"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..."