herald vs announce

herald is a noun but announce is not a noun.

Word	Noun	Adjective	Verb	Adverb
herald	Yes	No	Yes	No
announce	No	No	Yes	No

As verbs, herald and announce are synonyms defined as:

Other synonyms of herald include annunciate, foretell, harbinger.

herald (noun)	announce (noun)
something that precedes and indicates the approach of something or someone
(formal) a person who announces important news

herald (verb)	announce (verb)
foreshadow or presage	make known; make an announcement
praise vociferously	foreshadow or presage
greet enthusiastically or joyfully	announce publicly or officially
	give the names of