Don’t you still believe that words only account for 7% to reach effective communication, do you? We already discussed that false belief.
In reality, to succeed in your communication efforts, you need to concentrate on verbal, vocal, and body language/facial expressions at the same time.
Every word must be chosen with care, it should be spoken in the right tone, with the right gestures. They should be 100% consistent.
It’s not easy, but it’s worth it. The only way to reach a great level of consistency is through a dry-run or multiple dry-runs.
Don’t be misled into thinking that it’s something that’s not worth for technical presentations. It’s even more important for technical people because it’s so rare and precious when you attend a consistent session; you’ll immediately feel the difference, and you want to be able to do the same.
P.s. I’m not criticizing Mehrabian’s work; I’m trying to stop people from misinterpreting it in the context of public speaking. It’s clear that you cannot express EMOTIONS with words, vocals, and gestures that aren’t aligned, people will trust your vocals and gestures more than your words in that case, but that’s all. You shouldn’t generalize it to every other context!