Human speech has been investigated with computer models since the invention of digital computers, and models of the evolution of speech first appeared in the late 1960s and early 1970s. Speech science and computer models have a long shared history because speech is a physical signal and can be modeled accurately. This article gives a brief overview of the use of computer models in the study of the evolution of the vocal tract. We also present a critical case study of one model that has been used to study the vocal abilities of Neanderthals. We argue that this study contains subtle but fatal flaws which invalidate the conclusions drawn from the model, illustrating the dangers of applying computer models outside the area for which they have been developed. Future models need to make use of a broader database of anatomical and physiological data from other animals, especially nonhuman primates, to understand the path leading to modern Homo sapiens.
Alemseged, Z., Spoor, F., Kimbel, W.H., Bobe, R., Geraads, D., Reed, D., et al. (2006). A juvenile early hominin skeleton from Dikika, Ethiopia. Nature, 443, 296-301.
2.
Alipour, F., Berry, D.A., & Titze, I.R. ( 2000). A finite-element model of vocal-fold vibration. Journal of the Acoustical Society of America, 108(6), 3003-3012.
3.
Arensburg, B., Tillier, A.M., Vandermeersch, B., Duday, H., Schepartz, L.A., & Rak, Y. ( 1989). A Middle Palaeolithic human hyoid bone. Nature, 338(6218), 758-760.
4.
Boë, L.-J. ( 1999). Modelling the growth of the vocal tract vowel spaces of newly-born infants and adults consequences for ontogenesis and phylogenesis . In 14th International Congress of Phonetic Sciences (Vol. 3, pp. 2501- 2504). San Francisco .
5.
Boë, L.-J., Heim, J.-L., Honda, K., & Maeda, S. ( 2002). The potential Neandertal vowel space was as large as that of modern humans. Journal of Phonetics, 30(3), 465-484.
6.
Boë, L.-J., Maeda, S., & Heim, J.-L. ( 1999). Neandertal man was not morphologically handicapped for speech. Evolution of Communication, 3(1), 49-77.
7.
Boersma, P. ( 1998). Functional phonology. The Hague: Holland Academic Graphics.
8.
Bosma, J., & Lind, J. ( 1965). Cry motions of the newborn infant. Acta Paediatrica Scandanavica , Suppl., 163, 61-92.
9.
Bowles, R.L. ( 1889). Observations upon the mammalian pharynx, with especial reference to the epiglottis. Journal of Anatomy and Physiology, London, 23, 606-615.
10.
Buhr, R.D. ( 1980). The emergence of vowels in an infant. Journal of Speech and Hearing Research, 23, 75-94.
11.
Carré, R., Lindblom, B., & MacNeilage, P.F. (1995). Rôle de l’acoustique dans l’évolution du conduit vocal humain. Comptes Rendus de l’Académie des Sciences, Série IIb, 320, 471-476.
12.
Chiba, T., & Kajiyama, M. ( 1942). The vowel: Its nature and structure. Tokyo: Tokyo-Kaiseikan. [Reprinted in 1958, Tokyo: Phonetic Society of Japan.]
13.
Coker, C.H., & Fujimura, O. ( 1966). Model for specification of the vocal-tract area function . Journal of the Acoustical Society of America, 40(5), 1271.
14.
Crothers, J. ( 1978). Typology and universals of vowel systems. In J. Greenberg, C. A. Ferguson , & E. A. Moravcsik (Eds.), Universals of human language (Vol. 2, pp. 93-152). Stanford, CA: Stanford University Press.
15.
de Boer, B. ( 1999). Self-organisation in vowel systems. Unpublished doctoral dissertation, AI-lab, Vrije UniversiteitBrussel.
16.
de Boer, B. ( 2002). Evolving sound systems. In A. Cangelosi & D. Parisi (Eds.), Simulating the evolution of language (pp. 79-97). Berlin: Springer Verlag.
17.
de Boer, B. ( 2008). The acoustic role of supralaryngeal air sacs. Journal of the Acoustical Society of America, 123(5 Pt 2), 3732-3733.
18.
de Boer, B. (in press). Acoustic analysis of primate air sacs and their effect on vocalization . Journal of the Acoustical Society of America.
19.
Dudgeon, D.E. ( 1970). Two-mass model of the vocal cords. Journal of the Acoustical Society of America, 48(1A), 118.
20.
Dunn, H.K. ( 1950). The calculation of vowel resonances, and an electrical vocal tract. Journal of the Acoustical Society of America , 22(6), 740-753.
21.
Fant, G. ( 1960). Acoustic theory of speech production. The Hague: Mouton.
22.
Fitch, W.T. ( 2000a). The evolution of speech: a comparative review. Trends in Cognitive Sciences, 4(7), 258-267.
23.
Fitch, W.T. ( 2000b). The phonetic potential of nonhuman vocal tracts: Comparative cineradiographic observations of vocalizing animals. Phonetica , 57, 205-218.
24.
