There are approximately 7,000 human languages spoken worldwide. In every one of them, we have expressions for pain, joy, and disgust — often conveyed through short interjections. So, Maïa Ponsonnet and her colleagues set out to explore whether these interjections share common elements across different languages.

“Across human cultures, people frequently vocalize when experiencing pain or emotional states like joy and disgust,” the researchers note in their study. “These vocal bursts may be entirely nonlinguistic, such as cries of pain or bouts of laughter, but often include linguistic elements like expressive interjections — ‘ouch,’ ‘wow,’ or ‘oops.’ Are these forms completely arbitrary, or do they share common acoustic features across languages?”

Strikingly, the researchers discovered that pain screams exhibit notable similarities across different languages, potentially hinting at pre-language origins.

Expression across languages

To conduct their analysis, the team focused on 131 representative languages from around the world. They compared nearly 500 vowels used in interjections during joyful, painful, or disgusting experiences. The goal was to determine whether these sounds were structured and whether they conveyed emotions in similar ways across diverse languages.

Their hypothesis was that expressive interjections are not arbitrary. Instead, they have an inherent structure. If true, interjections for emotions like pain, joy, and disgust would share consistent vowel patterns across human languages.

“We believe that many vocal expressions have a function. For example, babies’ cries tend to be loud and harsh, evolving to annoy parents enough to stop the aversive signal. We expect vocal expressions of pain, disgust, and joy to reflect their functions too,” said linguist Katarzyna Pisanski, one of the study co-authors.

The team found that pain interjections in particular share consistent features across languages. They typically include sounds like [a] (as in “ah”) and wide falling diphthongs (combinations like “ai” or “aw”). These patterns were observed globally, suggesting a universal tendency.

For instance, interjections expressing pain in languages as diverse as English, French, and several Australian indigenous languages all utilized similar open vowel sounds. This could be linked to the instinctive way people open their mouths widely when in pain, producing a distinct vocal pattern that draws attention and signals distress.

Where We Differ

But this similarity only carried over for pain interjection. Interestingly, the pattern was not as pronounced for interjections expressing disgust or joy.

While joy vocalizations often included front vowels like [i] (as in “ee”), there was no clear, consistent pattern comparable to that found for pain interjections. Disgust sounds were even more variable, reflecting a broader range of vowel sounds that seemed less tied to specific acoustic profiles.

This came as a surprise to researchers.

To further investigate, the team analyzed recordings of nonlinguistic vocalizations from speakers of five languages, including Mandarin Chinese, English, and Spanish. This confirmed previous observations: pain vocalizations predominantly featured open vowels, while joy was characterized by higher, more closed vowels like [i].

The findings suggest that pain vocalizations may have deep evolutionary roots. This supports the idea that such sounds are designed to attract help or signal distress effectively. If this is the case, it could mean that pain interjections are shared at a species level, perhaps a shared form of communication rooted in survival.

Still, this idea is far from proven.

But why?

It’s not clear why some types of vocalizations are similar are others or not. The authors propose further research to explore the role of sounds in language evolution and its potential applications. For instance, a better understanding of these interjections could improve natural language processing systems to better understand emotional cues. In addition, it could also offer important clues about how and why humankind developed language.

“Why did we humans start to speak, and other primates didn’t? We all produce laughter, and hundreds of species produce play-like vocalizations,” said Ponsonnet. “Yet we are the only species that evolved spoken language. Looking at these commonalities across species can help us understand where humans diverged and how,” the researcher concludes.

Journal Reference: Vowel signatures in emotional interjections and nonlinguistic vocalizations expressing pain, disgust and joy across languages, Journal of the Acoustical Society of America (2024). DOI: 10.1121/10.0032454