There can be two possible causes to this problem. Before you diagnose this problem try using more than one audio CD. There is a chance that your CD is faulty. If the problem persists, then double-click the "Volume" icon. In the dialog that opens up, make sure that the volume of "CD Player" is high and that "Mute" unchecked. Another possiblecause of this problem may be your hardware.

There is a chance that there is no connection between the sound card and the CD-ROM. Open up your computer case and check for a connection between your AUDIO OUT and your sound card. This may appear as a wire between the AUDIO OUT at the back of your CD-ROM that connects to the CD-IN on the sound card. If this connection is missing then you need to head to your vendor.