Alsa

Record a sample

arecord --device 'hw:3,0' --duration 5 --format 'S16_LE' >test.mp3

Notes:

• use arecord -l to list devices. Here we used card 3, subdevice 0. The format depends on device.
• in case you have an errors with Channels count non available, use -c 2

Play a sample

aplay record.mp3

Test microphone (listen your own voice)

arecord -f S16_LE -c 1 --device="hw:2,0" - | aplay -