Did you know that using your hands and arms while speaking makes you louder? Gesturing while speaking, or "talking with your hands," is common around the world. Many communications researchers believe that gesturing is either done to emphasize important points, or to elucidate specific ideas (think of this as the "drawing in the air" hypothesis). But there are other possibilities. For example, it could be that gesturing, by altering the size and shape of the chest, lungs and vocal muscles, affects the sound of a person's speech.