Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Separable processing of consonants and vowels


There are two views about the nature of consonants and vowels. One view holds that they are categorically distinct objects that play a fundamental role in the construction of syllables in speech production1,2,3. The other view is that they are convenient labels for distinguishing between peak (vowel) and non-peak (consonant) parts of a continuous stream of sound that varies in sonority (roughly the degree of openness of the vocal apparatus during speech)4,5,6, or that they are summary labels for bundles of feature segments7,8. Taking the latter view, consonants and vowels do not have an independent status in language processing. Here we provide evidence for the possible categorical distinction between consonants and vowels in the brain. We report the performance of two Italian-speaking aphasics who show contrasting, selective difficulties in producing vowels and consonants. Their performance in producing individual consonants is independent of the sonority value and feature properties of the consonants. This pattern of results suggests that consonants and vowels are processed by distinct neural mechanisms, thereby providing evidence for their independent status in language production.

Your institute does not have access to this article

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Performance in repetition of a set of words seven or eight phonemes in length.


  1. McCarthy, J. A prosodic theory of nonconcatenative morphology. Linguistic Inquiry 12, 373–418 (1981).

    Google Scholar 

  2. Clements, G. N. & Keyser, S. J. CV phonology: A Generative Theory of the Syllable LI Monograph Series no. 9 MIT Press, Cambridge, MA, 1983).

    Google Scholar 

  3. Yip, M. Reduplication and C-V skeleta in Chinese secret languages. Linguistic Inquiry 13, 637–661 (1982).

    Google Scholar 

  4. Selkirk, E. in The Structure of Phonological Representations (eds van der Hulst, H. & Smith, N.) Part II (Foris, Dordrecht, 1982).

    Google Scholar 

  5. Goldsmith, J. A. Autosegmental and Metrical Phonology (Blackwell, Oxford, 1990).

    Google Scholar 

  6. MacNeilage, P. F. The frame/content theory of evolution of speech production. Behav. Brain Sci. 21, 499–546 (1998).

    CAS  PubMed  Google Scholar 

  7. Kenstowicz, M. Phonology in Generative Grammar (Blackwell, Oxford, 1994).

    Google Scholar 

  8. Stevens, K. Acoustic Phonetics (MIT Press, Cambridge, MA, 1998).

    Google Scholar 

  9. Miceli, G., Laudanna, A., Burani, C. & Capasso, R. Batteria per l'Analisi dei Deficit Afasici (Centro di Promozione e Sviluppo dell' Assistenza Geriatrica, Roma, 1994).

    Google Scholar 

  10. Romani, C., Granà, A. & Semenza, C. More errors on vowels than consonants: An unusual case of conduction aphasia. Brain Language 55, 144–146 (1996).

    Google Scholar 

  11. Blumstein, S. E. in Syllables and Segments (eds Bell, A. & Hooper, J. B.) 189–200 (North Holland, Amsterdam, 1978).

    Google Scholar 

  12. Canter, G. J., Trost, J. E. & Burns, M. S. Contrasting speech patterns in apraxia of speech and phonemic paraphasia. Brain Lang. 24, 204–222 (1985).

    CAS  Article  Google Scholar 

  13. Romani, C. & Calabrese, A. Syllabic constraints in the phonological errors of an aphasic patient. Brain Language 64, 83–121 (1998).

    CAS  Article  Google Scholar 

  14. Roelofs, A. Phonological segments and features as planning units in speech production. Lang. Cogn. Processes 14, 173–200 (1999).

    Article  Google Scholar 

  15. Boatman, D., Hall, C., Goldstein, M. H., Lesser, R. & Gordon, B. Neuroperceptual differences in consonant and vowel discrimination: as revealed by direct cortical electrical interference. Cortex 33, 83–98 (1997).

    CAS  Article  Google Scholar 

  16. Buckingham, H. The scan-copier mechanism and the positional level of language production: evidence from phonemic paraphasia. Cogn. Sci. 10, 195–217 (1986).

    Article  Google Scholar 

  17. Beland, R., Caplan, D. & Nespoulous, J.-L. The role of abstract phonological representations in word production: evidence from phonemic paraphasias. J. Neurolinguistics 5, 125–164 (1990).

    Article  Google Scholar 

  18. Christman, S. S. Uncovering phonological regularity in neologisms: contributions of sonority theory. Clinic. Linguist. Phonetics 6, 219–247 (1992).

    CAS  Article  Google Scholar 

  19. Ramus, F. & Mehler, J. Language identification with suprasegmental cues: a study based on speech resynthesis. J. Acoust. Soc. Am. 105, 512–521 (1999).

    ADS  CAS  Article  Google Scholar 

  20. Nespor, M. & Vogel, I. Prosodic Phonology (Foris, Dordrecht, 1986).

    Google Scholar 

  21. Levelt, W. J., Roelofs, A. & Meyer, A. S. A theory of lexical access in speech production. Behav. Brain Sci. 22, 1–75 (1999).

    CAS  PubMed  Google Scholar 

Download references


This research was supported by a grant from the NIH. We thank S. Blumstein, A. Costa, P. Jusczyk, J. Mehler, V. Savova, N. Schiller and K. Stevens for helpful suggestions, and K. Domoto-Reilly for her help in the scoring of the data.

Author information

Authors and Affiliations


Corresponding authors

Correspondence to Alfonso Caramazza or Gabriele Miceli.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Caramazza, A., Chialant, D., Capasso, R. et al. Separable processing of consonants and vowels. Nature 403, 428–430 (2000).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing