Source : Webster's Revised Unabridged Dictionary (1913)

Amphoric \Am*phor"ic\, a. (Med.)
   Produced by, or indicating, a cavity in the lungs, not
   filled, and giving a sound like that produced by blowing into
   an empty decanter; as, amphoric respiration or resonance.

Source : WordNet®

amphoric
     adj : the sound heard in auscultation resembling the hollow sound
           made by blowing across the mouth of a bottle; "amphoric
           breathing indicates a cavity in the lung"