stench vs olfactory perception

stench and olfactory perception both are nouns.

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

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

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

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

stench (noun)	olfactory perception (noun)
a distinctive odor that is offensively unpleasant	the sensation that results when olfactory receptors in the nose are stimulated by particular chemicals in gaseous form