Testing the Sound Card

To test the sound driver, you should try playing a sound file. A good way to do this is to insert an audio CD-ROM into your CD-ROM drive, and play a sound track. See the section "Playing Audio CD-ROMSs" for more information about various CD Player applications.

If you don't have an audio CD-ROM handy, you can use the X Multimedia System (XMMS) to open and play a sound file. XMMS can play many types of sound files, including MP3 and Windows WAV. You will find many WAV sound files-which usually have names that end with the .wav extension-in the /usr/share/sounds directory of your CentOS Linux system.

To play a sound file, start XMMS from the GNOME desktop by selecting Main Menu>Sound & Video>Audioo Player. The X Multimedia System has a simple user interface. To open a sound file, select Window Menu>Play File, or press L and select a .wav file from the Open dialog box. Select a file from the /usr/share/sounds directory, and then click the play button. XMMS starts playing the sound file.

If you get an error message from XMMS, select Window Menu>Options>Preferences, and select the OSS Driver as the Output Plugin. If you want to adjust the volume or other attributes of the sound, start the volume control by selecting Main Menu>Sound & Video>Volume Control from the GNOME desktop.

If you have a microphone connected to your sound card, you can try recording a 10-second sound file with the following command:

dd bs=8k count=10 </dev/audio >test.au

The dd command simply copies a specified amount of data from one file to another. In this case, the input file is the audio device (which records from the microphone), and the output file is the sound file. You may have to run the volume control program to set the recording-gain level for the microphone. After recording the sound file, you can play it back by sending the data back to /dev/audio with the following command:

cat test.au > /dev/audio