Q: My client makes many vowel errors. Can you give me some advice about teaching them?

Teaching the vowels is mostly about ear training during the production of prolonged single vowels. Don’t try to teach them within the context of words. That is way too hard.

Recent research (1,2) suggests that the vowels are easier to learn relative to one another instead of one-at-a-time.  Therefore work on all of them and not only the few your client needs to learn.

Research (3) also demonstrates that the front vowels are learn as a modification of the highest vowel /i/ (“Long E”). Therefore use E as your starting place for the front vowels, and use Oo (as in cool) as your starting point for the back vowels.

The front vowels are learned as a modification of Long E.  Therefore have the client make a Long E, and then teach him to lower the jaw until it sounds like each vowel under Long E.  Use the vowel quadrilateral as your guide.

Do the same for the back vowels, beginning with Oo.

My upcoming book, The Marshalla Guide, will contain an entire chapter about the vowels that will include much more information along these lines.

References

1. Nishi, K., & Kewley-Port, D. (2007). Training Japanese listeners to perceive American English vowels: Influence
of training sets. Journal of Speech, Language, and Hearing Research, 50, p. 1496–1509.
2. Nishi, K., & Kewley-Port, D. (2008). Nonnative speech perception training using vowel subsets: Effects of vowels in sets and order of training. Journal of Speech, Language, and Hearing Research, 51, p. 1480–1493.
3. Lindblom, B., & Sundberg, J. (1971). Acooustical consequences of lip, tongue, jaw, and larynx movement. Journal of the Acoustical Society of America, 50, p. 1166-1179.