Similarities of persuasive speeches and persuasive essays:
Both communicate information to their live or reading audience.
Differences of persuasive speeches and persuasive essays:
Persuasive speech is delivered to a live audience it needs to be more descriptive and entertaining, presenting a tone that produces an emotional effect on the audience. At the end od each section, it's important to restate the point.
Perusasive essay: in general it is used to comunicate to a general audience. At the conclusion, the information is synthesized.