voicer vs speaker

voicer and speaker both are nouns.

Word	Noun	Adjective	Verb	Adverb
voicer	Yes	No	No	No
speaker	Yes	No	No	No

As nouns, speaker is a hypernym of voicer; that is, speaker is a word with a broader meaning than voicer:

voicer: a speaker who voices an opinion
speaker: someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous)

Other hypernyms of voicer include talker, utterer, verbaliser, verbalizer.

voicer (noun)	speaker (noun)
a speaker who voices an opinion	electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance
someone who regulates the tone of organ pipes	someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous)