When making calls on my Alias phone, I can't hear the other person talking but they can hear me! PLEEEASE HELP?

When I 'm the one making the call, i can't hear it ring and i can't hear the other person talking, but they can hear me fine. When I'm being called, i answer and hear nohting, but they, again, hear me. Is there ANY way i can fix this without spending a million bucks?? :// Any help is MUCH appreciated!