An explanatory speech (also known as a briefing) is similar to the descriptive speech in that they both share the function of clarifying the topic. But explanatory speeches focus on reports of current and historical events, customs, transformations, inventions, policies, outcomes, and options. Whereas descriptive speeches attempt to paint a picture with words so that audiences can vicariously experience it, explanatory speeches focus on the how or why of a subject and its consequences. For instance, a speaker might give a descriptive speech on the daily life of Marie Antoinette, or an explanatory speech on how she came to her death. If a manager wanted to inform employees about a new workplace internet use policy, she might cover questions like: Why was a policy implemented? How will it help? What happens if people do not follow established policies? Explanatory speeches are less concerned with appealing to the senses than connecting the topic to a series of related other subjects to enhance a deep understanding (3). For example, to explain the custom of the Thai wai greeting (hands pressed together as in prayer), you also need to explain how it originated to show one had no weapons, and the ways it is tied to religion, gender, age, and status.
Sample Explanatory Speech
Title: Giant Waves, Death, and Devastation: The 2004 Indian Ocean Tsunami (17)
Specific Purpose: At the end of my speech, my audience will be aware of the nature of the 2004 Tsunami and the destruction it caused.
Central Idea: The 2004 Asian Tsunami was one of the worst natural disasters in human history in terms of magnitude, loss of human life, and enduring impact.