I am a pastor who speaks three times each week. In order to gain my hearers' attention, I have to be interesting in content as well as voice inflection, tempo and volume.
In addition, I do the play-by-play for our local high school football team.
I have a master's degree and as stated previously, speak three times each week. In addition, I have done television commercials.
NA
As a public speaker and one who listens intently to others speaking, I constantly look for the edge in communicating. Personally, I think the key is to (1) gain the hearer's attention and then hold it and (2) to develop a level of trust by using your voice. If the client/customer doesn't trust the voice they hear, then the time has been wasted in terms of the message attempted to being communicated.