aroma vs olfactory perception

aroma and olfactory perception both are nouns.

Word	Noun	Adjective	Verb	Adverb
aroma	Yes	No	No	No
olfactory perception	Yes	No	No	No

As nouns, olfactory perception is a hypernym of aroma; that is, olfactory perception is a word with a broader meaning than aroma:

aroma: a distinctive odor that is pleasant
olfactory perception: the sensation that results when olfactory receptors in the nose are stimulated by particular chemicals in gaseous form

Other hypernyms of aroma include odor, odour, olfactory sensation, smell.

aroma (noun)	olfactory perception (noun)
any property detected by the olfactory system	the sensation that results when olfactory receptors in the nose are stimulated by particular chemicals in gaseous form
a distinctive odor that is pleasant