Excerpt from Troubleshooting Linux Sound by Steve Litt troubleshooting guide"
Steve says, "The speaker-test program provides a nice, easy way to provide input for your sound system. When used with no arguments, it simply supplies white noise to both speakers."
Testing an M-Audio external USB sound board it was unclear as to whether or not stereo separation was functional or if the audio was monaural (mono) since the balance slider on audio players seemed to have zero impact. Elimination of audio application software is advised to find if ALSA and your wiring are correct. Use this command:
speaker-test -c2 -t wav
As Steve advised in his article the command will alternate between left and right speaker audio dialog in a loop allowing you to listen and determine if the sound is coming from the speakers, the correct speakers and that you have functional stereo separation. You may find it useful to ensure you do not have intended left speaker audio coming out of your right speaker. If you have more than 2 channels, put the number of channels in the -c argument.
Be advised the article is very informative and we hope it remains online as well as The Steve Litt Diagnostic Tools he provides there. Thanks Steve!