Volume, the relative loudness of a speaker’s voice while giving a speech, is usually the most obvious and frequently cited vocal element in speechmaking, and with good reason. We need to hear the speaker at a comfortable level. The proper volume for delivering a speech is somewhat louder than that of normal conversation. Just how much louder depends on three factors: (1) the size of the room and of the audience, (2) whether or not you use a microphone, and (3) the level of background noise. Speaking at the appropriate volume is critical to how credible your listeners will perceive you to be. Audience members view speakers whose volume is too low less positively than those who project their voices at a pleasing volume.

Be alert to signals that your volume is slipping or is too loud and make the necessary adjustments. If your tendency is to speak softly, initially you will need to project more than seems necessary. To project your voice so that it is loud enough to be heard by everyone in the audience, breathe deeply from your diaphragm rather than more shallowly from your vocal cords. The strength of our voices depends on the amount of air the diaphragm—a large, dome-shaped muscle encasing the inner rib cage—pushes from the lungs to the vocal cords.