hear vs hearer

hear is not a noun while hearer is a noun.

Word	Noun	Adjective	Verb	Adverb
hear	No	No	Yes	No
hearer	Yes	No	No	No

hear (noun)	hearer (noun)
	someone who listens attentively

hear (verb)	hearer (verb)
get to know or become aware of, usually accidentally
perceive (sound) via the auditory sense
receive a communication from someone
listen and pay attention
examine or hear (evidence or a case) by judicial process