Variations in the human vocal tract could have influenced our language diversity
Vocal tracts and the sounds they produce vary, resulting in distinct sounds in speaking groups
PLOS
image:
Vocal tract outlines for the five vowels [i], [e], [a], [o] and [u] in the midsagittal plane producing a vowel sound. Each color represents a different vowel and speaker, showcasing markedly different vocal tract and tongue configurations across speakers and vowels.
view moreCredit: Tiena Danner and Christoph Zollikofer (CC-BY 4.0, https://creativecommons.org/licenses/by/4.0/)
The anatomical differences in our vocal tracts could be one of the sources of our Tower of Babel—the vast difference in languages spoken around the world, according to a study published October 13th in the open access journal PLOS Biology by Steven Moran and Tiena Danner from the University of Neuchâtel, Switzerland, and colleagues.
Many variations exist in the human voice. People vary in the size and shape of the tissues in the head and neck and also shape that anatomy differently to produce similar sounds. Developmental and cultural factors will shape the way people speak. To better understand how anatomical and articulatory variation might affect how a speaker sounds, the authors of this study analyzed data from 32 speakers (16 male and 16 female) from the USC 75-Speaker Speech MRI Database, an open-source collection of real-time Magnetic Resonance Imaging (rtMRI) conducted during speech tasks, focusing on American English vowels (i, e, a, o and u).
The authors found that the subjects had widely different vocal tracts and used very different ranges of motion in those tracts to produce the same sound. Those ranges of motion, or articulatory differences, were a result of each person’s specific vocal anatomy, and produced both the correct sound and an individual acoustic difference. Finally, by combining the rtMRI results with multilingual speech data, they showed that the amount of variation within other languages such as Basque or Hindi was similar to the variation present in American English, suggesting that within each language, there’s a basic level of speaker variation as a result of vocal tract anatomy.
While the sample size of vocal tracts was small, and the authors compared variations in only a few language families, the authors propose a biocultural model of how spoken sounds might vary and diversity between peoples, where variation of pronunciation within a group feeds into the development of a language difference between groups, eventually producing two groups that can’t understand each other.
The authors add, “We often think of differences in pronunciation between speakers of a language as noise to be normalized away in linguistic analysis. However, the results of our study suggest the opposite: that the variation between individuals may be an important source of information in understanding the evolution of spoken languages.
“An exciting aspect of our study is that it provides researchers with a null model for studying the phonetic evolution of spoken languages. If the differences between the world's 7000 or so languages reflect variation already present in the anatomical differences between speakers, we now have a baseline against which we can identify sociocultural or historical factors that have driven language diversification.
“Every person has a slightly different vocal tract and speakers compensate for these differences to remain mutually intelligible. Nevertheless, our anatomical differences leave systematic acoustic signatures in the sounds we produce. Remarkably, we find that the same patterns of phonetic variation between individuals are also reflected in the difference between languages.
“Our results suggest that the seeds of phonetic differences between languages are already present in the variation between individual speakers. Spoken language evolution is driven by the biological diversity within populations and the sociocultural forces that shape how languages change.”
In your coverage, please use this URL to provide access to the freely available paper in PLOS Biology: https://plos.io/4xMv0qQ
Citation: Moran S, Danner T, Ponce de León MS, Zollikofer CPE (2026) Interindividual vocal tract diversity influences the phonetic diversification of spoken languages. PLoS Biol 24(10): e3004003. https://doi.org/10.1371/journal.pbio.3004003
Author countries: Switzerland, South Korea
Funding: SM and TD were funded by the Swiss National Science Foundation (PCEFP1_186841, EVOPHON). The funders played no role in the study design, data collection and analysis, decision to publish, nor preparation of the manuscript.
Journal
PLOS Biology
Method of Research
Observational study
Subject of Research
People
No comments:
Post a Comment