loud vs audible

loud is not a noun while audible is a noun.

Word	Noun	Adjective	Verb	Adverb
loud	No	Yes	No	Yes
audible	Yes	Yes	No	No

loud (noun)	audible (noun)
	a football play is changed orally after both teams have assumed their positions at the line of scrimmage

loud (adjective)	audible (adjective)
characterized by or producing sound of great volume or intensity	heard or perceptible by the ear
(used chiefly as a direction or description in music) indicating that said piece or segment should be played loudly
tastelessly showy

loud (adverb)	audible (adverb)
with relatively high volume