Open Sound settings by either going to Start -> Settings -> System -> Sound or right click the volume control in your system tray (bottom right by the clock) and select Open Sound Settings
Under Input make sure the drop down is on your Jabra Link and then select Device Properties
Then change your Volume to 50%
Then you can close the settings window and your calls should be much less noisy. If you are still getting complaints you can try lowering the volume even further, though you might want to do a test call with someone else to see what the best volume is.