You can adjust the headset or handset volume using your PC keyboard while you are in a call. You can also adjust the headset or handset volume at any time by clicking 
and selecting Audio Panel, and adjusting the volume slider.
To increase the headset or handset volume while in a call
-
Press and hold the Ctrl key
and press the up arrow 
to increase the volume.
To decrease the headset or handset volume while in a call
-
Press and hold the Ctrl key and press the down arrow
key to decrease the volume.
You can use the volume and mute on your headset. The mute on your headset is independent and does not mute the console application.