"When I read the part(s) about practicing out loud it reminded me of things I learned about practicing the trombone when I was a professional trombonist.
When I was preparing for a concert or for an audition I would record my practicing (in those days a decent “Walkman” would provide a reasonable recording). I would then listen to it three times:
(1) once to get out (and get rid of) my super self-critical chatter (which is meaningless, really),
(2) once to focus on what was wrong in the recording, and
(3) once to focus on what was right in the recording.
I learned that if I had a clear mental (or aural) image of how I wanted to sound and if I just noticed where my performance was not matching up with that mental image, when I played it next I would correct many things automatically.
A speaker has to have a clear idea of what they want to communicate and let that guide their practice.
Given time constraints, it is easier to use this system with short segments (phrases, not whole movements) of a musical piece (or of a presentation).
A speaker or presenter could use this approach to practice their presentation with respect to each slide or each group of slides."
I could not agree more - even with the listening to the recording three times. We must practice OUT LOUD in order to make what we want to say match up with what actually comes out of our mouths. (or in Isaiah's case, his trombone).