How to communicate you're listening:
You show you're listening with your eyes more than with your ears. Are they focused on the person speaking or are they straying to your work, to the television, to other people or other distractions? Appropriate eye contact involves meeting the speaker's eyes and looking away briefly from time-to-time to ponder points. Then, to bring your attention back to the speaker with appropriate expressions.
Assume the same body posture as the person who is speaking. It's called "rapport" in certain professional circles. By assuming the same posture, you are gaining a rapport with the speaker and showing your sympathy and making a connection.
Don't answer the phone that rings. If the speaker pauses, say "they'll leave a message...you were saying?" What you are saying when you do that is "nothing is more important to me than what you are saying right now."
Techniques for truly listening:
Techniques for truly listening are basic common sense, but often not practiced. The goals of listening are to tune in, completely understand what you hear, retain it and to be able to repeat it later.
Eye contact is doing double duty in this case. If you have good, active eye contact, chances are better that you're staying tuned in to the speaker.
To make sure you're grasping what's being said, outline what you're hearing--whether in your mind or on paper. Generally, the speaker will make major points supported by sub-points. Organizing these keeps your mind active and increases your understanding. You'll also more likely retain the thought if you're actively mulling it over while listening.
From time to time, repeat back to your conversation partner what you've heard. Let them know that you're checking your understanding. That's flattering, not insulting, especially when you repeat it back correctly. You're proving yourself to be an interested listener.
These simple tips will not only help you be a better listener, they'll improve the connections you make with each interaction. And that translates to increased trust, credibility and opportunity.
See what a little listening will do.