Wordnet 3.0
ADJECTIVE (1)
1. 
 the sound heard in auscultation resembling the hollow sound made by blowing across the mouth of a bottle; 
- Example: "amphoric breathing indicates a cavity in the lung"
The Collaborative International Dictionary of English v.0.48:
amphoric \am*phor"ic\ ([a^]m*f[o^]r"[i^]k), a. (Med.)
   Resembling a sound like that produced by blowing into an
   empty bottle; especially, a respiratory sound heard over
   cavities in the lungs during percussion and auscultation; as,
   amphoric respiration or resonance.
   [1913 Webster + AS]
WordNet (r) 3.0 (2006):
amphoric
    adj 1: 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"