International Journal of Primatology

, Volume 10, Issue 3, pp 199–213 | Cite as

Vocal-auditory functions in the chimpanzee: Vowel perception

  • Shozo Kojima
  • Shigeru Kiritani


The perception of vowels was studied in chimpanzees and humans, using a reaction time task in which reaction times for discrimination of vowels were taken as an index of similarity between vowels. Vowels used were five synthetic and natural Japanese vowels and eight natural French vowels. The chimpanzees required long reaction times for discrimination of synthetic [i] from [u] and [e] from [o], that is, they need long latencies for discrimination between vowels based on differences in frequency of the second formant. A similar tendency was observed for discrimination of natural [i] from [u]. The human subject required long reaction times for discrimination between vowels along the first formant axis. These differences can be explained by differences in auditory sensitivity between the two species and the motor theory of speech perception. A vowel, which is pronounced by different speakers, has different acoustic properties. However, humans can perceive these speech sounds as the same vowel. The phenomenon of perceptual constancy in speech perception was studied in chimpanzees using natural vowels and a synthetic [o]- [a] continuum. The chimpanzees ignored the difference in the sex of the speakers and showed a capacity for vocal tract normalization.

Key words

chimpanzees vowel perception perceptual constancy vocal tract normalization 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Chiba, T., and Kajiyama, M. (1941).The Vowel: Its Nature and Structure, Tokyo-Kaiseikan, Tokyo.Google Scholar
  2. Elder, J. H. (1934). Auditory acuity of chimpanzee.J. Comp. Psychol. 17: 157–183.CrossRefGoogle Scholar
  3. Elder, J. H. (1935). The upper limit of hearing in chimpanzee.Am. J. Physiol. 112: 109–115.Google Scholar
  4. Farrer, D. M., and Prim, N. M. (1965). A preliminary report on auditory frequency threshold comparisons of humans and pre-adolescent chimpanzees. Technical Report No. 65-6, 6571st Aeromedical Research Laboratory, Holloman Air Force Base, N.M.Google Scholar
  5. Fujisaki, H., and Kawashima, T. (1968). The roles of pitch and higher formats in the perception of vowels.IEEE Trans. Audio Electroacoust. AU-16: 73–77.CrossRefGoogle Scholar
  6. Fukuda, Y., Sakamoto, Y., and Kuroki, S. (1976). Promotive effect of residual hearing upon speech reading.J. Acoust. Soc. Jpn. 32: 271–276.Google Scholar
  7. Gardner, R. A., and Gardner, B. T. (1969). Teaching sign language to a chimpanzee.Science 165: 664–672.PubMedCrossRefGoogle Scholar
  8. Klatt, D. H. (1980). Software for a cascade/parallel formant synthesizer.J. Acoust. Soc. Am. 67: 971–995.CrossRefGoogle Scholar
  9. Kojima, S. (1986). Hearing, voice perception and vocal behavior in the chimpanzee.Transactions of the Committee on Speech Research/Hearing Research, Acoustical Society of Japan, S85-88/H-86-14.Google Scholar
  10. Kojima, S. (1987). Hearing in a chimpanzee.Ann. Bull. RILP. 21: 69–73.Google Scholar
  11. Kojima, S. (1988). Audition, speech perception and phonation of the chimpanzee: A search for the origin of human speech.Primate Res. 4: 44–65.CrossRefGoogle Scholar
  12. Kojima, S. (1989). A comparison of auditory functions in the chimpanzee and human.Folia primatol. (in press).Google Scholar
  13. Kuhl, P. (1979). Speech perception in early infancy: perceptual constancy for spectrally dissimilar vowel categories.J. Acoust. Soc. Am. 66: 1668–1679.PubMedCrossRefGoogle Scholar
  14. Liberman, A., Cooper, F., Shankweiler, D., and Studdert-Kenedy, M. (1967). Perception of the speech code.Psychol. Rev. 74: 431–461.PubMedCrossRefGoogle Scholar
  15. Lieberman, P. (1968). Primate vocalizations and human linguistic ability.J. Acoust. Soc. Am. 44: 1574–1584.PubMedCrossRefGoogle Scholar
  16. Lieberman, P. (1975).On the Origins of Language: An Introduction to the Evolution of Human Speech, Macmillan, New York.Google Scholar
  17. Lieberman, P. (1984).The Biology and Evolution of Language, Harvard University Press, Cambridge, Mass.Google Scholar
  18. Lieberman, P. (1986). Some aspects of dimorphism and human speech.Hum. Evol. 1: 67–75.CrossRefGoogle Scholar
  19. Marler, P., and Tenaza, R. C. (1977). Signalling behaviour of apes with special reference to vocalizations. In Sebeok, T. E. (ed.),How Animals Communicate, Indiana University Press, Bloomington, pp. 965–1033.Google Scholar
  20. Mohr, B., and Wang, W. S.-Y. (1968). Perceptual distance and the specification of phonological features.Phonetica 18: 31–45.CrossRefGoogle Scholar
  21. Peterson, G. E., and Barney, H. L. (1952). Control methods used in a study of the vowels.J. Acoust. Soc. Am. 24: 175–184.CrossRefGoogle Scholar
  22. Premack, D. (1976).Intelligence in Ape and Man, Lawrence Erlbaum Associates, Hillsdale, N.J..Google Scholar
  23. Rumbaugh, D. (1977).Language Learning by a Chimpanzee, Academic Press, New York.Google Scholar
  24. Snowdon, C. T., Brown, C. H., and Petersen, M. R. (1982).Primate Communication, Cambridge University Press, Cambridge.Google Scholar

Copyright information

© Plenum Publishing Corporation 1989

Authors and Affiliations

  • Shozo Kojima
    • 1
  • Shigeru Kiritani
    • 2
  1. 1.Primate Research InstituteKyoto UniversityKanrin, Inuyama, AichiJapan
  2. 2.Research Institute of Logopedics and Phoniatrics, Faculty of MedicineUniversity of TokyoTokyoJapan

Personalised recommendations