volume vs loudness

volume and loudness both are nouns.

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

As nouns, volume and loudness are synonyms defined as:

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

Other synonyms of volume include intensity.

volume (noun)	loudness (noun)
physical objects consisting of a number of pages bound together	the magnitude of sound (usually in a specified direction)
the magnitude of sound (usually in a specified direction)	tasteless showiness
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