When you are giving a speech, you want to grab the audience's attention immediately. Doing so will not only engage the individual people in your subject, but it will also help hold their attention throughout the speech. You can even refer back to your attention getter throughout the speech to reaffirm the idea.
Share a Story
Tell the audience a story that relates to your speech. If you are giving a speech at a recurring event, consider telling a tale about a time you were at the event in the past. Make the story relevant to the audience and speech content. For example, if you are trying to motivate high school students to go to college, tell about your own struggles with college applications. Do not read off of notecards -- just tell the story to make it come alive.
Describe Shocking Statistics
Use a statistic that will have an intense impact on your audience to get them to pay attention. For example, if you are discussing the dangers of drunk driving, start with the number of people who are killed every year in drunk driving accidents. If you are trying to convince people to eat healthier, inform them about the amount of calories in an average- or even small-sized meal at a fast food place that the crowd may frequent.
Ask a Question
Ask a question at the beginning of your speech. Perhaps you are speaking at a town meeting on the school budget. Ask how the audience would feel if art and music had been removed from their own educational experiences or how these disciplines affected their lives in a positive way. You can pose the question as a rhetorical one as well. If you are hosting a discussion or a debate, open up the floor to the other members.
Tell a Joke
Lighten up the mood a little bit. Sometimes people need an icebreaker to truly feel comfortable in an environment. Make sure you do not make fun of your audience. Additionally, if you are discussing a serious subject, you should not make a mockery out of it, or people will not take you seriously. You can even tease yourself a little bit because it will make the audience feel closer to you.