esdcat plays a raw audio stream through the daemon. esdmon outputs the mixed stream from the daemon. esdrec outputs from the sound device's current input.
esdcat [options] [file=stdin]
esdmon [options] [file=stdout]
esdrec [options] [file=stdout]
NOTE: options for esdcat, esdmon, and esdrec default to 16 bit (signed), stereo, 44.1kHz