Huh? :o) OK, click Actions, then Call Setup. Follow the instructions on the screen to test your sound system.

You can also manually test your system. Here’s how:

1. Click the Speaker icon in your system tray (in the bottom-right corner of your screen) one time and click and drag the volume bar to the top. Make sure "Mute" is not checked. (If the speaker icon isn’t there, click "Start", select "Control Panel," then "Multimedia" or "Sounds and Multimedia." Make sure that the "Show volume control on the task bar" option is checked, and click OK at the bottom of the window).
2. Did that work? If not, double-click the Speaker icon. Make sure that none of the options are muted, and that all levels are turned above 50%. Then one after the other, click "Options," "Properties," "Recording" and OK at the bottom of the window. Make sure that "Microphone Balance" is the only option selected, and that the level is turned up above 50%.
3. Close the window and try to use Yahoo! Voice in Yahoo! Messenger. Better?