Let's take communication to a different aspect. Take for instance, communication via internet/e-mail/instant messaging. If you can't hear or see the person you are communicating with, how can you listen to them? You can type words, but the recipient can't really know the true emotion behind them. When you talk to one another, hear each others voices, then you can know the emotion behind the words.
The following article might help you understand the point I am trying to make.
The Artless Science of Communication
A friend called me up yesterday with a problem most of us have probably come across in one way or another. Her problem was she was using email to establish a rapport with a potential date. She had been using email as a social networking tool for some time now, and after catching and then losing so many potential partners in a wink of an eye she began to see the mistakes she was making as her inability to write with a true voice.
“I think I just offended another man.”