Last week we learned how to configure soundcards for playback with ALSA. It's easy, it works on all Linuxes, it doesn't create conflicts or introduce latency, and it doesn't require the X Window System. Today we're going to use ALSA for recording, and learn how to test our sound system.

A quick and horrid way to see if sound is working is to pipe the contents of a file to dev/dsp:

$ cat /dev/urandom > /dev/dsp

A more pleasant way is to use alsa-utils. It includes a number of useful commands for testing your setup. The speaker-test command tests your speaker channels. This example is for a simple two-speaker stereo setup:

$ speaker-test -t wav -D plug:front -c2 -l2

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