Audibility :: Audibility (n.) The quality of being audible; power of being heard; audible capacity.
Audible :: Audible (a.) Capable of being heard; loud enough to be heard; actually heard; as, an audible voice or whisper..
Inaudibility :: Inaudibility (n.) The quality of being inaudible; inaudibleness.
Inaudible :: Inaudible (a.) Not audible; incapable of being heard; silent.