Using Windows 7, 8, or 10? To launch the Sound Settings box...
In the search box at the bottom-left, type mmsys.cpl, then click the highlighted item at the top of results screen
OR Right-click the Windows logo at the bottom-left of the screen, click the RUN item
In the box that pops up type "mmsys.cpl" and click on OK
OR right-click the Windows logo and click on Command Prompt, type mmsys.cpl and press the <enter> key.
Click the Recording tab, DOUBLE-click on the Microphone tab, then click on the Listen tab
Click the "Listen to this device" box, then click on OK
Use headphones or there may be feedback