Linux Pipe Audio Output to Input - maochuanli/wiki GitHub Wiki

https://unix.stackexchange.com/questions/82259/how-to-pipe-audio-output-to-mic-input | Stackexchange.com

To sum it up

* Install pavucontrol (PulseAudio Volume Control) using apt-get or the Ubuntu Software Center.
* Open PulseAudio Volume Control. It should be in the applications menu under Sound and Video.
* Open Sound Recorder and start recording. Playing any sound at this point would be helpful, as your level indicator should react once you have finished.
* Go to the "Recording" tab in the PulseAudio Volume Control window.
* Make sure that "Applications" is selected in the drop down menu on the "Recording" tab.
* Choose "Monitor of Internal Audio Analog Atereo" from the "Record Stream from" menu in the Sound Recorder entry of the application list.