Canons Speech communication is similar to other forms of rhetoric because it uses the five canons to effectively get a point across to an audience. Invention is key to speech. This is especially true if the speech is improvised or invented on the spot. Arrangement is important to speech communication, but not especially different from other modes of rhetoric. However another canon, style , is essential to the effectiveness of a speech.
Style uses pathos to help persuade the audience.
The tone of voice, the level of language, the body language used, and even jokes that are added all effect the strength of the speech. If a speech is boring or odd then it will not be effective. Memory is a canon that is not as important as it once was. Today politicians that give speeches use electronic messages or glance at a written speech before them. Now even some arguments are fought out over the computer without speech ever occurring.