Evolutionary loss of complexity in human vocal anatomy as an adaptation for speech

Author(s)
Takeshi Nishimura, Isao T. Tokuda, Shigehiro Miyachi, Jacob C. Dunn, Christian T. Herbst, Kazuyoshi Ishimura, Akihisa Kaneko, Yuki Kinoshita, Hiroki Koda, Jaap P.P. Saers, Hirohiko Imai, Tetsuya Matsuda, Ole Næsbye Larsen, Uwe Jürgens, Hideki Hirabayashi, Shozo Kojima, W. Tecumseh Fitch
Abstract

Human speech production obeys the same acoustic principles as vocal production in other animals but has distinctive features: A stable vocal source is filtered by rapidly changing formant frequencies. To understand speech evolution, we examined a wide range of primates, combining observations of phonation with mathematical modeling. We found that source stability relies upon simplifications in laryngeal anatomy, specifically the loss of air sacs and vocal membranes. We conclude that the evolutionary loss of vocal membranes allows human speech to mostly avoid the spontaneous nonlinear phenomena and acoustic chaos common in other primate vocalizations. This loss allows our larynx to produce stable, harmonic-rich phonation, ideally highlighting formant changes that convey most phonetic information. Paradoxically, the increased complexity of human spoken language thus followed simplification of our laryngeal anatomy.

Organisation(s)
Department of Behavioral and Cognitive Biology, Vienna Cognitive Science Hub
External organisation(s)
Kyoto University, Ritsumeikan University, Anglia Ruskin University, University of Cambridge, University of Southern Denmark (SDU), Cognitive Ethology Laboratory, German Primate Center, Dokkyo Medical University, Universität Wien
Journal
Science
Volume
377
Pages
760-763
No. of pages
4
ISSN
0036-8075
DOI
https://doi.org/10.1126/science.abm1574
Publication date
08-2022
Peer reviewed
Yes
Austrian Fields of Science 2012
106051 Behavioural biology, 106012 Evolutionary research, 301102 Anatomy
ASJC Scopus subject areas
General
Portal url
https://ucris.univie.ac.at/portal/en/publications/evolutionary-loss-of-complexity-in-human-vocal-anatomy-as-an-adaptation-for-speech(eaa5f1f9-03e0-4a91-895e-643fb7b9e670).html