Narrator: This is Science Today. When you're speaking, do you tend to use lots of ums, ahs, likes or you knows? Pyscholinguist Jean Fox Tree of the University of California, Santa Cruz, says these common elements of natural speech, often considered undesirable, are actually helpful to listeners.
Fox Tree: People think that people who use ums and ahs are nervous and anxious and all these other kinds of things. But it's not necessarily the case that that's in fact why people use ums and ahs. In fact, ums and ahs are very related to the amount of pausing that's about to happen in speech. So if you're about to pause for a long time, you'll say Um. If you're about to pause for a short time, you'll say Ah.
Narrator: Fox Tree says people also use ums and ahs to let the listener know they're still thinking about an answer and are not just being uncooperative or stupid.
Fox Tree: So there's a real relationship there between when people say it. These words are not ignorable particles of spoken talk. They actually might serve some real function.
Narrator: For Science Today, I'm ...ah...Larissa Branin.