You can adjust the ringer volume using your PC keyboard
while your console is ringing. You can also adjust the ringer volume
at any time by clicking 
and selecting Audio Panel, and adjusting
the volume slider.
To increase the ringer volume while a call is ringing
Press and hold the Ctrl key
and press the up arrow 
to increase
the volume.
To decrease the ringer volume while a call is ringing
Press and hold the Ctrl key and press the down arrow
key to decrease the volume.
Important: To ensure that the ringer will be audible
in the case of emergency calls, do not mute the volume in the Windows
Sound Panel or turn the volume off on the speaker itself.