In a study of how people talk in English, the linguist Mark Liberman analyzed a massive database of spoken language and found that one in every sixty words people pronounce is either um or uh. Depending on how fast you talk, this means you are producing two to three of these ‘fillers’ per minute.
Why do we do this? An obvious answer is that we use these fillers when we are momentarily unable to say what we want to say. We might be having trouble remembering a word or a name, or formulating our thoughts, or we might have reason to be hesitant. But there is more to it than this. Just having a problem finding the words you want to say is not enough reason to say something like um out loud. You could just as well stay silent for a moment while you work away in your head to sort out what you are saying.
The reason we say “um” and “uh” is that, in the high-speed to-and-fro of conversation, going silent won’t work.
Why we need filler words in conversation
In everyday conversation, there is no script. We don’t know who is going to talk and when, what they are going to say, when someone else will jump in, or how long anyone will talk for. But because people in conversation tend to obey a one-speaker-at-a-time rule, we are always having to deal with the question of who has the floor, when they intend to hold on to it, and when they are giving it up. The cooperative rules of conversation require us to use traffic signals that regulate the flow of social interaction.
Suppose you are having trouble formulating your next phrase: If you go silent, the other person may figure that you have finished your turn at talking, and they may take over the line of conversation. If this happens, you have potentially lost your thread forever, as the conversation goes in an unpredicted new direction. So, if you are temporarily delayed and are intending to continue, it makes good sense to use a filler like um or uh. The filler is a traffic signal that accounts for your delay: “Please wait a moment, I’m not done yet, normal transmission will soon resume.” If the other person is cooperating, as people usually are, they will refrain from taking over the floor.
Despite the fact that fillers like um and uh have clear functions in conversation, we are often told to avoid them. The problem is that, in informal conversation at least, if you were to eliminate all of your ums and uhs, you would find people assuming you had finished your turn, and they would start speaking when you weren’t actually done yet.
You could be rid of filler words if you could be free of the underlying reasons why they are there, i.e., if you were always ready to say what you wanted to say in the split second of time you have available in which to say it. But in free-flowing conversation, you will always and unavoidably experience delays, and if you don’t use the right conversational traffic signals, you are going to be a poor or strange conversational partner.
How public speaking is different
Nobody speaks with perfect fluency all the time. But we do tend to speak more fluently under certain conditions, for example when we are talking about a topic that we know well, when we are saying things that we have said before, and when we are not under time pressure. These conditions cannot be guaranteed in free-flowing conversation. We don’t usually know in advance exactly what we are going to say. We don’t get to rehearse. Nor can we control what the topic of conversation is going to be. This is because any conversation is a joint project, and it is designed on the fly, and in a collaborative way, by the two or more people engaged in conversation.
In public speaking, the situation is different. In public speaking, we do get to decide (and rehearse) in advance what we are going to say. So, with good planning we can ensure that the words and ideas we are articulating are readily accessed, meaning we can be more fluent and avoid the need for fillers.
Second, in public speaking, one of the main functions that fillers fulfil—namely, to let the other person know not to start their turn yet—is not relevant. The floor is all yours, at least until Q&A. So, leaving more than a second or so of silence does not present the problem that it does in informal dialogue.
Third, in public speaking we are not engaged in the fast-paced to-and-fro of conversation, and so we are free to determine the temporal rhythm of our own speech.
The best strategy for eliminating filler words in public speaking: Slow down
By consciously slowing down, we give ourselves more time to formulate what we are saying (and our audience gets more time to process it), and we thereby decrease the likelihood of the cognitive pressures that lead to delays, and in turn to ums and uhs.
Slowing down has other benefits as well: When we speak more slowly, we come across as more authoritative and relaxed.
Targeting um and uh themselves does not solve the problem. They are merely symptoms. If we are going to minimize our use of fillers, and benefit from the impression of control and authority that this gives, we should understand the good reasons why these conversational traffic signals exist in the first place.
N.J. Enfield is a professor of linguistics at The University of Sydney and author of “How We Talk: The Inner Workings of Conversation.”