A few years back The New York Giants won the Super Bowl with two running backs nicknamed Thunder and Lightning. Thunder was Brandon Jacobs and Lightning was Ahmad Bradshaw.
In the first half, Jacobs (aka Thunder, 6’ 4” ; 264) would wear down the opposition, and then, when they were tired and bruised, Bradshaw, ( aka Lightning, 5’ 10”; 214) would enter the fray and bolt through them. It was a good strategy.
However, in real life, thunder comes after lightning because light travels faster than sound. (You know, you count the seconds between the lightning bolt and the thunder clap to figure out how close the storm is.)
As a public speaker, just as lightning comes before thunder, your image arrives a millisecond before your sound. So, before you start speaking you have already said who you are because they’ve already seen you and formed a snap judgment.
That said, you haven’t really spoken yet. When you actually begin to address them, you have the chance to say something that will give them a more clear and complete picture of your power.
Consider your voice the thunder.