Sound Card

EarPhone && Speak

Both EarPhone and Speak are dual-channel interfaces

Use the aplay command to play audio in wav format

   #path-to indicates the absolute path to store the audio
   aplay /path-to/audio-name.wav

Mic

Mic is off by default. You need to turn it on to use it.

   #The command sets the default recording sound card channel.
   amixer cset numid=2,iface=MIXER,name='Capture MIC Path' 1

   #Set the default recording sound card channel.
   alsamixer
   #Set the Capture MIC Path to Main MIC

Mic records audio

   arecord -l											#View all available MIC devices.
   arecord -Dhw:0,0 -f cd -d 10 /path-to/audio.wav	#Select the sound card and record audio.
   #Note: Mic only supports mono recording