Grunts, shouts and laughs communicate faster than words

Human speech is dazzlingly subtle and complex. We’re scarcely even aware of how we do it. It’s automatic; instantaneous.

And yet, for all the languages we’ve developed and for all that our comprehension has deepened, we may still respond faster – and more urgently – to non-verbal cues.

That’s the intriguing conclusion of new research from McGill University in Montreal.

“We can convey emotions in two different ways,” says Marc Pell, professor and director of McGill’s School of Communication Sciences and Disorders.

“We can do it with spoken language, or through non-linguistic vocalizations. These are sounds that aren’t words, but their acoustic characteristics convey rich emotional meanings. Grunts, for example, and all different kinds of laughter. These have very important meanings to us when we socially interact.”

Pell and his team tested 24 subjects, seeing how quickly they comprehended emotion when exposed to non-verbal sounds and nonsense speech. An EEG (electroencephalogram) machine was used to measure brain response time.

“Our research suggests that the brain very quickly distinguishes these two different types of vocalizations,” Pell explains.

“Within a tenth of a second, the brain already knows that those two things are different. It seems to direct more attention to the vocalizations, to try to figure out what they really mean. It processes them quickly in speech too, but not as fast.”

Pell says the conclusions offer new support to the older idea that such rapid responses harken back to to earlier, more primitive parts of the human brain.

“If you hear a shout, or a growl that could be menacing, we’ve adapted to where we need to react to that. We decide very, very rapidly what to do. Do I fight? Do I escape? Do I approach this person?

“Vocalizations lead to a much more immediate response, I think. And we’ve learned that that’s different from speech.”

Not only does the brain quickly register anger, Pell says it continues to probe, seeking any possible new danger signs that might require a rapid response.

“The brain keeps paying attention to this particular type of signal, because it could be threatening to us,” says Pell. “We need to keep processing, and figuring out what this means for us.”

Which leads to the intriguing conclusion:

“There are certain types of emotions that lead to different types of brain response.”

Pell adds that, while extensive research has been conducted into how humans read facial expressions, relatively little work has probed the deeper subtleties of how the ear and brain work together to comprehend an ever-changing environment.

“We also found that people who are more anxious tend to be more sensitive to things that could be threatening,” says Pell. “Our data show that people who are anxious tend to be hyper-sensitive to the emotional meanings in the voice, and their brains respond differently.”

Just for fun, listen closely to the words and voice cues you encounter today, and see how quickly you respond to the non-verbal ones.