Professor Jochen Zeller, Associate Professor in Linguistics in the College of Humanities, is part of an international research team, led by experts from the University of Birmingham and the Leibniz-Centre General Linguistics (ZAS), Berlin, that discovered that iconic vocalisations can convey a much wider range of meanings more accurately than previously supposed. Zeller is also a co-author of the research paper.

The study reveals that the ‘missing link’ that helped our ancestors to begin communicating with one another through language may have been iconic sounds, rather than charades-like gestures – giving rise to the unique human power to coin new words to describe the world around us.

It was widely believed that, in order to get the first languages off the ground, our ancestors first needed a way to create novel signals that could be understood by others, relying on visual signs whose form directly resembled the intended meaning.

The researchers tested whether people from different linguistic backgrounds could understand novel vocalisations for 30 different meanings common across languages and which might have been relevant in early language evolution.

These meanings spanned animate entities, including humans and animals (child, man, woman, tiger, snake, deer), inanimate entities (knife, fire, rock, water, meat, fruit), actions (gather, cook, hide, cut, hunt, eat, sleep), properties (dull, sharp, big, small, good, bad), quantifiers (one, many) and demonstratives (this, that).

The team published their findings in Scientific Reports (https://www.nature.com/srep/), highlighting that the vocalisations produced by English speakers could be understood by listeners from a diverse range of cultural and linguistic backgrounds.

Participants included speakers of 28 languages from 12 language families, including speakers of two African languages (Berber and isiZulu), and groups from oral cultures such as speakers of Palikúr living in the Amazon forest, and speakers of Daakie on the South Pacific island of Vanuatu. Listeners from each language were more accurate than chance at guessing the intended referent of the vocalisations for each of the meanings tested.

Said Zeller, ‘This study makes an important contribution to our understanding of language evolution. Regardless of their specific linguistic or cultural background, humans are able to produce and comprehend non-linguistic vocalisations that express a variety of meanings. This suggests that not only signed, but also spoken, language may have iconic origins. It’s fantastic that UKZN, as the only participating African university, and isiZulu speakers, contributed to this research.’

An online experiment allowed researchers to test whether a large number of diverse participants around the world were able to understand the vocalisations. A field experiment using 12 easy-to-picture meanings, allowed them to test whether participants living in predominantly oral societies were also able to understand the vocalisations.

The research team found that some meanings were consistently guessed more accurately than others. In the online experiment, for example, accuracy ranged from 98.6% for the action ‘sleep’ to 34.5% for the demonstrative ‘that’. Participants were best with the meanings ‘sleep’, ‘eat’, ‘child’, ‘tiger’, and ‘water’, and worst with ‘that’, ‘gather’, ‘dull’, ‘sharp’ and ‘knife’.

The researchers highlight that while their findings provide evidence for the potential of iconic vocalisations to figure in the creation of original spoken words, they do not detract from the hypothesis that iconic gestures also played a critical role in the evolution of human communication.