To use tone of voice effectively for power, you need to consider three aspects: volume, speed, and inflection. Volume is how loud or soft you speak, speed is how fast or slow you talk, and inflection is the variation of pitch and emphasis. Here are some tips on how to use these aspects to your advantage: Speak loud enough to be heard clearly, but not too loud to sound rude or intimidating - this moderate volume can convey confidence and respect. Speak at a natural and comfortable pace, but not too fast or too slow - this way you can avoid implying nervousness or impatience. Vary your pitch and tone to express your emotions and interest, but not too much or too little - a monotone voice can sound dull or robotic. You can also strategically use volume, speed, and inflection to emphasize key points, create suspense or urgency, show enthusiasm or curiosity, or ask questions.