This kmix setting will setup your microphone for recording. I got it thru trial and error - its not perfect…

You can create a wav file of a written text using this command

echo "It's such a beautiful day! Why are you in front of the computer?" | festival --tts
echo "It's such a beautiful day! Why are you in front of the computer?" | text2wave -scale 50 -o beautiful_day.wav

Random Noise in Linux - I cannot think of any practical use for this command. You can use it for testing the speaker or something.

cat /dev/urandom  > /dev/dsp

To record a sound in wav format from Mic, just use this command…

arecord -f cd test.wav

Use Ctrl+C to stop recording

To playback the recording, use this command…

aplay test.wav