iChat Icon   I can't hear anything in my chat

If you can't hear anything in your video chat, try the following:

Make sure your microphone is properly connected to your computer.
If you are using a camera with an internal microphone, make sure the camera is properly connected to your computer and is turned on.
Make sure the Mute button is not selected in the chat window.
Open System Preferences and click Sound. Check the volume setting for your computer. Make sure the Mute checkbox is not selected.