Silly Questions,
Settings - Audio Wizard - Can you hear Speakers on your headset? When you Start the test?
If not check the Windows Audio for the software Zopier in the Audio Mixer.
Or
In Settings - Audio - Deivce - Output Device - LG TonePro
Also confirm your Codec's are correct for the Digium.
Settings - Preferences - Codec - remove those not needed
Advanced - Confirm rports UDP
Confirm with a cabled headset you have the same issue.
Those are what I have had in the past.
Hope it is some help...
Kind Regards
Paul.