Q: What articulation developmental norms do you use?

I don’t use any specific developmental norms because of the following:

• Lieberman (1980) found that a rudimentary vowel quadrilateral is set in infant vocal productions by 5 months of age.
• According to a recent chapter by Vihman (2004), research demonstrates that average children acquire basically all the consonant phonemes by 3 years of age.
• All studies that have been done since Templin in 1957 have demonstrated that all the consonants reach adult form by 8-9 years of age, once the permanent teeth are in place.

Using the norms as a basis of deciding when to enroll clients in therapy is a remnant of an earlier age. Stimulability and readiness are more important determining factors today.

However, if you have to use them, the newest norms can be found in Smit et al (1990).

References

• Lieberman, P. (1980). On the development of vowel production in young children. In Yeni-Komshian, G., & Kavanaugh, J., & Ferguson, C. A. (Eds.) Child Phonology, Volume One: Production. New York: Academic Press.
• Smit, A. B., & Hand, L., & Freilinger, J. J., & Bernthal, J. E., & Bird, A. (1990). The Iowa articulation norms project and its Nebraska replication. Journal of Speech and Hearing Disorders, 55, 779–798.
• Templin, M. C. (1957). Certain Language Skills in Children: Their Development and Interrelationships. Minneapolis: University of Minnesota.
• Vihman, M. M. (2004). Early phonological development. In Bernthal, J. E., and Bankson, N. W. Articulation and Phonological Disorders. Boston: Pearson. P. 63-104.