I believe that listening is a skill that is very much under developed in our society. Often times what happens when someone is speaking to us even though we hear the words we are not actually listening. The human mind is capable of taking in over 500 words per minute but most of us use only a small fraction of that ability.
What often ends up happening is that when someone is speaking to us we immediately start to interpret what they are saying based on our ideas and the things we believe. When this happens we shape our opinions of that person based on our beliefs and the things we are thinking about and often miss what the other person is trying to tell us. This can be devastating if done in the sales process.
We as human beings have a deep down desire to be understood, when we feel that people do not understand us we shut down and become hostile or distant. Conversely, if we feel that someone cares about us and listens to what we have to say we become open with that person and begin to develop trust in them.