am probably doing something wrong for this to be happening.

Thanks for any help.

Added silence is a normal MP3 encoding artifact.

Since your files are short/small, is there a reason you can’t use a non-lossy format? (WAV or FLAC?

I haven’t heard the sound getting truncated with any format… I don’t think added silence is normal with AAC, and I don’t know about M4A, but I believe it normally uses AAC compression.