Mild, um, speech pauses are persuasive

U. MICHIGAN (US) — To be successful in speaking situations, it’s best to remember an old adage: Everything in moderation.

A new study finds that people who spoke, fast, but not too fast; with a pitch, but not too high or low; and with a few short pauses were the most successful in convincing the listener to take a desired action.

“Interviewers who spoke moderately fast, at a rate of about 3.5 words per second, were much more successful at getting people to agree than either interviewers who talked very fast or very slowly,” says Jose Benki, a speech scientist at the University of Michigan with a special interest in psycholinguistics.


Males with higher pitched voices have worse success in persuasion than deeper-voiced men, but for women, pitch doesn’t seem to matter. (Credit: U. Michigan)

For the study, Benki used recordings of 1,380 introductory calls made by 100 male and female telephone interviewers and analyzed the interviewers’ speech rates, fluency, and pitch, and correlated those variables with their success in convincing people to participate in the survey.

People who talk really fast are seen as—well, fast-talkers out to pull the wool over our eyes, and people who talk really slow are seen as not too bright or overly pedantic, so findings about speech rate make sense, Benki says. But he says another finding was counterintuitive.

“We assumed that interviewers who sounded animated and lively, with a lot of variation in the pitch of their voices, would be more successful.”But in fact we found only a marginal effect of variation in pitch by interviewers on success rates.

“It could be that variation in pitch could be helpful for some interviewers but for others, too much pitch variation sounds artificial, like people are trying too hard. So it backfires and puts people off.”

Pitch, the highness or lowness of a voice, is a highly gendered quality of speech, influenced largely by body size and the corresponding size of the larynx, or voice box. Typically, males have low-pitched voices and females high-pitched voices—stereotypically, think James Earl Jones and Julia Child.

Researchers also examined whether pitch influences survey participation decisions differently for male compared to female interviewers. Males with higher-pitched voices had worse success than their deep-voiced colleagues.
There was no clear-cut evidence that pitch mattered for female interviewers.

The last speech characteristic the researchers examined for the study was the use of pauses. Here they found that interviewers who engaged in frequent short pauses were more successful than those who were perfectly fluent.

“When people are speaking, they naturally pause about 4 or 5 times a minute,” Benki says. “These pauses might be silent, or filled, but that rate seems to sound the most natural in this context. If interviewers made no pauses at all, they had the lowest success rates getting people to agree to do the survey. We think that’s because they sound too scripted.

“People who pause too much are seen as disfluent. But it was interesting that even the most disfluent interviewers had higher success rates than those who were perfectly fluent.”

Benki and colleagues plan to next compare the speech of the most and least successful interviewers to see how the content of conversations, as well as measures of speech quality, is related to their success rates.

More news from University of Michigan: www.ns.umich.edu/