Imagine the variation in sound between the leftmost and the rightmost keys of a piano. This variation represents the instrument’s pitch, or range of sounds from high to low (or vice versa). Pitch is determined by the number of vibrations per unit of time; technically, the more vibrations per unit (also called frequency), the higher the pitch, and vice versa.² The classic warm-up singing exercise “Do re mi fa so la ti do” is an exercise in pitch.

Vocal pitch is important in speechmaking—indeed, in talk of any kind—because it powerfully affects the meaning associated with spoken words. For example, say “Stop.” Now, say “Stop!” Hear the difference? The rising and falling of vocal pitch across phrases and sentences, termed intonation,³ conveys two very distinct meanings. Intonation, or pitch, is what distinguishes a question from a statement:

It’s time to study already.

It’s time to study already?

As you speak, pitch conveys your mood, level of enthusiasm, concern for the audience, and overall commitment to the occasion. When there is no variety in pitch, speaking becomes monotonous. A monotone voice is the death knell to any speech. Speakers who are vocally monotone rapidly lose the audience’s attention and goodwill. The famous comedian Ben Stein is just about the only speaker we know who uses monotone effectively—and that is because his content is so sharp. The best way to avoid speaking in monotone is to practice and listen to your speeches with a recording device. If you have a recording device on your smart phone, you can use it to test your voice. You will readily identify instances that require better intonation.