Public Speaking Course:
In my public speaking course I stress the importance of beginning your speech with a slightly lower than normal voice inflection. In the excitement or nervousness that many of us feel at the beginning of our presentations, it is easy to go the other way and start out with a voice inflection that is too high.
The problem with this is that if you are already at a high range or volume when you start, you have nowhere to go as you attempt to crescendo the audience to a big peak of excitement at the end of your program. You must plan ahead for this always, it really can make a big difference in how your audience perceives you.
When you present in public remember. . . start low.