(n.) One who utters.

agreeable rattle babbler big talker blab blabber blabberer blabbermouth blatherer busybody chatterer conversationalist gabber gabbler gasbag gibble-gabbler gossip great talker hot-air artist idle chatterer jabberer jay magpie moulin a paroles newsmonger patterer prater prattler quidnunc rattle sayer scandalmonger speaker tabby talker tattletale utterer windbag windjammer word-slinger