When the speaker perceives you are interested, it creates a feeling of mutual respect. This is an instant rapport builder. There is little that is more frustrating than the feeling that someone you are talking to isn't listening. This feeling is most likely to emerge when the listener is a passive listener. There is nothing that will destroy rapport faster than having clients believe you don't listen to them.
Speakers look for certain cues that acknowledge the message is being received.
When speakers don't notice the cues they are looking for, they get the impression you aren't listening. There are a number of ways to acknowledge the speaker, create rapport and improve the quality of your communication. When the speaker is speaking you should give both auditory and visual signs that you are listening. The placement of these cues is important. They shouldn't be continuous or random.