What is the best way to export audio from Audacity to create the highest quality sound for a podcast?
16-bit WAV @ 44100Hz is CD quality.
However your podcast-host will probably transcode your WAV files into another format, reducing the quality to some extent in the process.
highest quality sound for a podcast?
You should do all your recording, production, filtering, corrections, effects, etc, etc, in WAV (Microsoft). If you’ve ever created one of those you know there are no “quality” settings. It’s always perfect.
You should have two. One WAV when you finish live recording (raw work), and another WAV when you’re ready to submit your edit master. A crash in the middle of production editing is not an excuse to read it again. Just open up the raw WAV and re-edit. Resist the New User trap of posting corrections and edit work on top of the old recording. That destroys the backup.
From there you can make whatever the client or audience wants. In the case of an AudioBook for example, ACX requires you to post MP3. If you did everything right up until now, the MP3 should sound perfect. The AudioBook people have rules for posting. Consult with whoever hosts your podcast.
Do Not Edit your MP3. If you lose a show or need to re-edit for production reasons, go back to the Edit Master WAV and cut that. Then make a new MP3. Don’t touch the raw recording. If you find yourself hosting two different versions of the same podcast, make two Edit Master WAVs.