Tone matters for trusting people with different accents

A new study shows that we tend to believe speakers who sound the same as us, although much depends on their tone of voice.

Imagine you’re in a strange neighborhood, your cell phone’s dead, and you desperately need to find the closest garage. A couple of people on the street chime in, each sending you in opposite directions. One person sounds like a local and speaks in a nonchalant manner, while the other uses a loud, confident voice but speaks with a strong accent. Who are you going to trust?

Unless they speak in a confident tone of voice, you’re less likely to believe someone who speaks with an accent. And, interestingly, as you make this decision different parts of your brain activate, depending on whether you perceive the speaker to be from your own “in-group” or from some type of “out-group” (e.g., someone with a different linguistic or cultural background).

The findings appear in the journal NeuroImage.

Are you in or out?

“There are possibly two billion people around the world who speak English as a second language—and many of us live in societies that are culturally diverse. As we make decisions about whether or not to trust people who are different from us we pay a lot of attention both to visual cues and to a person’s voice,” says Marc Pell, the senior author of the study from McGill University’s School of Communication Sciences and Disorders.

“Here, we wanted to better understand how we make trust-related decisions about other people based strictly on their speaking voice.”

Check out these sound clips and see which speak you believe:

Overall, the researchers found that making trust-related decisions about accented speakers is more difficult due to our underlying bias favoring members of our own group. They also discovered that different regions of the brain activate to analyze whether to believe speech from “in-group” and “out-group” members.

Indeed, the brain needed to engage in additional processes to resolve the conflict between our negative bias towards the accent (“Don’t believe!”) and the impression that the speaker is very sure of what they’re saying (“It must be true!”).

Confidence speaks volumes

While the study’s results suggest that making trust-related decisions about accented speakers is more difficult, the data also show that when speakers with a regional or foreign accent use a very confident voice, people judge their statements to be equally believable to native speakers of the language.

“What this shows me is that, in future, if I want to be believed, it may be in my interest to adopt a very confident tone of voice in a whole range of situations,” says Xiaoming Jiang, a former post-doctoral fellow at McGill and now associate professor at Tongji University, who speaks English as a second language and is the first author on the paper.

“This is a finding that potentially has repercussions for people who speak with an accent when it comes to everything ranging from employment to education and the judicial process,” Jiang says.

A two-step process

Earlier research has shown that people are more likely to believe statements produced in a confident tone (voiced in a way that is louder, lower in pitch, and faster) than those spoken in a hesitant manner. The researchers wanted to see whether the same areas of the brain were activated as we made trust-related decisions about statements made in an accent that is different from our own.

When making decisions about whether to trust a speaker who has the same accent as us, the researchers discovered that the listeners could focus simply on tone of voice. The areas of the brain that were activated were those involved in making inferences based on past experience (the superior parietal regions). Whereas when it came to making similar decisions for “out-group” speakers, the areas of the brain involved in auditory processing (the temporal regions of the brain) were involved to a greater extent.

This suggests that as listeners made decisions about whether to trust accented speakers they needed to engage in a two-step process where they needed to pay attention both to the sounds that an accented speaker was producing as well as to their tone of voice.

Study participants (who all spoke Canadian-English as their mother tongue) listened to a series of short, neutral statements spoken with varying degrees of confidence in accents ranging from the very familiar (Canadian-English) to the somewhat different (Australian-English and English as spoken by Francophone-Canadians).

The researchers then asked participants to rate how believable they found each statement. As participants listened, researchers used a brain imaging technique (fMRI) to capture areas of brain activation to see whether there were differences between the participants’ responses to “in-group” and “out-group” speakers, both in general and depending on their tone of voice.

The Natural Sciences and Engineering Research Council of Canada (NSERC) partially funded the research.

Source: McGill University