Communicating with Computer Audio and Video
When you use computer audio and video with IBM(R) Lotus(R) Sametime (R), you and your colleagues can discuss a presentation while viewing it online. You can speak into a microphone, and everyone in the meeting can hear your voice.
If your meeting includes computer video and you have a video camera attached to your computer, your video image is transmitted to everyone in the meeting when you speak into the microphone. You can also view your own video image in the My Video window, even when you are not speaking.
Preparing to use audio and video
Before you attend your first audio/video meeting, Testing and Configuring Your Sound Card.
Computer audio
When you use computer audio, any meeting participant can speak into the microphone at any time to be heard by the other participants. However, only two participants can be heard at the same time. The first two people in the meeting who begin talking become the speaking participants. If two people are already speaking at once, a third person must wait for one of them to stop speaking. The "currently talking" icon 
appears next to the name of the speaking participant in the participants list.
Video Windows
The video window is labeled Video, with a Show drop-down list to switch between "Current speaker" and "My video" views. The Current speaker window displays the person who is currently speaking in a meeting. The My Video window displays your own video image. You must have a video camera attached to your computer to view your own image, but you can view the speaking participant's image without a video camera.