Wordnet 3.0
NOUN (1)
1. 
 the acoustic phenomenon that gives sound a penetrating quality; 
- Example: "our ukuleles have been designed to have superior sound and projection"- Example: "a prime ingredient of public speaking is projection of the voice"[syn: projection, acoustic projection, sound projection]
WordNet (r) 3.0 (2006):
sound projection
    n 1: the acoustic phenomenon that gives sound a penetrating
         quality; "our ukuleles have been designed to have superior
         sound and projection"; "a prime ingredient of public
         speaking is projection of the voice" [syn: projection,
         acoustic projection, sound projection]