Fitch, W.T. ( 2002). Comparative vocal production and the evolution of speech: Reinterpreting the descent of the larynx. In A. Wray (Ed.), The transition to language (pp. 21- 45). Oxford : Oxford University Press.
25.
Fitch, W.T., & Giedd, J. ( 1999). Morphology and development of the human vocal tract: A study using magnetic resonance imaging. Journal of the Acoustical Society of America, 106 (3 Pt 1), 1511-1522.
26.
Fitch, W.T., & Hauser, M.D. ( 1995). Vocal production in nonhuman primates: Acoustics, physiology, and functional constraints on "honest" advertisement. American Journal of Primatology, 37, 191-219.
27.
Fitch, W.T., Neubauer, J., & Herzel, H. ( 2002). Calls out of chaos: The adaptive significance of nonlinear phenomena in mammalian vocal production. Animal Behaviour , 63, 407-418.
28.
Fitch, W.T., & Reby, D. ( 2001). The descended larynx is not uniquely human. Proceedings of the Royal Society of London, B, 268(1477), 1669-1675.
Flanagan, J.L., & Cherry, L. ( 1969). Excitation of vocal-tract synthesizers. Journal of the Acoustical Society of America, 45(3), 764-769.
31.
Flanagan, J.L., & Meinhart, D.I.S. (1964). Source-system interaction in the vocal tract. Journal of the Acoustical Society of America , 36(10), 2001-2002.
32.
Goldstein, U.G. ( 1980). An articulatory model for the vocal tracts of growing children. Unpublished doctoral dissertation, Massachusetts Institute of Technology, Cambridge (MA).
33.
Henke, W.L. ( 1966). Dynamic articulation model of speech production using computer simulation. Massachusetts Institute of Technology , Cambridge, MA.
34.
Hewitt, G., MacLarnon, A., & Jones, K.E. ( 2002). The functions of laryngeal air sacs in primates: a new hypothesis. Folia Primatologica, 73, 70-94.
35.
Houghton, P. ( 1993). Neandertal supralaryngeal vocal tract. American Journal of Physical Anthropology, 90, 139-146.
36.
Ishizaka, K., & Flanagan, J.L. (1972). Synthesis of voiced sounds from a two-mass model of the vocal cords. The Bell System Technical Journal, 51(6), 1233-1268.
37.
Klatt, D.H. ( 1987). Review of text-to-speech conversion for English. Journal of the Acoustical Society of America, 82(3), 737-793.
38.
Laitman, J.T., & Crelin, E.S. ( 1976). Postnatal development of the basicranium and vocal tract region in man. In J. F. Bosma (Ed.), Symposium on Development of the Basicranium. Washington, D.C.: U.S. Government Printing Office.
39.
Lenneberg, E.H. ( 1967). Biological foundations of language. New York: Wiley.
40.
Lieberman, D.E., & McCarthy, R.C. (1999). The ontogeny of cranial base angulation in humans and chimpanzees and its implications for reconstructing pharyngeal dimensions. Journal of Human Evolution, 36, 487-517.
41.
Lieberman, P. ( 1968). Primate vocalization and human linguistic ability. Journal of the Acoustical Society of America, 44(6), 1574-1584.
42.
Lieberman, P. ( 1984). The biology and evolution of language. Cambridge, MA: Harvard University Press.
43.
Lieberman, P. ( 2000). Human language and our reptilian brain: The subcortical bases of speech, syntax and thought. Cambridge, MA: Harvard University Press.
44.
Lieberman, P. ( 2006). Limits on tongue deformation - Diana monkey formants and the impossible vocal tract shapes proposed by Riede et al. (2005). Journal of Human Evolution, 50(2), 219-221.
45.
Lieberman, P. ( 2007). Current views on Neanderthal speech capabilities: A reply to Boë et al. (2002). Journal of Phonetics, 35, 552-563.
46.
Lieberman, P., & Blumstein, S.E. (1988). Speech physiology, speech perception, and acoustic phonetics. Cambridge, UK: Cambridge University Press.
47.
Lieberman, P., & Crelin, E.S. ( 1971). On the speech of Neanderthal man. Linguistic Inquiry, 2(2), 203-222.
48.
Lieberman, P., Klatt, D.H., & Wilson, W.H. ( 1969). Vocal tract limitations on the vowel repertoires of rhesus monkey and other nonhuman primates. Science, 164, 1185- 1187.
49.
Liljencrants, J. ( 1971). A Fourier series description of the tongue profile. Speech Transmission Laboratory Quarterly Progress and Status Report, 12(4), 9-18.
50.
Liljencrants, J., & Lindblom, B. ( 1972). Numerical simulations of vowel quality systems. Language, 48, 839-862.
51.
Lindblom, B., & Sundberg, U. ( 1971). Acoustical consequences of lip, tongue, jaw, and larynx movement. Journal of the Acoustical Society of America, 50(4), 1166-1179.
52.
MacLarnon, A., & Hewitt, G.P. ( 1999). The evolution of human speech: the role of enhanced breathing control. American Journal of Physical Anthropology, 109(3), 341- 343.
