On Debut, please go to 'Options' and under the 'Audio' tab, please check 'Speakers' and/or 'Microphone'.
If still this will not work, please set your sound card or "Stereo Mix" option as your Windows default recording device before trying again. Go to Control Panel > Sound > Recording menu > select your sound card or Stereo Mix and set it as default. If these options are not listed, right click on the blank area, select "Show disabled devices", look for the option, select, click "Set default", click OK.
When ready, go to Debut options > Audio > check mark Microphone and Speakers boxes and click OK to retest.
Thank you.