loudness vs volume

loudness and volume both are nouns.

Word	Noun	Adjective	Verb	Adverb
loudness	Yes	No	No	No
volume	Yes	No	No	No

As nouns, loudness and volume are synonyms defined as:

loudness and volume: the magnitude of sound (usually in a specified direction)

Other synonyms of loudness include intensity.

loudness (noun)	volume (noun)
the magnitude of sound (usually in a specified direction)	physical objects consisting of a number of pages bound together
tasteless showiness	the magnitude of sound (usually in a specified direction)
	the property of something that is great in magnitude
	a publication that is one of a set of several similar publications
	the amount of 3-dimensional space occupied by an object
	a relative amount