Chapter 10. Audio, Video, and Games 103In Figure 10-4, you see that there are several files to choose from. The files that end in .ogg are OggVorbis files, a popular new audio file format, while the .pls file is an audio playlist file. You can useXMMS to add audio files into a list and then save it as a playlist. This can be convenient if you haveseveral audio files and you want to categorize them (for example, by genre or artist). Highlight the fileyou wish to play (if you have multiple files, click and hold the mouse button and drag it over all of thefiles you want to open) and click OK. Notice that XMMS begins to play your audio files immediately.To adjust the volume click and drag the volume slider (the long slider above the Open button) to theleft to lower the volume or to the right to increase it, like you would when using a CD player. Thereare also buttons to stop, pause, and skip (backward and forward) your audio files.To learn more about using XMMS and its many options, refer to the man page by entering man xmmsat a shell prompt.10.3. Troubleshooting Your Sound CardIf, for some reason, you do not hear sound and know that you do have a sound card installed, you canrun the Sound Card Configuration Tool utility.To use the Sound Card Configuration Tool, choose Applications => System Settings => Sound-card Detection. A window opens, prompting you for your root password.NoteMost sound cards are supported by Red Hat Enterprise Linux, but there are some sound cards thatare not completely compatible or may not work at all. If you are having trouble configuring your soundcard, check the Hardware Compatibility List at http://hardware.redhat.com/hcl/ to see if your card issupported.The Sound Card Configuration Tool utility probes your system for sound cards. If the utility detectsa plug and play sound card, it automatically tries to configure the correct settings for your card. Youcan then click the Play test sound button to play a sound sample. If you can hear the sample, selectOK and your sound card configuration is complete.TipIt is possible that your sound has been muted. To check this, click on the Volume Control icon on thetop Panel. Check the Volume Control application available from the Applications (the main menuon the panel) => Sound & Video => Volume Control. If any of the mute boxes have been checked,un-check them and try the Sound Card Configuration Tool again.