"audible" in the noun sense
a football play is changed orally after both teams have assumed their positions at the line of scrimmage
"audible" in the adjective sense
1. audible, hearable
heard or perceptible by the ear
"he spoke in an audible whisper"
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License