There is a robotic quality to the voice recorded by Descript to train for overdub voice. And there are times when the app clearly fails to record properly. It should be possible to do this properly, and would make overdub sound more natural. Otherwise a very clean, studio-quality sound file recorded outside of this app is needed to achieve a decent overdub voice. The overdub feature is a great innovation, but it deserves more attention to be complete. And it's not complete.