Being from the world of radio, I feel that one can use their voice to present a whole scene or story to thousands at one go. The voice is such a powerful tool that if one uses it properly, one can portray the right feelings to the other party without coming face to face. Have you ever spoken to people who make you feel as if they are smiling while talking? What about those that talk and it feels like if the world has ended for them? What about those that speak in a tone that makes them come out as rude?
The question now is, do you realize these things when you speak to a potential employer, a dear and loved one, or just anyone for that matter? Why not make sure you are aware of such points when talking on the phone from today onwards?
Be the type of person YOU would want to talk to! Smile while talking, because it will show.. obviously, it depends on the nature of the call. But remember, people like to talk to people who make the whole talk into something nice.