53.
Maddieson, I. ( 1984). Patterns of sounds. Cambridge: Cambridge University Press.
54.
Maeda, S. ( 1990). Compensatory articulation during speech: Evidence from the analysis and synthesis of vocal tract shapes using an articulatory model . In W. J. Hardcastle & A. Marchal (Eds.), Speech production and speech modelling (pp. 131-149). Dordrecht: Kluwer Academic Publishers.
55.
Martínez, I., Arsuaga, J.-L., Quam, R., Carretero, J.-M., Gracia, A., & Rodríguez, L. (2008). Human hyoid bones from the middle Pleistocene site of the Sima de los Huesos (Sierra de Atapuerca, Spain). Journal of Human Evolution, 54, 118-124.
56.
Mermelstein, P. ( 1973). Articulatory model for the study of speech production . Journal of the Acoustical Society of America, 53(4), 1070-1082.
57.
Nearey, T. ( 1978). Phonetic features for vowels. Bloomington : Indiana University Linguistics Club.
58.
Negus, V.E. ( 1929). The mechanism of the larynx. London : Heinemann.
59.
Negus, V.E. ( 1949). The comparative anatomy and physiology of the larynx . New York: Hafner Publishing Company .
60.
Owren, M.J., Seyfarth, R.M., & Cheney, D.L. ( 1997). The acoustic features of vowel-like grunt calls in chacma baboons (Papio cyncephalus ursinus): Implications for production processes and functions. Journal of the Acoustical Society of America , 101, 2951-2963.
61.
Perkell, J.S. ( 1969). Physiology of speech production: Results and implications of a quantitative cineradiographic study. Cambridge, MA : MIT Press.
62.
Ralls, K., Fiorelli, P., & Gish, S. ( 1985). Vocalizations and vocal mimicry in captive harbor seals, Phoca vitulina. Canadian Journal of Zoology, 63, 1050-1056.
63.
Riede, T., Bronson, E., Hatzikirou, H., & Zuberbühler, K. (2005). Vocal production in a non-human primate: morphological data and a model. Journal of Human Evolution, 48(1), 85-96.
64.
Riede, T., Tokuda, I.T., Munger, J.B., & Thomson, S.L. ( 2008). Mammalian laryngeal air sacs add variability to the vocal tract impedance: Physical and computational modeling. Journal of the Acoustical Society of America, 124(1), 634-647.
65.
Rosen, G. ( 1958). Dynamic analog speech synthesizer. Journal of the Acoustical Society of America, 30(3), 201-209.
66.
Rosenberg, A.E. ( 1971). Effect of glottal pulse shape on the quality of natural vowels. Journal of the Acoustical Society of America, 49(2, Part 2), 583-590.
67.
Schroeder, M.R. ( 1993). A brief history of synthetic speech. Speech Communication, 13(1-2), 231-237.
68.
Serkhane, J., Schwartz, J.L., Boë, L.J., Davis, B.L., & Mat-year, C. ( 2007). Infants’ vocalizations analyzed with an articulatory model: A preliminary report. Journal of Phonetics, 35(3), 321-340.
69.
Stevens, K.N., & House, A.S. ( 1955). Development of a quantitative description of vowel articulation . Journal of the Acoustical Society of America, 27(3), 484-493.
70.
Stevens, K.N., Kasowski, S., & Fant, G. ( 1953). An electrical analog of the vocal tract. Journal of the Acoustical Society of America, 25(4), 734-742.
71.
Takemoto, H. ( 2001). Morphological analyses of the human tongue musculature for three-dimensional modeling. Journal of Speech, Language and Hearing Research, 44, 95-107.
72.
Titze, I.R. ( 1973). The human vocal cords: A mathematical model PartI. Phonetica, 28(3), 129-170.
73.
Titze, I.R. ( 1974). The human vocal cords: A mathematical model Part II. Phonetica, 29(1), 1-21.
van de Berg, J. ( 1955). Calculations on a model of the vocal tract for vowel /i/ (meat) and on the larynx. Journal of the Acoustical Society of America, 27(2), 332-338.
76.
Vorperian, H.K., Kent, R.D., Lindstrom, M.J., Kalina, C.M., Gentry, L.R., & Yandell, B.S. ( 2005). Development of vocal tract length during early childhood: A magnetic resonance imaging study. Journal of the Acoustical Society of America, 117(1), 338-350.
77.
Weissengruber, G.E., Forstenpointner, G., Peters, G., KübberHeiss, A., & Fitch, W.T. ( 2002). Hyoid apparatus and pharynx in the lion (Panthera leo), jaguar (Panthera onca), tiger (Panthera tigris), cheetah (Acinonyx jubatus), and domestic cat (Felis silvestris f. catus). Journal of Anatomy (London), 201, 195-209.
78.
Wilhelms-Tricarico, R. ( 1995). Physiological modeling of speech production: Methods for modeling soft-tissue articulators. Journal of the Acoustical Society of America, 97(5), 3085-3098.
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
