In fact, talk's invisible! I so often do training with sales people that truly believe what they are saying is the most important. Let me be as clear as I possibly can: What you say is not the most important. It's not.
Words are not what people "hear". What you say matters less. It's what you behave that matters most. If your behavior is congruent with what you say, then, and only then do words begin to have power.
As humans we are channels of energy. We both send out and pick up signals all the time. We are, as it were, living antennas. Our five senses might serve as an example of antennas. In this respect, the sixth sense is not merely fictitious. It's for real!
When we first meet someone, our immediate impression of this person is the sum of three sample questions we are asking about other people (i.e. each other) all the time:
WHAT are you about?
WHO are you?
HOW do you do what you do?
These include everything about us, from how we smell to the energy we emulate. Even body language is but a very small fraction of the complete picture...
Our subconscious mind runs much faster than we can imagine. Before we even make conscious decisions about someone, our subconscious mind has picked up literally hundreds of signals that in sum automatically passes judgement on others, and thus influences how we consciously will act seconds later (cf groundbreaking research by Benjamin Libet). That's one of many reasons why Benjamin Libet has made it to my list of great people (see below).
In a very real sense, words are like "The Emperors New Clothes". What we do leaves us completely naked and exposed to the world around us. What we truly believe comes out much more forcefully than anything we might say. Words are invisible. In the famous words of Ralph Waldo Emerson: "I can't hear what you are saying, because your actions speak too loud".
See Vidar Top's list of GREAT PEOPLE!