Speed of sound

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They say actions speak louder than words, but do noises deliver the message faster? A new study has revealed that human sounds are better – or at least quicker – at conveying emotions than words. 

The researchers looked into the notion that brains respond differently when emotions are expressed through vocalisations where no words are used – noises such as laughter, crying or growls, for example – than when they are expressed through language. 

They focused on three basic emotions: anger, sadness and happiness. Researchers tested 24 respondents by playing a mixture of vocalisations and ‘language-like’ nonsense speech (Jabberwocky-type words) spoken with different ‘emotional intent’. Participants were then asked to identify which emotion was being conveyed. An electroencephalogram (EEG) machine recorded, simultaneously, how quickly – and in which ways – the brain responded to each stimulus. 

Researchers found that participants not only processed vocalisations more quickly than speech, but that they paid more attention to an emotion expressed through vocalisations.

According to the study’s lead author, Marc Pell, director of McGill School of Communication Sciences and Disorders, this apparent preference for – and increased speed of processing of – vocal sounds over words can be attributed, in part, to how important decoding them has been in human survival. The areas of the brain that interpret these sounds are older, in evolutionary terms, than those that decode emotion expressed in spoken language.

“What I take as really important from these results is that we very rapidly direct our attention to non-linguistic vocal sounds, even more so than emotional speech,” said Pell. “Both signals are recognised very quickly but, somehow, the vocalisations capture our attention – at least at first.”

The results also revealed an interesting pattern: participants detected vocalisations of happiness more quickly than those conveying anger or sadness. However, angry sounds and speech produced brain activity that lasted longer than either of the other two emotions.

Some of this can be explained by the time it takes to make sense of the different acoustic information. Laughter creates a sound that is acoustically distinct from the other types of emotional expressions; it is often produced while inhaling and exhaling, for example. So at the initial stage of processing – around one tenth of a second after the noise has been made – the brain is simply making sense of what is being expressed.

At the next stage (two tenths of a second), the emotional meanings are beginning to be differentiated, and it is here that a stronger response for anger is seen. According to Pell, this can be attributed to the social significance of that emotion.

“Anger is typically expressed when we experience a barrier to realising our personal goals,” he said. “When placed in a social context – for example, two people, where one has done some harm to the other – expressing anger vocally is a potent way of trying to change the other person’s behaviour, allowing our own goals to be realised.

“It signals aggression, a warning to others to submit to our wishes, but the actions we take (Do I run? Do I fight?) – and the extent to which we believe we can cope with this threat in a particular situation – need to be analysed carefully as we hear the anger signal. This is probably why we saw the sustained and stronger anger response to both angry speech and angry vocalisations [growls].”

marketing potential

Emotional cues are often used in advertising as a means of drawing attention – an example of this being the 2009 video ad for Cow & Gate infant formula, which featured footage of laughing babies.

Pell believes that this use of laughter produces a very raw, positive response, “and, as many emotions, such as laughter, are contagious, we begin to simulate and ‘feel’ the joy of the babies for ourselves. This makes us feel good and our evaluation of the product could, therefore, be more positive”. More broadly, Pell says that non-linguistic vocalisations, whether heard in isolation, or mixed with speech and conversation, attract a lot of attention.

“I believe that one of the major goals of marketers is to capture and manipulate the consumer’s attention in certain ways – remember that emotional voices could be very useful to do this,” he says.