The human voice is the ultimate instrument for sharing meaning. It’s range of expression is vast. It’s sensory output is greater than virtually any other sound source. Yet most of us take this marvelous communications tool for granted. The savvy public speaker will greatly enhance his or her performance by exploiting variations in the human voice.
I concentrate here on the physical mechanics of speaking. The intellectual contents can wait for other commentary. In my experience, most speakers spend too much time worrying about what they will say and too little on how they will say it.
Moreover, I limit my remarks here to the use of (American) English. English is used as a primary language by over 1/2 billion people today. It’s the second most common language in daily use after Mandarin Chinese, and the most prominent business language around the globe. Of course, there are many other languages in common use. Indeed, reportedly humans beings speak over 7,000 different languages and countless dialects. Really though, exactly what language you use is of secondary importance to this discussion. The mechanics of speech for the most part will be similar.
Let’s discuss three important components of speech mechanics: rate, volume, and pitch, plus the usefulness of silence.
RATE
In my experience, the number one speech quality that many speakers fail to understand and to exploit fully is the rate of speech. This is the speed at which language is spoken, typically measured in “words per minute” (WPS). The typical word is assumed to be 1 to 3 syllables and less than a dozen characters in length. Actual word choice – whether you tend to use shorter, more common words or longer, more technical vocabulary – will affect the rate. But I believe that effect is often minor.
Audio studies have shown that human beings speak anywhere from about 110 WPS (noticeably slow) to over 400 WPS (blazingly fast, like an auctioneer). The world record holder has spoken over 500 WPS. Most of us in daily activities communicate conversationally at about 120 to 130 WPS. Professional speakers such as broadcasters on radio & TV, and lecturers such as TED talkers, tend to talk faster, say about 150 – 170 WPS; and they do so with a high degree of speech intelligibility. Since these experts are more time constrained, they have trained themselves to pack the most information into their delivery. Despite the higher rate, listeners usually can clearly hear what they say and comprehend this information with little or no mental strain.
So how fast should you speak? For most purposes, you do not need to be like a broadcaster. An upper limit conversational rate, say around 130 to 150 WPS, is fine without visual aids. However, if you are presenting complex visual information as well, such as PowerPoint slides with text and graphs, then slow down a little, say to around 120 WPS. Remember the audience has more data to process, both what they hear you say and what they see you present on the screen(s) near you. To prepare and fine-tune your rate, time yourself by recording your remarks and timing your reading of them. Remember, total word count divided by total speaking time equals average WPS.
If you want to be a master speaker, learn to vary your rate of speech, either by the occasion or by parts of the speech structure. This approach adds interest to your contents. There are many ways to do so. For example, you can change the rate for your entire speech. Bear in mind that speaking slower can denote subject matter seriousness and information importance while talking faster can convey urgency and passion. Or you can change the rate only for portions of your speech. For instance, some effective speakers start slow and speed up later. Starting slow helps the audience form a favorable initial impression; speeding up later injects emotion and confidence to pull in even more of the audience’s attention and acceptance. Conversely, slowing down can highlight a conclusion or signal a summation. And quite simply, varying the rate during a speech is one way to mitigate listener fatigue.
If you tend to talk faster than the average person, make a conscious effort to slow down. Conversely, if you tend to talk slower than most, speed up a little. Aim for a moderate flow of words that balances economical information dissemination with audience enjoyment of your presentation.
Both fast and slow speech have potential pitfalls. If you talk fast, make sure you maintain proper enunciation. Otherwise, the audience can get left behind in your racing delivery. Your flow of meaning gets mushy as the word delivery slurs. When you talk slow, that typically means you have more pauses within the sentences in your speech. Make sure the pauses are appropriate. They should be inserted logically, such as between – not in the middle of – clauses in compound or complex sentences. (President Obama does this routinely in his formal speeches, sometimes distractingly so.) Beware too many stops. Pauses that violate syntax, or are overly numerous, confuse the hearer and grate on the ear. The audience can get bored and tune out. For example, say this:
We see therefore…the data indicates clearly…our product is superior.
And not,
We see therefore…the data…indicates clearly…our product…is superior.
VOLUME
Sound is energy propagating in a medium. It is caused by mechanical vibration from a sound source such as an engine, musical instrument, or our own vocal chords. Those vibrations oscillate particles in a medium such as air or water. If the vibrations travel in regular waves, human hearing perceives meaningful sounds rather than mere noise. Sound volume is the auditory sensation in our ears, perceiving the amount of pressure in these waves, aka the intensity of sound energy, the amplitude of the sound wave. Physics aside, volume is our psychological understanding of the physical strength of the sounds coming to us, commonly known as the degree of loudness. That depends on the initial energy emitted at the source, the medium, and the distance between the signal source and the receptor of that signal. The initial sound energy right at the source gradually degrades and is absorbed by the medium as it travels through it.
Sound intensity, aka sound pressure or sound power, is usually measured using the Decibel Scale (dB), created in the early 20th century in honor of telephone inventor Alexander Graham Bell. It’s a frequency-weighted logarithmic system (physics again!). This system ranges from from absolute quiet, or 0 dB, to a whisper at 15 dB, to average conversation across 1 meter of distance at about 60 dB, to the threshold of human hearing loss at a sustained 85 dB, to operatic singing at 100 dB, to jet engine noise at 120 dB, to…well you get the picture.
