Chimpanzee Utterances Refute Purported Missing Links for Novel Vocalizations and Syllabic Speech

Overview

Journal Sci Rep

Specialty Science

Date 2024 Jul 25

PMID 39054330

Authors

Axel G Ekstrom

Charlotte Gannon

Jens Edlund

Steven Moran

Adriano R Lameira

Affiliations

Soon will be listed here.

Abstract

Nonhuman great apes have been claimed to be unable to learn human words due to a lack of the necessary neural circuitry. We recovered original footage of two enculturated chimpanzees uttering the word "mama" and subjected recordings to phonetic analysis. Our analyses demonstrate that chimpanzees are capable of syllabic production, achieving consonant-to-vowel phonetic contrasts via the simultaneous recruitment and coupling of voice, jaw and lips. In an online experiment, human listeners naive to the recordings' origins reliably perceived chimpanzee utterances as syllabic utterances, primarily as "ma-ma", among foil syllables. Our findings demonstrate that in the absence of direct data-driven examination, great ape vocal production capacities have been underestimated. Chimpanzees possess the neural building blocks necessary for speech.

References

GOLDMAN H . Parental reports of 'MAMA' sounds in infants: an exploratory study. J Child Lang. 2001; 28(2):497-506. DOI: 10.1017/s030500090100472x. View

Klatt D, Stefanski R . How does a mynah bird imitate human speech?. J Acoust Soc Am. 1974; 55(4):822-32. DOI: 10.1121/1.1914607. View

Rogers C, Mooney M, Smith T, Weinberg S, Waller B, Parr L . Comparative microanatomy of the orbicularis oris muscle between chimpanzees and humans: evolutionary divergence of lip function. J Anat. 2009; 214(1):36-44. PMC: 2631558. DOI: 10.1111/j.1469-7580.2008.01004.x. View

Lieberman P . Primate vocalizations and human linguistic ability. J Acoust Soc Am. 1968; 44(6):1574-84. DOI: 10.1121/1.1911299. View

Nishimura T, Tokuda I, Miyachi S, Dunn J, Herbst C, Ishimura K . Evolutionary loss of complexity in human vocal anatomy as an adaptation for speech. Science. 2022; 377(6607):760-763. DOI: 10.1126/science.abm1574. View

Vernes S, Janik V, Fitch W, Slater P . Vocal learning in animals and humans. Philos Trans R Soc Lond B Biol Sci. 2021; 376(1836):20200234. PMC: 8422595. DOI: 10.1098/rstb.2020.0234. View

Grawunder S, Uomini N, Samuni L, Bortolato T, Girard-Buttoz C, Wittig R . Chimpanzee vowel-like sounds and voice quality suggest formant space expansion through the hominoid lineage. Philos Trans R Soc Lond B Biol Sci. 2021; 377(1841):20200455. PMC: 8591386. DOI: 10.1098/rstb.2020.0455. View

Fitch W, Huber L, Bugnyar T . Social cognition and the evolution of language: constructing cognitive phylogenies. Neuron. 2010; 65(6):795-814. PMC: 4415479. DOI: 10.1016/j.neuron.2010.03.011. View

KELLOGG W . CommunicationCommunication and language in the home-raised chimpanzee. The gesturs, "words," and be- havioral signals of home-raised apes are critically examined. Science. 1968; 162(3852):423-7. DOI: 10.1126/science.162.3852.423. View

10.

Belyk M, Brown S . The origins of the vocal brain in humans. Neurosci Biobehav Rev. 2017; 77:177-193. DOI: 10.1016/j.neubiorev.2017.03.014. View

11.

Liberman A, Mattingly I . A specialization for speech perception. Science. 1989; 243(4890):489-94. DOI: 10.1126/science.2643163. View

12.

Wich S, Swartz K, Hardus M, Lameira A, Stromberg E, Shumaker R . A case of spontaneous acquisition of a human sound by an orangutan. Primates. 2008; 50(1):56-64. DOI: 10.1007/s10329-008-0117-y. View

13.

Egnor S, Hauser M . A paradox in the evolution of primate vocal learning. Trends Neurosci. 2004; 27(11):649-54. DOI: 10.1016/j.tins.2004.08.009. View

14.

MACNEILAGE P . The frame/content theory of evolution of speech production. Behav Brain Sci. 1999; 21(4):499-511; discussion 511-46. DOI: 10.1017/s0140525x98001265. View

15.

Fitch W, de Boer B, Mathur N, Ghazanfar A . Monkey vocal tracts are speech-ready. Sci Adv. 2016; 2(12):e1600723. PMC: 5148209. DOI: 10.1126/sciadv.1600723. View

16.

Becker Y, Loh K, Coulon O, Meguerditchian A . The Arcuate Fasciculus and language origins: Disentangling existing conceptions that influence evolutionary accounts. Neurosci Biobehav Rev. 2021; 134:104490. DOI: 10.1016/j.neubiorev.2021.12.013. View

17.

Boe L, Berthommier F, Legou T, Captier G, Kemp C, Sawallis T . Evidence of a Vocalic Proto-System in the Baboon (Papio papio) Suggests Pre-Hominin Speech Precursors. PLoS One. 2017; 12(1):e0169321. PMC: 5226677. DOI: 10.1371/journal.pone.0169321. View

18.

Morrill R, Paukner A, Ferrari P, Ghazanfar A . Monkey lipsmacking develops like the human speech rhythm. Dev Sci. 2012; 15(4):557-68. PMC: 3383808. DOI: 10.1111/j.1467-7687.2012.01149.x. View

19.

Janik V . Cetacean vocal learning and communication. Curr Opin Neurobiol. 2014; 28:60-5. DOI: 10.1016/j.conb.2014.06.010. View

20.

Fedurek P, Slocombe K, Hartel J, Zuberbuhler K . Chimpanzee lip-smacking facilitates cooperative behaviour. Sci Rep. 2015; 5:13460. PMC: 4544027. DOI: 10.1038/srep13460. View