Pausing adds power; drama to your speech. Used well your silences will literally speak LOUDER than your words.Learning when to pause, and for how long, is a skill, and like all skills it improves with practice.
time to breathe properly which in turn will help settle any nervous tension you may be feeling, as well as allowing you to use your voice effectively
time to consider what you're going to say next. Very important!
time to receive, and digest the feedback you're getting from your audience.
