Lesson 1 Criteria for Success

Emotions Are the Heart and Soul of Vocal Power in Public Speaking
As the discussion above shows, the power of your voice ultimately depends not so much on mechanics, as it does your ability to connect with listeners. Urgently conveying a message to others who share your passion or commitment to that content is, indeed, an avenue to power as a speaker. 
As surprising as that knowledge may be, is the fact that you need to invest as much in emotions as the verbal content of your presentations. Emotions rule when it comes to persuading and activating audiences, since the more important the decision any of us makes, the more that decision will be colored by emotion. Here are 5 ways to achieve emotional power in speeches and presentations.
As speaker, your response must be no less emotional than your audience. In fact, if you're reading this article, you’re already emotionally invested in your public speaking performances. Why else would you care if you achieve a powerful speaking voice as a presenter?
How Our Body Language Reflects Our Emotions
Here, it’s helpful to remember the nature of how we ourselves respond to emotions. What we feel usually finds an outlet in what we show physically. When we’re truly sad, we cry; when we’re happy, we smile. The voice, which is produced physically, is no less a player in this equation than any other aspect of body language. So allow yourself to feel and express the emotions that inform what you’re saying (business speakers often resist this level of commitment).
Your voice—so perfectly designed to respond to what you’re thinking and feeling—will reflect the deep investment you have in what you’re saying. And it will do so automatically and without any conscious thought. Again, your focus on what your listeners receive will serve you far better in your actual performance, than an approach that involves consciously aiming for an effect.
The late great Yogi Berra said you can’t think and hit at the same time. And in a sense, it’s equally true that you can't think and speak at the same time. But you’d better be playing your emotions if you want to speak with honesty and power.