An echo is caused when your voice is picked up by friend's microphone and transmitted back to you. Have you tried using a headset? You can use the Hands-free mode without an echo. If you prefer to use speakers and microphones instead of a headset, one or more of the following may be used to reduce far-end echo problems (the person that needs to take these steps is not the person hearing the echo but the person at the far end of the conversation):

• Move the microphone away from the speakers as far as practical.
• Reduce the microphone level (using the volume control on the left, below the Talk button). Try talking directly into the microphone to be heard clearly.
• Reduce the speaker level (using the volume control on the right).
• If the above steps do not help, turn off Hands-free mode (remove the check from the Hands-free box) and take turns pressing the Talk button to speak. Do not leave the Talk button depressed when the other person is speaking.