alsamixer -V capture  #unmute with the m key; enable capture on the chosen control by pressing the spacebar and the word "capture" will appear in the control
amixer -v   post output here; this is your alsa-util version
amixer contents |grep -A 11 "Capture Source"    post output here; this command lists all controls that can be captured(recorded)
amixer contents |grep -A 4 "Mic"   post output here; this command lists the Mic settings
arecord -f S16_LE -c2 -r48000 -d 5 test.wav; aplay test.wav    #talk into mic for 5 seconds  or play as sound file during recording