A public speaker must adjust his sound volume to the size of his audience, the distance from them, and ambient sound interfering with his delivery. That is why people use electronic amplification for larger crowds. Obviously, trial and error allow one to figure out how loud to speak for a given venue. Controlling ambient noise is very important. So shut the windows and doors, turn off noisy building systems, and ask the audience for their quiet attention. Beyond those measures, however, the expert talker learns that varying the volume of his speaking can be beneficial.
So what volume should you use? The “loud talker” can appear confident or strident depending on the subject matter and the occasion, whereas the “soft talker” can appear by turns respectful or timid. In the history of public speaking, especially since electronic amplification has eliminated the need to shout, there has been a sustained trend towards lower volumes. Speaking before a large group today often imitates an intimate, leisurely conversation with a few friends, in keeping with our increasingly informal society. Thus speaking (into the mic) in your normal voice (60 dB at source) is okay most of the time. Just keep an eye on the audience. If they appear to be restless or bored, it may be that they simply cannot hear you very well. That’s the time to speak up! Turn up the volume a little and see what happens. You have to be flexible.
Like with the rate of speech, you can vary your volume during parts of your speech to good effect. Martin Luther King Jr. had a tendency to increase his volume as he progressed through his famous civil rights speeches, enriching the drama. At the end of his iconic, 1963 “I have a Dream” speech, he practically shouts the last lines, “Free at last, free at last. Thank God Almighty, we are free at last!” Very powerful.
In contrast, when the speaker is quieter, or turns down the volume at a critical point (say to 40 dB), her softness can be calming or even draw more attention to her, as the audience “leans forward” to hear her. For example, when an audience over all is upset, such as during a crisis or at a memorial service for a departed loved one, speaking quietly defuses tension and is respectful. Your lack of negative emotion, as shown in the soothing, everyday tone of your voice, is infectious. It makes people feel better.
PITCH
The pitch of sound is related to how many vibration cycles occur over a given time, aka the sound’s “frequency”. (physics again!) Frequency is measured in Herz (Hz), or vibrations per second. One Hz equals one vibration per second. Shorter “periods” of vibration cycles mean higher frequencies and more Herz, while longer periods mean lower frequencies and less Herz. Human hearing typically can detect sound frequencies from 20 Hz to 20,000 Hz. While, the complete range of human speech is 25 to 8,000 Hz, the practical limits of speech intelligibility have been shown to be from 500 to 4,000 Hz. When we describe a sound as truly “high” (above 2,000 Hz) or “low” (below 250 Hz), we are making a pyschoacoustic judgment of sound.
The human voice is capable of a wide range of pitches, most generally within a mid-frequency band. However each of us has a speaking voice whose natural pitch is a particular frequency and a vocal range (as noted in music from high to low: soprano, mezzo-soprano, alto, contralto, tenor, baritone, bass) that varies from person to person. A discussion of scientific pitch notation is beyond this article; but it is sufficient to note that each of us has a vocal range that can be exploited in public speaking. Despite the science, when it comes to pitch as a speaking technique, it’s a fairly subjective topic.
Thus, while we usually talk in our natural voice pitch, we intentionally talk a little higher or lower as a special effect to enhance meaning. For example, when we tell a story, using dialogue between characters is often more engaging than a dry, third party recitation of facts. Assigning a different pitch to each character is an easy way for the audience to understand which one is talking at any point in time. Also, we can vary pitch to add positive or negative emotional tone to our remarks, such as humor or gravity. We can talk higher to symbolize youth and lower for age or higher for light-heartedness and lower for solemnity. The context of our remarks determines how the pitch change is understood. But be careful. The use of pitch changes is not for the novice. It take a certain finesse to pull it off convincingly without seeming odd or silly. So use sparingly at first. Unless you want to seem odd or silly of course!
SILENCE
Not talking is just as important as talking, even employing all the attributes above. New speakers often cram their speeches with unending words, a thundering herd of thoughts hell bent on scrambling to the end of the talk ASAP. In truth, taking occasional stops between complete sentences, paragraphs, or speech sections, with a judicious dose of silence, can help a speech seem more organized and be more intelligible, especially if these brief silences occur between key ideas or talking points. In an earlier essay I discussed the “the power of the pause”, particularly when timed and combined with planned movement on stage. It is worth repeating and expanding upon here.
A effective speech that informs or persuades needs a clear structure. It should not be one long soliloquy, an endless stream of consciousness, but rather an organized, modular argument that builds enlightenment and concurrence with the audience section by section, statement by statement, from introduction to closure. Interspersing a brief moment of silence between major sections signals the continuing buildup of belief and supporting evidence more effectively then telling the listener outright. Instead of announcing “my next point is…”, simply stop and then proceed again. The absence of sound signals the next part of your talk in a less officious, more subtle way. The crowd knows instinctively that a new point is coming, precisely because you paused. The absence of sound also refreshes listener cognition. Even if only for a brief instant, the hearer can relax and rest mentally. Then refreshed, he can refocus his attention once more on your performance.
Leveraging the mechanics of speech along with well prepared content is an unbeatable combination. Combining variations in vocal rate, volume, and pitch along with timely silences makes your speech more than just a useful tool. It become a thing of sensual beauty that is a joy to hear. One of my favorite speakers is historian David McCullough. He is a master of the spoken word. It does not matter what he is talking about. I just like hearing his soothing yet authoritative voice. It’s ear candy for me! You too can be like Mr. McCullough. Just concentrate on perfecting your own ultimate instrument. I assure you. Adoring crowds will appear…and they will cheer.
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