Hedda Hopper's Dictation Machine

Origin
Hedda Hopper was a waning actress who later on became a notorious writer for the Los Angeles Times gossip column. Labeled “Hedda Hopper's Hollywood”, she maintained an intense rivalry with rival columnist Louella Parsons. Many of her articles degraded actors and celebrities by accusing them of sexual relationships (Katharine Hepburn and Spencer Tracy, Joseph Cotten and Deanna Durbin) and other affairs (Charlie Chaplin’s political alignment, Douglas Fairbanks, Jr’s non-enlistment in American armed forces). When the McCarthy era hit California, she repeatedly released names of suspected communists.

Effects
Information spoken into the receiver will be implanted into the subconscious of people the user comes into contact with and spread from there. As more people "know" the thought, the more it comes to the forefront, until it grips people into a fervor.