During my career in broadcasting, I spent years coaching news reporters, anchors and talk show hosts in how to be comfortable and confident when behind the microphone. How to project their voice and inject enthusiasm. How to use their nervous energy to amplify their performance and how to eliminate audible pauses, such as "ums," "ers" and "ahs."
Over the past 15 years in public relations, I have provided similar public speaking training to literally hundreds of organizational spokespersons with great results. Frequently, I will have an executive voice concern about their stumbling and stammering and we work to break down some of the bad habits that can contribute to audible pauses. They worry that they may be making their audience mad.
But until today I had never heard of disfluency, let alone how disfluent speakers can actually be better at making their umm point and getting their err message across.
My wife, a subscriber to Self magazine, tore out a page for me with a story stating that more people remember the points made by those who aren't smooth presenters. The pauses actually accentuate an audience's understanding.
It was no coincidence that I had recently pointed out the ubiquity of "you know" in my wife's lexicon (in a totally supportive way, of course)! 
I had to learn more, so I read through the actual study,  "It’s the way that you, er, say it: Hesitations in speech affect language comprehension," by Dr Martin Corley and Lucy MacGregor, Edinburgh University's School of Philosophy, Psychology and Language Sciences, and David Donaldson of the University of Stirling. Sure enough, it found that disfluency becomes a useful interruption to the expected ritual of a speech or presentation.

The researchers from Edinburgh and Stirling Universities invited volunteers to listen to a number of sentences, including sentences with disfluencies. They conducted a series of tests to find out how well the listeners could recall what was said.
It turned out that the "ers" inserted into the sentences had a significant effect on the ability of the subjects to remember the information. After hearing typical sentences with inserted disfluencies, the volunteers got 62 per cent of words correct compared to 55 per cent for sentences with no stumbles.
This really isn't as unexpected as it may seem. Great presenters, much like great actors, will use the pace of their speech and pauses of varying lengths to emphasize key points. Bill Curtis, the longtime TV news anchor at the CBS affiliate in Chicago is the best example I can think of, adding drama to virtually every story with pauses here and there. Dan Rather did it, too.
They weren't using ers and ums. Just silence. But it has the same impact on grabbing attention as these researchers found, which is why we train our speakers to embrace silence as a powerful tool and the best way to eliminate/replace audible pauses.
Whether using ums, ers or simply silence, the audience says to itself, "We better pay attention now, because what I expected was going to happen is in fact not going to happen."
Just last night, I lifted my head from my magazine during a commercial break because an ad with nothing but music went on for a full 60 seconds. About 45 seconds into it, I had to look up because what I unconsciously expected -- words -- did not happen. The ad worked; it prompted me to pay closer attention.
So the important point I hope you, dear reader, take away is (silent pause) strategically interrupting your smooth speaking pattern can significantly enhance your presentation. I don't think a presenter who litters their speech with ums and ers can come off sounding confident and prepared, so I will continue to emphasize silent pauses and work to eliminate and replace audible pauses.
Learn more about DPK Public Relations' Presentation Skill Training services. To schedule a training session for your organization's spokespersons, call 214-432-7556, e-mail dan@dpkpr.com or complete the contact form on this page.